三峡水库水体甲基汞光化学降解特征及其作用机制与影响因素
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摘要
自上世纪50-70年代日本发生震惊世界的环境公害事件-“水俣病”以来,环境汞污染问题受到世界各国的高度重视。自此,汞的环境地球化学行为研究成为环境研究领域的热点与重点方向。研究证实新建水库具有“汞的活化效应”,是典型的“汞敏感生态系统”。其淹没的陆地(土壤和植被)向水体释放汞、底部厌氧环境生成的甲基汞(MMHg)是水库水体和鱼体内MMHg的主要来源。三峡水库是世界最大年调节型水库,水位涨落使库区周围形成垂直高度为30m、面积约350km2的消落带。约在每年的2月至6月,水库处于水位下降期,裸露的消落区将会被用作农耕地或长有大量草本植被；约从9月份起水位开始上涨,消落区被淹没,被淹没的土壤和植被会迅速向水体释放无机汞(IHg)和MMHg,且底部处于厌氧环境,有利于MMHg生成并向上覆水体释放。因此,这种周期性消落使得三峡水库年年具有新建水库的特征,可能存在“汞的活化效应”,有可能造成上覆水体和鱼体内MMHg浓度升高,属于典型的“汞敏感生态系统”。然而,目前三峡水库水体MMHg的生物地球化学行为还少见报道。
表层水中的MMHg发生光化学降解反应在水体汞的生物地球化学循环过程中占有重要地位,是水环境中MMHg去甲基化反应的主要路径,同时也是水环境中MMHg浓度维持在较低水平的重要原因。在比较不同水域MMHg光降解的速率与对区域汞循环影响时发现,不同水环境间MMHg光降解速率、对区域汞循环的影响具有较大的差异。目前,实地水环境中的MMHg光降解研究主要集中在欧美水域,而在三峡水库这种典型的水环境系统中,其水文特征与已开展MMHg光降解研究水域的有较大的差异,且MMHg的光化学行为特征仍不明了。因此,三峡水库作为典型的水生生态系统,很有必要探究MMHg在其水域的光化学行为特征及机制。
研究发现,水环境的MMHg光降解受多种因素的影响,如光照和波长是影响MMHg光降解的主要影响因素；·OH、1O2等自由基团参与或促进MMHg光降解反应过程;悬浮颗粒物、DOM、盐度等会降低MMHg的光降解反应速率；也有研究称MMHg光降解不受水体化学组成等因素的影响,仅受光照条件的影响。虽然目前关于实际水环境中的MMHg光降解行为已开展了相关的科学研究,但对于自然水体MMHg的光降解机制、路径等仍不明了,特别是氯盐、硝酸盐在MMHg光降解过程中的作用机制、对降解产物光化学行为的影响等仍不明确,且部分研究结果还存在有较大的争议。
基于MMHg光降解在水体汞迁移、转化及循环过程中的重要地位,探究新建水库水体汞生物地球化学行为的必要性及重要性,以及目前三峡水库水体MMHg的光化学行为特征、影响因素、降解机制仍不明了,本研究以三峡水库为研究对象,选择典型消落区域的涪陵、忠县和奉节作为研究地点,探究三峡水库水体MMHg光降解的速率、通量、影响因素及降解机制,考察了Cl-、N03在MMHg光降解过程中的作用机制以及对降解产物光化学行为的影响。结果发现：
1)三峡水库水体甲基汞光降解特征
光照波长与强度对三峡库区水体MMHg光降解速率具有明显的影响作用。在水体表层,由UV-B引发的MMHg光降解速率最大,其次为UV-A引发的,可见光(PAR)引发的光降解的速率较小。UV-B、UV-A和PAR对对表层水体MMHg光降解的总速率的贡献分别为17.14%-21.30%、48.57%-61.54%和17.16%-34.29%。在水体表层,由于光照强度的作用,各波段引发的MMHg光降解速率具有明显的季节差异性,其中夏季的降解速率最高,其次为春季,冬季的光降解速率最低。在每个研究地点,各波段光照引发的MMHg光降解速率均随水深度的增加而呈现逐渐减小的趋势,其中UVB波段引发的光降解速率下降趋势最大,在水深10cm处基本降为0;其次为UV-A,由该波段引发的降解速率约在水深40cm处降为0,PAR波段光波穿透能力最强,可引发水深2.5m处的MMHg发生光降解反应。
MMHg光降解通量存在较大的季节性差异(p<0.01)。夏季降解通量最大,为7.46-18.15ngm-2d-1,其次为春季(3.33-8.01ng m-2d-1),再次为秋季(1.02-2.71ng m-2d-1),冬季最小,为0.06-0.15ngm-2d-1。忠县段水域MMHg年降解通量最大,为2.92μg m-2y-1，其次为奉节段水域(2.42μgm-2y-1),最小的为涪陵段水域(1.13μgm-2y-1)。每一波段对整个水体MMHg降解通量的贡献有很大的差异,UV-B的贡献为7.47%-18.12%,UV-A的贡献为23.22%-50.58%,PAR的贡献为32.31%-69.13%。因此,对整个水体而言,UV-A和PAR对三峡水库水体MMHg光降解起关键作用。
悬浮颗粒物、DOM、C1和NO3-对库区水体MMHg光降解具有重要影响,而Fe(Ⅲ).CU(Ⅱ)、 Mn(II)等重金属离子对对库区水体MMHg光降解的影响作用甚微。逐步回归分析结果显示,光照强度、悬浮颗粒物、DOM、 Cl和NO3-是影响三峡水库表层水体MMHg光降解的因素。光照强度对回归结果贡献最大,达到91.6%,其余变量贡献8.4%。通径分析结果表明,太是光照强度与NO3-具有很高的直接正向作用；SPM、DOM和C1-表现为直接负效应,。NO3具有最大的间接作用(0.65),其次为SPM (0.40)、DOM (0.34)。由光照强度本身引起了～67%的MMHg发生光降解反应。
2)甲基汞光降解产物与反应历程的识别
MMHg光降解反应呈一级动力学反应,主要降解产物为Hg0。光照波长和强度对MMHg光降解速率和产物有重要影响。在PAR、UV-A、UV-B、UV-C和PAR+UV-A+UV-B条件下在反应4h后,MMHg光降解速率分别为0.061h-1、0.562h-1、0.961h-1、1.221h-1和1.346h-1Hg0的释放速率分别是0.008ng min-1、0.222ng min-1、0.273ng min-1’0.220ng min-1和0.392ngmin-1。在反应器暴露于3、2、1UVA lamp条件下,MMHg光降解伪一级动力学速率常数分别为0.562、0.509、0.403h-1,Hg0的平均释放通量分别为0.222、0.207、0.166ngmin-1。黑暗条件下未发现MMHg光降解反应,也末检测到Hg0的生成。
3)氯离子对甲基汞光降解、降解产物光化学行为的影响机制
Cl-的存在对MMHg光降解反应具有明显的抑制作用。随Cl-浓度的增加(0-20mg L-1),MMHg光降解速率逐步减少。在浓度为0、0.02、0.2、2、20和200mg L-1时,MMHg的光降解速率分别为：1.35、1.00、0.92、0.45、0.34和0.37h-1。Cl-的存在情况下光照强度与波长对MMHg光降解有重要影响。在UV-C、UV-B、UV-A、自然光(NL)、PAR和黑暗条件下,MMHg光降解速率分别为0.96h-1、0.76h-1、0.29h-1、0.37h-1、0.04h-1和0；在UV-B紫外灯照射下,MMHg光降解速率随其强度的提高由0.14h-1增加至0.76h-1。
Cl-不仅对MMHg光降解反应本身有抑制作用,对其降解产物的光化学行为也有重要影响。在NL条件下,随Cl-浓度的增加(0-20mgL-1),Hg0的释放通量比对照处理(CK)减少25%-75%。在不同波长和光强度处理下,MMHg光降解产物Hg0的释放通量也具有较大的差异。由PAR、NL、UV-A、UV-B和UV-C引发的MMHg光降解产生的Hg0的释放通量分别占加入总MMHg量的比例是(100ng)：1%、23%、2%、12%和4%;随UV-B强度的增加,Hg0的释放通量分别占加入总MMHg量的比例是4%、8%和13%。
MMHg的形态是影响MMHg光降解反应的主要因素。Cl-的存在不仅影响MMHg的形态,而且影响MMHg光降解产物的形态,故Cl-表现为对MMHg光降解反应过程、降解产物的光化学行为均产生影响。在Cl-存在的情况下,Hg(Ⅱ)的光还原反应过程受到显著的影响。Hg(Ⅱ)的形态、光照条件是Cl-存在时影响Hg(Ⅱ)的光还原反应的重要因素。Cl-浓度与pH值是影响溶液中IHg形态的重要因子,因而两者的交互作用对Hg(Ⅱ)的光还原反应产生影响。除Cl-与Hg2+间的强结合力降低了溶液中活性的Hg2+的浓度以致反应速率下降外,Cl-的强氧化能力也是影响溶液中IHg氧化还原反应的重要因素,而且不同光照波段对这一过程的影响机制也有较大差异。
4)硝酸根对甲基汞光降解、汞循环的影响
在有紫外波段照射,添加NO3后MMHg光降解反应速率明显加快,Hg0的生成量极低,随NO3-浓度的升高,MMHg光降解的速率逐步增加；在PAR条件下,NO3-和BA均未对MMHg光降解速率、产物表现出影响作用。表明·OH具有促进MMHg光降解的作用,且会抑制MMHg降解产物Hg0的生成。
NO3-对水中MMHg光降解及汞循环有重要影响。上覆水、底泥和间隙水中MMHg和溶解态汞(DHg)的浓度水平在白大均出现下降的趋势,而在夜间出现浓度上升的趋势,底泥中与间隙水中MMHg的浓度与上覆水中溶解氧的浓度间存在较强的负相关关系；活性汞(RHg)在间隙水和上覆水中的浓度呈现有光照时增高、黑夜时下降的变化趋势；在有NO3的情况下加剧了此变化规律。MMHg发生光降解反应是上覆水中MMHg浓度下降的主要原因,且NO3-的存在能促进上覆水中MMHg光降解速率。NO3光降解产生的·OH是促进MMHg光降解速率提高的主要基团。
MMHg在白天和黑夜之间的扩散通量有显著的差异,夜间MMHg的扩散通量为6.04-6.92ng m-2d-1,是白天通量的1.6-2.4倍；各处理RHg的昼夜扩散速率没有显著的差异,扩散速率变化范围是3.25-3.43ngm-2d-1; DHg夜间的扩散速率为7.79-8.36ngm-2d-1,比白天的扩散速率大0.37-0.47倍。夜间MMHg是通过底泥-上覆水界面迁移的主要形态,白天RHg是主要形态,即底泥在白天期间是上覆水RHg的源,夜间是上覆水MMHg的源。
本研究确定了光照强度、悬浮颗粒物、DOM、Cl和N03-是影响三峡水库表层水体MMHg光降解的因素,定量评估了各影响因素对MMHg光降解的作用方式；给出了MMHg光降解的反应历程,即首先降解生成无机汞,然后进一步发生还原反应生成Hg0；明确了Cl-在MMHg光降解及Hg(Ⅱ)光还原过程中的作用机制,发现MMHg形态是影响其降解的主要因素,Hg(Ⅱ)的形态是控制其还原反应速率的主要原因;确定了NO3-存在情况下水体汞的循环特征。研究结果对理解三峡水库运行以后汞的环境地球化学行为提供重要数据基础,也可为理解自然水体MMHg光降解机制、降解特征提供科学依据。
Since methylmercury (MMHg) was found to be responsible for the Minamata disease in Japan in the middle of last century, mercury (Hg) pollution in the environment has been caused highly considered, then the research work of environmental geochemistry of Hg have became hotspots and priorities. New created reservoirs and flooding landscapes have an important environmental consequence of MMHg bioaccumulation because the decomposition of organic carbon in flooded soil and vegetation in reservoirs can improve the methylation rates of inorganic Hg to MMHg, which would result in the higher MMHg exposure of people depending on reservoir fisheries for food. Thus, young reservoirs are very sensitive to Hg, and hold a capacity of activating Hg. The recently completed Three Gorges Reservoir (TGR), the largest hydroelectric power plant in the world, floods a total area of630km2,350km2of which is a seasonally flooded water level fluctuating zone. Crop and/or herbaceous vegetation grow well here during during the dry period, from late February to early June. However, this zone is submerged during flooding periods, from mid August to early November. Organic matter, nitrate, and other chemicals from soil and vegetation transfer to the water column, resulting in significant changes to physical and chemical characteristics of the water column. Impoundment by the TGR dam has thus brought about many environmental concerns including eutrophication, and contamination by MMHg. So, TGR may be also very sensitive to Hg, and hold a capacity of activating Hg. However, we possess little mechanistic knowledge of biogeochemistry of MMHg in TGR.
Photo-degradation (PD) is the dominant sink of MMHg in surface waters, resulting in low MMHg level in surface waters, and limiting bioaccumulation of Hg in aquatic organisms. Comparison of MMHg PD fluxes and its effects on Hg cycling for different ecosystems suggest that rates, fluxes, and influencing factors of MMHg PD in different water systems are varied significantly. At present, research works of MMHg PD in natural water systems were mainly carried out in western countries. The environmental conditions of TGR are significantly different from the ecosystems (e.g., Lake979, Arctic Alaskan Lake, and ELA) whose MMHg PD have been extensively studied. Intuitively, MMHg PD should be important for its cycling in TGR, and solar radiation and ambient factors induced by water level fluctuation should have important effects on MMHg PD processes. However, MMHg PD processes in TGR are not clearly understood, and the influencing factors for those processes are unknown.
Previous studies have identified that many environmental factors, such as light condition, water component, etc., are involved in the PD process. MMHg PD can occur via a direct pathway by UV radiation and/or an indirect pathway mediated by·OH and1O2in surface water. PD processes could be inhibited by dissolved organic matter (DOM), increased salinity, and suspended particulate matter (SPM) through complexation of MMHg with DOM or Cl", or through influence of photo penetration. Although these studies have proposed some mechanisms of MMHg PD in surface waters, the entire suite of environmental variables affecting MMHg PD has not been fully elucidated, especially the effects of Cl-and NO3-on MMHg PD and PD products are still unclear.
From the knowledge gaps outlined above, thus, the objectives of this study were to (1) identify PD rate constants, fluxes, spatial patterns, and influencing factors of MMHg in TGR,(2) investigate the mechanism of MMHg PD with the presence of Cl-and NO3-. The results showed that:
1) Characteristics of MMHg PD in TGR
Light intensity and wavelength ranges have significant effects on MMHg PD in TGR. In water surface, the highest PD rate constants were induced by UV-B radiation, followed by UV-A, and PAR. The contribution of PD rate constants were induced by UV-B, UV-A, and PAR were17.14%-21.30%,48.57%-61.54%, and17.16%-34.29%, respecitively. Rate constants of MMHg PD of each season varied significantly were due to dramatic variation of light intensities. The highest PD rates occurred in summer, followed by spring, autumn, and winter. All PD rate constants resulting from each wavelength range decreased rapidly with water depth. UV-B, UV-A, and PAR could induce MMHg PD in water column up to10,40, and250cm, respecitively.
MMHg PD fluxes of each season varied significantly. The highest PD fluxes occurred in summer (7.46-18.15ng m-2d-1), followed by spring (3.33-8.01ng m-2d-1), autumn (1.02-2.71ng m-2d-1), and winter (0.06-0.15ng m-2d-1). MMHg PD fluxes were calculated as1.11μg m-2y-1for Fuling,2.82μg m-2y-1for Zhongxian,2.44μg m-2y-1for Fengjie. UV-B, UV-A, and PAR accounted for7.47%-18.12%,23.22%-50.58%, and32.31%-69.13%of MMHg PD in the entire water column, respectively, implying that both PAR and UV-A radiations were responsible for MMHg PD when integrated across the entire water column.
SPM, DOM, Cl-, and NO3-play a key role in affecting MMHg PD in TGR, while some heavy metal ions, such as Fe(III), Cu(II), and Mn(II), have little effects on PD rate constants. Stepwise regression analysis showed that suspended particulate matter (SPM), DOM, DO, Cl-, and NO3-are involved in PD process. Light intensity was responsible for0.916of average MMHg PD rate constants in TGR. Path analysis indicated that light intensity and NO3-had highly positive direct effects (0.83and0.22), while SPM, DOM, and Cl-had negative direct effects (-0.13,-0.11, and-0.14) on PD rate constants. NO3-had greatest indirect effect (0.65) on PD rate constants, followed by SPM (0.40) and DOM (0.34). Solar radiation alone made a～67%direct contribution towards PD rate constants.
2) MMHg PD products and reaction processes
The rate of MMHg PD is pseudo first-order with respect to MMHg concentration in the reactor, and Hg°is the end product. Light intensity and wavelength ranges have significant effects on MMHg PD processes. When the reactor exposed to PAR, UV-A, UV-B, UV-C, and PAR+UV-A+UV-B, MMHg PD rate constants were calculated to be0.061,0.562,0.961,1.221, and1.346h-1， respecitively, and the emission rates of Hg°were calculated to be0.008,0.222,0.273,0.220, and0.392ng min-1, respecitively. When the reactor exposed to3,2, and1UVA lamp(s), MMHg PD rate constants were calculated to be0.562,0.509, and0.403h-1, respecitively, and the emission rates of Hg°were calculated to be0.222,0.207, and0.166ng min-1, respecitively. While the experiments of dark, we did not observed MMHg PD and the end product of Hg°.
3) Roles of Cl-in MMHg PD processes
The presence of Cl-can block MMHg PD processes. MMHg PD rate constants decreased with the increasing of Cl-concentrations. MMHg PD rate constants were calculated to be1.35,1.00,0.92,0.45,0.34, and0.37h-1when Cl-concentrations were0,0.02,0.2,2,20, and200mg L-1. Light intensity and wavelength ranges have significant effects on MMHg PD processes in the presence of Cl-. When the reactor exposed to UV-C, UV-B, UV-A, NL, PAR, and dark, MMHg PD rate constants were calculated to be0.96,0.76,0.29,0.37,0.04, and0h-1, respecitively. PD rate constants increased (0.14-0.76h-1) with UV-B radiation intensity.
The presence of Cl-also has significant effects on the photochemical processes of the end products from MMHg PD. The emission fluxes of Hg°decreased25%-75%with the increasing of Cl-concentrations (0-20mg L-1) when the reactor exposed to NL. The emission fluxes of Hg°from MMHg PD varied significantly under different light intensity and wavelength ranges. The proportions of Hg°were1%,23%,2%,12%, and4%when the reactor exposed to PAR, NL, UV-A, UV-B, UV-C. Emission fluxes of Hg°increased (4%-13%) with UV-B radiation intensity.
MMHg species is a key factor for controling PD rate constants. The presence of Cl-not only change the species of MMHg, but also affect the species of inorganic Hg generated from MMHg PD, thus, Cl could block MMHg PD and subsequently influence the end products from PD. The presence of Cl-can significantly affect photo-reduction rate constants of Hg(Ⅱ). Hg species and light conditions are important variables that involved in photochemical reactions of Hg(Ⅱ) with Cl-. The concentrations of Cl-and pH values have significant effects on Hg species and thus affect photo-reduction processes of Hg(Ⅱ). The decreased photo-reduction rate constants are not only caused by Cl-complexation, also the presence of Cl-improved photo-oxidation of Hg(0) is the key reason for the low photo-reduction rate constants of Hg(Ⅱ) with Cl-. Moreover, this effect is highly wavelength dependent.
4) Effects of NO3-on MMHg PD and Hg cycling
Under UV radiations, NO3-can significantly improve MMHg PD rate constants, and block the emission fluxes of Hg°. While under PAR radiations, NO3-did not show this effect. Those results demonstrate that·OH can elevate MMHg PD rate constants, and inhibit the emission fluxes of Hg°.
The presence of NO3-has significant effects on MMHg PD proceses and Hg cycling in water systems. Both of concentrations of MMHg and THg in overlying water, sediment, and pore water decreased during daylight time, and increased during night. RHg concentraton increased during daylight time and decreased during dark time. The presence of NO3-increased those tendencies. Correlation anslysis shows that MMHg concentration in sediment and pore water have significant negative realtion to DO in overlying water. Photodegradation is the predominant sink of MMHg in overlying water. Photolysis of NO3-can generate·OH, which hold the capacity for impoving MMHg PD processes.
Diffusive flux of MMHg during daylight time and dark time varied significantly. The diffusive flux of MMHg is6.04-6.92ng m-2d-1for night, which is1.6-2.4times greater than that for sunlight time. There were no differences of diffusive flux of RHg during daylight time and dark time, ranging from3.25ng m-2d-1to3.43ng m-2d-1. The diffusive flux of DHg is7.79-8.36ng m-2d-1for night, which is0.37-0.47times greater than that for sunlight time. Those suggest that MMHg is the predominant species that transfer across sediment-water surface during dark time, and RHg is the predominant species that transfer across sediment-water surface during sunlight time. Thus, sediment is source of MMHg to overlying water during dark time, and is the source of RHg to overlying water during sunlight time.
This work found that light intensity, SPM, DOM, Cl-, and NO3-are the influencing factors involved in MMHg PD processes inTGR, estimated the contribution of those factors towards MMHg PD in TGR. Also, this work analysied the reacton processes of MMHg, identified the role of Cl-and NO3-in MMHg PD and Hg cycling. The results are of great importance for understanding Hg cycling characteristics in TGR after impounded. Also, the results are very important for underatanding the menchanism of MMHg PD in natural waters.
表层水中的MMHg发生光化学降解反应在水体汞的生物地球化学循环过程中占有重要地位,是水环境中MMHg去甲基化反应的主要路径,同时也是水环境中MMHg浓度维持在较低水平的重要原因。在比较不同水域MMHg光降解的速率与对区域汞循环影响时发现,不同水环境间MMHg光降解速率、对区域汞循环的影响具有较大的差异。目前,实地水环境中的MMHg光降解研究主要集中在欧美水域,而在三峡水库这种典型的水环境系统中,其水文特征与已开展MMHg光降解研究水域的有较大的差异,且MMHg的光化学行为特征仍不明了。因此,三峡水库作为典型的水生生态系统,很有必要探究MMHg在其水域的光化学行为特征及机制。
研究发现,水环境的MMHg光降解受多种因素的影响,如光照和波长是影响MMHg光降解的主要影响因素；·OH、1O2等自由基团参与或促进MMHg光降解反应过程;悬浮颗粒物、DOM、盐度等会降低MMHg的光降解反应速率；也有研究称MMHg光降解不受水体化学组成等因素的影响,仅受光照条件的影响。虽然目前关于实际水环境中的MMHg光降解行为已开展了相关的科学研究,但对于自然水体MMHg的光降解机制、路径等仍不明了,特别是氯盐、硝酸盐在MMHg光降解过程中的作用机制、对降解产物光化学行为的影响等仍不明确,且部分研究结果还存在有较大的争议。
基于MMHg光降解在水体汞迁移、转化及循环过程中的重要地位,探究新建水库水体汞生物地球化学行为的必要性及重要性,以及目前三峡水库水体MMHg的光化学行为特征、影响因素、降解机制仍不明了,本研究以三峡水库为研究对象,选择典型消落区域的涪陵、忠县和奉节作为研究地点,探究三峡水库水体MMHg光降解的速率、通量、影响因素及降解机制,考察了Cl-、N03在MMHg光降解过程中的作用机制以及对降解产物光化学行为的影响。结果发现：
1)三峡水库水体甲基汞光降解特征
光照波长与强度对三峡库区水体MMHg光降解速率具有明显的影响作用。在水体表层,由UV-B引发的MMHg光降解速率最大,其次为UV-A引发的,可见光(PAR)引发的光降解的速率较小。UV-B、UV-A和PAR对对表层水体MMHg光降解的总速率的贡献分别为17.14%-21.30%、48.57%-61.54%和17.16%-34.29%。在水体表层,由于光照强度的作用,各波段引发的MMHg光降解速率具有明显的季节差异性,其中夏季的降解速率最高,其次为春季,冬季的光降解速率最低。在每个研究地点,各波段光照引发的MMHg光降解速率均随水深度的增加而呈现逐渐减小的趋势,其中UVB波段引发的光降解速率下降趋势最大,在水深10cm处基本降为0;其次为UV-A,由该波段引发的降解速率约在水深40cm处降为0,PAR波段光波穿透能力最强,可引发水深2.5m处的MMHg发生光降解反应。
MMHg光降解通量存在较大的季节性差异(p<0.01)。夏季降解通量最大,为7.46-18.15ngm-2d-1,其次为春季(3.33-8.01ng m-2d-1),再次为秋季(1.02-2.71ng m-2d-1),冬季最小,为0.06-0.15ngm-2d-1。忠县段水域MMHg年降解通量最大,为2.92μg m-2y-1，其次为奉节段水域(2.42μgm-2y-1),最小的为涪陵段水域(1.13μgm-2y-1)。每一波段对整个水体MMHg降解通量的贡献有很大的差异,UV-B的贡献为7.47%-18.12%,UV-A的贡献为23.22%-50.58%,PAR的贡献为32.31%-69.13%。因此,对整个水体而言,UV-A和PAR对三峡水库水体MMHg光降解起关键作用。
悬浮颗粒物、DOM、C1和NO3-对库区水体MMHg光降解具有重要影响,而Fe(Ⅲ).CU(Ⅱ)、 Mn(II)等重金属离子对对库区水体MMHg光降解的影响作用甚微。逐步回归分析结果显示,光照强度、悬浮颗粒物、DOM、 Cl和NO3-是影响三峡水库表层水体MMHg光降解的因素。光照强度对回归结果贡献最大,达到91.6%,其余变量贡献8.4%。通径分析结果表明,太是光照强度与NO3-具有很高的直接正向作用；SPM、DOM和C1-表现为直接负效应,。NO3具有最大的间接作用(0.65),其次为SPM (0.40)、DOM (0.34)。由光照强度本身引起了～67%的MMHg发生光降解反应。
2)甲基汞光降解产物与反应历程的识别
MMHg光降解反应呈一级动力学反应,主要降解产物为Hg0。光照波长和强度对MMHg光降解速率和产物有重要影响。在PAR、UV-A、UV-B、UV-C和PAR+UV-A+UV-B条件下在反应4h后,MMHg光降解速率分别为0.061h-1、0.562h-1、0.961h-1、1.221h-1和1.346h-1Hg0的释放速率分别是0.008ng min-1、0.222ng min-1、0.273ng min-1’0.220ng min-1和0.392ngmin-1。在反应器暴露于3、2、1UVA lamp条件下,MMHg光降解伪一级动力学速率常数分别为0.562、0.509、0.403h-1,Hg0的平均释放通量分别为0.222、0.207、0.166ngmin-1。黑暗条件下未发现MMHg光降解反应,也末检测到Hg0的生成。
3)氯离子对甲基汞光降解、降解产物光化学行为的影响机制
Cl-的存在对MMHg光降解反应具有明显的抑制作用。随Cl-浓度的增加(0-20mg L-1),MMHg光降解速率逐步减少。在浓度为0、0.02、0.2、2、20和200mg L-1时,MMHg的光降解速率分别为：1.35、1.00、0.92、0.45、0.34和0.37h-1。Cl-的存在情况下光照强度与波长对MMHg光降解有重要影响。在UV-C、UV-B、UV-A、自然光(NL)、PAR和黑暗条件下,MMHg光降解速率分别为0.96h-1、0.76h-1、0.29h-1、0.37h-1、0.04h-1和0；在UV-B紫外灯照射下,MMHg光降解速率随其强度的提高由0.14h-1增加至0.76h-1。
Cl-不仅对MMHg光降解反应本身有抑制作用,对其降解产物的光化学行为也有重要影响。在NL条件下,随Cl-浓度的增加(0-20mgL-1),Hg0的释放通量比对照处理(CK)减少25%-75%。在不同波长和光强度处理下,MMHg光降解产物Hg0的释放通量也具有较大的差异。由PAR、NL、UV-A、UV-B和UV-C引发的MMHg光降解产生的Hg0的释放通量分别占加入总MMHg量的比例是(100ng)：1%、23%、2%、12%和4%;随UV-B强度的增加,Hg0的释放通量分别占加入总MMHg量的比例是4%、8%和13%。
MMHg的形态是影响MMHg光降解反应的主要因素。Cl-的存在不仅影响MMHg的形态,而且影响MMHg光降解产物的形态,故Cl-表现为对MMHg光降解反应过程、降解产物的光化学行为均产生影响。在Cl-存在的情况下,Hg(Ⅱ)的光还原反应过程受到显著的影响。Hg(Ⅱ)的形态、光照条件是Cl-存在时影响Hg(Ⅱ)的光还原反应的重要因素。Cl-浓度与pH值是影响溶液中IHg形态的重要因子,因而两者的交互作用对Hg(Ⅱ)的光还原反应产生影响。除Cl-与Hg2+间的强结合力降低了溶液中活性的Hg2+的浓度以致反应速率下降外,Cl-的强氧化能力也是影响溶液中IHg氧化还原反应的重要因素,而且不同光照波段对这一过程的影响机制也有较大差异。
4)硝酸根对甲基汞光降解、汞循环的影响
在有紫外波段照射,添加NO3后MMHg光降解反应速率明显加快,Hg0的生成量极低,随NO3-浓度的升高,MMHg光降解的速率逐步增加；在PAR条件下,NO3-和BA均未对MMHg光降解速率、产物表现出影响作用。表明·OH具有促进MMHg光降解的作用,且会抑制MMHg降解产物Hg0的生成。
NO3-对水中MMHg光降解及汞循环有重要影响。上覆水、底泥和间隙水中MMHg和溶解态汞(DHg)的浓度水平在白大均出现下降的趋势,而在夜间出现浓度上升的趋势,底泥中与间隙水中MMHg的浓度与上覆水中溶解氧的浓度间存在较强的负相关关系；活性汞(RHg)在间隙水和上覆水中的浓度呈现有光照时增高、黑夜时下降的变化趋势；在有NO3的情况下加剧了此变化规律。MMHg发生光降解反应是上覆水中MMHg浓度下降的主要原因,且NO3-的存在能促进上覆水中MMHg光降解速率。NO3光降解产生的·OH是促进MMHg光降解速率提高的主要基团。
MMHg在白天和黑夜之间的扩散通量有显著的差异,夜间MMHg的扩散通量为6.04-6.92ng m-2d-1,是白天通量的1.6-2.4倍；各处理RHg的昼夜扩散速率没有显著的差异,扩散速率变化范围是3.25-3.43ngm-2d-1; DHg夜间的扩散速率为7.79-8.36ngm-2d-1,比白天的扩散速率大0.37-0.47倍。夜间MMHg是通过底泥-上覆水界面迁移的主要形态,白天RHg是主要形态,即底泥在白天期间是上覆水RHg的源,夜间是上覆水MMHg的源。
本研究确定了光照强度、悬浮颗粒物、DOM、Cl和N03-是影响三峡水库表层水体MMHg光降解的因素,定量评估了各影响因素对MMHg光降解的作用方式；给出了MMHg光降解的反应历程,即首先降解生成无机汞,然后进一步发生还原反应生成Hg0；明确了Cl-在MMHg光降解及Hg(Ⅱ)光还原过程中的作用机制,发现MMHg形态是影响其降解的主要因素,Hg(Ⅱ)的形态是控制其还原反应速率的主要原因;确定了NO3-存在情况下水体汞的循环特征。研究结果对理解三峡水库运行以后汞的环境地球化学行为提供重要数据基础,也可为理解自然水体MMHg光降解机制、降解特征提供科学依据。
Since methylmercury (MMHg) was found to be responsible for the Minamata disease in Japan in the middle of last century, mercury (Hg) pollution in the environment has been caused highly considered, then the research work of environmental geochemistry of Hg have became hotspots and priorities. New created reservoirs and flooding landscapes have an important environmental consequence of MMHg bioaccumulation because the decomposition of organic carbon in flooded soil and vegetation in reservoirs can improve the methylation rates of inorganic Hg to MMHg, which would result in the higher MMHg exposure of people depending on reservoir fisheries for food. Thus, young reservoirs are very sensitive to Hg, and hold a capacity of activating Hg. The recently completed Three Gorges Reservoir (TGR), the largest hydroelectric power plant in the world, floods a total area of630km2,350km2of which is a seasonally flooded water level fluctuating zone. Crop and/or herbaceous vegetation grow well here during during the dry period, from late February to early June. However, this zone is submerged during flooding periods, from mid August to early November. Organic matter, nitrate, and other chemicals from soil and vegetation transfer to the water column, resulting in significant changes to physical and chemical characteristics of the water column. Impoundment by the TGR dam has thus brought about many environmental concerns including eutrophication, and contamination by MMHg. So, TGR may be also very sensitive to Hg, and hold a capacity of activating Hg. However, we possess little mechanistic knowledge of biogeochemistry of MMHg in TGR.
Photo-degradation (PD) is the dominant sink of MMHg in surface waters, resulting in low MMHg level in surface waters, and limiting bioaccumulation of Hg in aquatic organisms. Comparison of MMHg PD fluxes and its effects on Hg cycling for different ecosystems suggest that rates, fluxes, and influencing factors of MMHg PD in different water systems are varied significantly. At present, research works of MMHg PD in natural water systems were mainly carried out in western countries. The environmental conditions of TGR are significantly different from the ecosystems (e.g., Lake979, Arctic Alaskan Lake, and ELA) whose MMHg PD have been extensively studied. Intuitively, MMHg PD should be important for its cycling in TGR, and solar radiation and ambient factors induced by water level fluctuation should have important effects on MMHg PD processes. However, MMHg PD processes in TGR are not clearly understood, and the influencing factors for those processes are unknown.
Previous studies have identified that many environmental factors, such as light condition, water component, etc., are involved in the PD process. MMHg PD can occur via a direct pathway by UV radiation and/or an indirect pathway mediated by·OH and1O2in surface water. PD processes could be inhibited by dissolved organic matter (DOM), increased salinity, and suspended particulate matter (SPM) through complexation of MMHg with DOM or Cl", or through influence of photo penetration. Although these studies have proposed some mechanisms of MMHg PD in surface waters, the entire suite of environmental variables affecting MMHg PD has not been fully elucidated, especially the effects of Cl-and NO3-on MMHg PD and PD products are still unclear.
From the knowledge gaps outlined above, thus, the objectives of this study were to (1) identify PD rate constants, fluxes, spatial patterns, and influencing factors of MMHg in TGR,(2) investigate the mechanism of MMHg PD with the presence of Cl-and NO3-. The results showed that:
1) Characteristics of MMHg PD in TGR
Light intensity and wavelength ranges have significant effects on MMHg PD in TGR. In water surface, the highest PD rate constants were induced by UV-B radiation, followed by UV-A, and PAR. The contribution of PD rate constants were induced by UV-B, UV-A, and PAR were17.14%-21.30%,48.57%-61.54%, and17.16%-34.29%, respecitively. Rate constants of MMHg PD of each season varied significantly were due to dramatic variation of light intensities. The highest PD rates occurred in summer, followed by spring, autumn, and winter. All PD rate constants resulting from each wavelength range decreased rapidly with water depth. UV-B, UV-A, and PAR could induce MMHg PD in water column up to10,40, and250cm, respecitively.
MMHg PD fluxes of each season varied significantly. The highest PD fluxes occurred in summer (7.46-18.15ng m-2d-1), followed by spring (3.33-8.01ng m-2d-1), autumn (1.02-2.71ng m-2d-1), and winter (0.06-0.15ng m-2d-1). MMHg PD fluxes were calculated as1.11μg m-2y-1for Fuling,2.82μg m-2y-1for Zhongxian,2.44μg m-2y-1for Fengjie. UV-B, UV-A, and PAR accounted for7.47%-18.12%,23.22%-50.58%, and32.31%-69.13%of MMHg PD in the entire water column, respectively, implying that both PAR and UV-A radiations were responsible for MMHg PD when integrated across the entire water column.
SPM, DOM, Cl-, and NO3-play a key role in affecting MMHg PD in TGR, while some heavy metal ions, such as Fe(III), Cu(II), and Mn(II), have little effects on PD rate constants. Stepwise regression analysis showed that suspended particulate matter (SPM), DOM, DO, Cl-, and NO3-are involved in PD process. Light intensity was responsible for0.916of average MMHg PD rate constants in TGR. Path analysis indicated that light intensity and NO3-had highly positive direct effects (0.83and0.22), while SPM, DOM, and Cl-had negative direct effects (-0.13,-0.11, and-0.14) on PD rate constants. NO3-had greatest indirect effect (0.65) on PD rate constants, followed by SPM (0.40) and DOM (0.34). Solar radiation alone made a～67%direct contribution towards PD rate constants.
2) MMHg PD products and reaction processes
The rate of MMHg PD is pseudo first-order with respect to MMHg concentration in the reactor, and Hg°is the end product. Light intensity and wavelength ranges have significant effects on MMHg PD processes. When the reactor exposed to PAR, UV-A, UV-B, UV-C, and PAR+UV-A+UV-B, MMHg PD rate constants were calculated to be0.061,0.562,0.961,1.221, and1.346h-1， respecitively, and the emission rates of Hg°were calculated to be0.008,0.222,0.273,0.220, and0.392ng min-1, respecitively. When the reactor exposed to3,2, and1UVA lamp(s), MMHg PD rate constants were calculated to be0.562,0.509, and0.403h-1, respecitively, and the emission rates of Hg°were calculated to be0.222,0.207, and0.166ng min-1, respecitively. While the experiments of dark, we did not observed MMHg PD and the end product of Hg°.
3) Roles of Cl-in MMHg PD processes
The presence of Cl-can block MMHg PD processes. MMHg PD rate constants decreased with the increasing of Cl-concentrations. MMHg PD rate constants were calculated to be1.35,1.00,0.92,0.45,0.34, and0.37h-1when Cl-concentrations were0,0.02,0.2,2,20, and200mg L-1. Light intensity and wavelength ranges have significant effects on MMHg PD processes in the presence of Cl-. When the reactor exposed to UV-C, UV-B, UV-A, NL, PAR, and dark, MMHg PD rate constants were calculated to be0.96,0.76,0.29,0.37,0.04, and0h-1, respecitively. PD rate constants increased (0.14-0.76h-1) with UV-B radiation intensity.
The presence of Cl-also has significant effects on the photochemical processes of the end products from MMHg PD. The emission fluxes of Hg°decreased25%-75%with the increasing of Cl-concentrations (0-20mg L-1) when the reactor exposed to NL. The emission fluxes of Hg°from MMHg PD varied significantly under different light intensity and wavelength ranges. The proportions of Hg°were1%,23%,2%,12%, and4%when the reactor exposed to PAR, NL, UV-A, UV-B, UV-C. Emission fluxes of Hg°increased (4%-13%) with UV-B radiation intensity.
MMHg species is a key factor for controling PD rate constants. The presence of Cl-not only change the species of MMHg, but also affect the species of inorganic Hg generated from MMHg PD, thus, Cl could block MMHg PD and subsequently influence the end products from PD. The presence of Cl-can significantly affect photo-reduction rate constants of Hg(Ⅱ). Hg species and light conditions are important variables that involved in photochemical reactions of Hg(Ⅱ) with Cl-. The concentrations of Cl-and pH values have significant effects on Hg species and thus affect photo-reduction processes of Hg(Ⅱ). The decreased photo-reduction rate constants are not only caused by Cl-complexation, also the presence of Cl-improved photo-oxidation of Hg(0) is the key reason for the low photo-reduction rate constants of Hg(Ⅱ) with Cl-. Moreover, this effect is highly wavelength dependent.
4) Effects of NO3-on MMHg PD and Hg cycling
Under UV radiations, NO3-can significantly improve MMHg PD rate constants, and block the emission fluxes of Hg°. While under PAR radiations, NO3-did not show this effect. Those results demonstrate that·OH can elevate MMHg PD rate constants, and inhibit the emission fluxes of Hg°.
The presence of NO3-has significant effects on MMHg PD proceses and Hg cycling in water systems. Both of concentrations of MMHg and THg in overlying water, sediment, and pore water decreased during daylight time, and increased during night. RHg concentraton increased during daylight time and decreased during dark time. The presence of NO3-increased those tendencies. Correlation anslysis shows that MMHg concentration in sediment and pore water have significant negative realtion to DO in overlying water. Photodegradation is the predominant sink of MMHg in overlying water. Photolysis of NO3-can generate·OH, which hold the capacity for impoving MMHg PD processes.
Diffusive flux of MMHg during daylight time and dark time varied significantly. The diffusive flux of MMHg is6.04-6.92ng m-2d-1for night, which is1.6-2.4times greater than that for sunlight time. There were no differences of diffusive flux of RHg during daylight time and dark time, ranging from3.25ng m-2d-1to3.43ng m-2d-1. The diffusive flux of DHg is7.79-8.36ng m-2d-1for night, which is0.37-0.47times greater than that for sunlight time. Those suggest that MMHg is the predominant species that transfer across sediment-water surface during dark time, and RHg is the predominant species that transfer across sediment-water surface during sunlight time. Thus, sediment is source of MMHg to overlying water during dark time, and is the source of RHg to overlying water during sunlight time.
This work found that light intensity, SPM, DOM, Cl-, and NO3-are the influencing factors involved in MMHg PD processes inTGR, estimated the contribution of those factors towards MMHg PD in TGR. Also, this work analysied the reacton processes of MMHg, identified the role of Cl-and NO3-in MMHg PD and Hg cycling. The results are of great importance for understanding Hg cycling characteristics in TGR after impounded. Also, the results are very important for underatanding the menchanism of MMHg PD in natural waters.
引文
1. Ababneh F A, Scott S L, Al-Reasi H A, et al. Photochemical reduction and reoxidation of aqueous mercuric chloride in the presence of ferrioxalate and air. Science of the Total Environment,2006,367:831-839.
2. Abbt-Braun G, Frimmel F, Lipp P. Isolation of organic substances from aquatic and terrestrial systems-comparison of some methods. Zeitschrift fur Wasser-und Abwasser-Forschung,1991, 24:285-292.
3. Afaneh A T, Schreckenbach G, Wang F. Density functional study of substituted (-SH,-S,-OH,-Cl) hydrated ions of Hg2+. Theoretical Chemistry Accounts,2012,131:1-17.
4. Ahn M-C, Kim B, Holsen T M, et al. Factors influencing concentrations of dissolved gaseous mercury (DGM) and total mercury (TM) in an artificial reservoir. Environmental Pollution, 2010,158:347-355.
5. Aiken G R,1988. A critical evaluation of the use of macroporous resins for the isolation of aquatic humic substances:In:Frimmel, F. H., Christman, R. F. (Editors), Humic Substances and their Role in the Environment. John Wiley and Sons Ltd. Chichester, pp.15-28.
6. Akielaszek J J, Haines T A. Mercury in the muscle tissue of fish from three northern Maine lakes. Bulletin of Environmental Contamination and Toxicology,1981,27:201-208.
7. Albers J W, Kallenbach L R, Fine L J, et al. Neurological abnormalities associated with remote occupational elemental mercury exposure. Annals of Neurology,1988,24:651-659.
8. Allard B, Arsenie I. Abiotic reduction of mercury by humic substances in aquatic system—an important process for the mercury cycle. Water Air & Soil Pollution,1991,56:457-464.
9. Amyot M, Auclair J, Poissant L. In situ high temporal resolution analysis of elemental mercury in natural waters. Analytica Chimica Acta,2001,447:153-159.
10. Amyot M, Gill G A, Morel F M. Production and loss of dissolved gaseous mercury in coastal seawater. Environmental Science & Technology,1997a,31:3606-3611.
11. Amyot M, Lean D, Mierle G. Photochemical formation of volatile mercury in high Arctic lakes. Environmental Toxicology and Chemistry,1997b,16:2054-2063.
12. Amyot M, Lean D R, Poissant L, et al. Distribution and transformation of elemental mercury in the St. Lawrence River and Lake Ontario. Canadian Journal of Fisheries and Aquatic Sciences, 2000,57:155-163.
13. Amyot M, McQueen D J, Mierle G, et al. Sunlight-induced formation of dissolved gaseous mercury in lake waters. Environmental Science & Technology,1994a,28:2366-2371.
14. Amyot M, McQueen D J, Mierle G, et al. Sunlight-induced formation of dissolved gaseous mercury in lake waters. Environmental Science & Technology,1994b,28:2366-2371.
15. Amyot M, Mierle G, Lean D, et al. Effect of solar radiation on the formation of dissolved gaseous mercury in temperate lakes. Geochimica et Cosmochimica Acta,1997c,61:975-987.
16. Amyot M, Morel F M, Ariya P A. Dark oxidation of dissolved and liquid elemental mercury in aquatic environments. Environmental Science & Technology,2005,39:110-114.
17. Ariya P A, Peterson K, Snider G, et al.,2009. Mercury chemical transformations in the gas, aqueous and heterogeneous phases:state-of-the-art science and uncertainties. Mercury fate and transport in the global atmosphere. Springer, pp.459-501.
18. Axtell C D, Myers G J, Davidson P W, et al. Semiparametric modeling of age at achieving developmental milestones after prenatal exposure to methylmercury in the Seychelles child development study. Environmental Health Perspectives,1998,106:559.
19. Baeyens W a, Leermakers M. Elemental mercury concentrations and formation rates in the Scheldt estuary and the North Sea. Marine chemistry,1998,60:257-266.
20. Balcom P H, Hammerschmidt C R, Fitzgerald W F, et al. Seasonal distributions and cycling of mercury and methylmercury in the waters of New York/New Jersey Harbor Estuary. Marine chemistry,2008,109:1-17.
21. Barkay T, Kritee K, Boyd E, et al. A thermophilic bacterial origin and subsequent constraints by redox, light and salinity on the evolution of the microbial mercuric reductase. Environmental Microbiology,2010,12:2904-2917.
22. Barkay T, Miller S M, Summers A O. Bacterial mercury resistance from atoms to ecosystems. FEMS Microbiology Reviews,2003,27:355-384.
23. Barkay T, Wagner-Dobler I. Microbial transformations of mercury:potentials, challenges, and achievements in controlling mercury toxicity in the environment. Advances in Applied Microbiology,2005,57:1-52.
24. Ben-Bassat D, Mayer A. Light-Induced Hg Volatilization and 02 Evolution in Chlorella and the Effect of DCMU and Methylamine. Physiologia Plantarum,1978,42:33-38.
25. Benes P, Havlik B,1979. Speciation of mercury in natural waters. Elsevier, North-Holland Biomedical Press, Amsterdam.
26. Bergan T, Gallardo L a, Rodhe H. Mercury in the global troposphere:a three-dimensional model study. Atmospheric Environment,1999,33:1575-1585.
27. Berlin M, Carlson J, Norseth T. Dose-dependence of methylmercury metabolism:A study of distribution:Biotransformation and excretion in the squirrel monkey. Archives of Environmental Health:An International Journal,1975,30:307-313.
28. Berman M, Bartha R. Levels of chemical versus biological methylation of mercury in sediments. Bulletin of Environmental Contamination and Toxicology,1986,36:401-404.
29. Beucher C, Wong-Wah-Chung P, Richard C, et al. Dissolved gaseous mercury formation under UV irradiation of unamended tropical waters from French Guyana. Science of the Total Environment,2002,290:131-138.
30. Billen G, Joiris C, Wollast R. A bacterial methylmercury-mineralizing activity in river sediments. Water Research,1974,8:219-225.
31. Bisogni Jr J, Lawrence A W. Kinetics of mercury methylation in aerobic and anaerobic aquatic environments. Journal of Water Pollution Control Federation,1975:135-152.
32. Black F J, Poulin B A, Flegal A R. Factors controlling the abiotic photo-degradation of monomethylmercury in surface waters. Geochimica et Cosmochimica Acta,2012,84:492-507.
33. Bloom N. Determination of picogram levels of methylmercury by aqueous phase ethylation, followed by cryogenic gas chromatography with cold vapour atomic fluorescence detection. Canadian Journal of Fisheries and Aquatic Sciences,1989,46:1131-1140.
34. Bluhm R E, Bobbitt R G, Welch L W, et al. Elemental mercury vapour toxicity, treatment, and prognosis after acute, intensive exposure in chloralkali plant workers. Part I:History, neuropsychological findings and chelator effects. Human & Experimental Toxicology,1992,11: 201-210.
35. Blumthaler M, Ambach W. Indication of increasing solar ultraviolet-B radiation flux in alpine regions. Science,1990,248:206-208.
36. Bodaly R, Rudd J, Fudge R, et al. Mercury concentrations in fish related to size of remote Canadian Shield lakes. Canadian Journal of Fisheries and Aquatic Sciences,1993,50:980-987.
37. Boening D W. Ecological effects, transport, and fate of mercury:a general review. Chemosphere,2000,40:1335-1351.
38. Bowles K C, Apte S C, Maher W A, et al. Bioaccumulation and biomagnification of mercury in Lake Murray, Papua New Guinea. Canadian Journal of Fisheries and Aquatic Sciences,2001, 58:888-897.
39. Brezonik P L, Fulkerson-Brekken J. Nitrate-induced photolysis in natural waters:Controls on concentrations of hydroxyl radical photo-intermediates by natural scavenging agents. Environmental Science& Technology,1998,32:3004-3010.
40. Brunberg A-K, Blomqvist P. Quantification of anthropogenic threats to lakes in a lowland county of central Sweden. AMBIO:A Journal of the Human Environment,2001,30:127-134.
41. Burgess N M, Evers D C, Kaplan J D. Mercury and other contaminants in common loons breeding in Atlantic Canada. Ecotoxicology,2005,14:241-252.
42. Castelle S, Schafer J, Blanc G, et al. Gaseous mercury at the air-water interface of a highly turbid estuary (Gironde Estuary, France). Marine Chemistry,2009,117:42-51.
43. Celo V, Lean D R, Scott S L. Abiotic methylation of mercury in the aquatic environment. Science of the Total Environment,2006,368:126-137.
44. Chen J, Pehkonen S O, Lin C J. Degradation of monomethylmercury chloride by hydroxyl radicals in simulated natural waters. Water Research,2003,37:2496-2504.
45. Choe K Y, Gill G A, Lehman R D, et al. Sediment-water exchange of total mercury and monomethyl mercury in the San Francisco Bay-Delta. Limnology and Oceanography,2004: 1512-1527.
46. Choi H-D, Holsen T M. Gaseous mercury emissions from unsterilized and sterilized soils:the effect of temperature and UV radiation. Environmental Pollution,2009,157:1673-1678.
47. Clarkson T W. The Toxicology of Mercury. Critical reviews in clinical laboratory sciences, 1997,34:369-403.
48. Clarkson T W. Human Toxicology of Mercury. The Journal of trace elements in experimental medicine,1998,11:303-317.
49. Clarkson T W, Magos L. The toxicology of mercury and its chemical compounds. CRC Critical Reviews in Toxicology,2006,36:609-662.
50. Cossa D, Gobeil C. Mercury speciation in the lower St. Lawrence Estuary. Canadian Journal of Fisheries and Aquatic Sciences,2000,57:138-147.
51. Covelli S, Faganeli J, Horvat M, et al. Porewater distribution and benthic flux measurements of mercury and methylmercury in the Gulf of Trieste (Northern Adriatic Sea). Estuarine, Coastal and Shelf Science,1999,48:415-428.
52. Craig P J. Organometallic compounds in the environment; principles and reactions.1986:
53. Daughney C J, Siciliano S D, Rencz A N, et al. Hg (II) adsorption by bacteria:a surface complexation model and its application to shallow acidic lakes and wetlands in Kejimkujik National Park, Nova Scotia, Canada. Environmental Science & Technology,2002,36: 1546-1553.
54. Deng L, Deng N, Mou L, et al. Photo-induced transformations of Hg (II) species in the presence of Nitzschia hantzschiana, ferric ion, and humic acid. Journal of Environmental Sciences,2010, 22:76-83.
55. Deng L, Fu D, Deng N. Photo-induced transformations of mercury(II) species in the presence of algae, Chlorella vulgaris. Journal of Hazardous Materials,2009,164:798-805.
56. Deng L, Wu F, Deng N, et al. Photoreduction of mercury (II) in the presence of algae, Anabaena cylindrical. Journal of Photochemistry and Photobiology B:Biology,2008,91:117-124.
57. DeSimone R E. Methylation of mercury by common nuclear magnetic resonance reference compounds. Journal of the Chemical Society, Chemical Communications,1972:780-781.
58. Driscoll C, Blette V, Yan C, et al.,1995. The role of dissolved organic carbon in the chemistry and bioavailability of mercury in remote Adirondack lakes. Mercury as a Global Pollutant. Springer, pp.499-508.
59. Dynesius M, Nilsson C. Regulation of River Systems in the Northern Third of the World. Science,1994,266:4NOVEMBER.
60. Ebinghaus R, Wilken R-D. Transformations of mercury species in the presence of Elbe river bacteria. Applied Organometallic Chemistry,1993,7:127-135.
61. Eckley C, Watras C, Hintelmann H, et al. Mercury methylation in the hypolimnetic waters of lakes with and without connection to wetlands in northern Wisconsin. Canadian Journal of Fisheries and Aquatic Sciences,2005,62:400-411.
62. Ekstrom E B, Morel F M. Cobalt limitation of growth and mercury methylation in sulfate-reducing bacteria. Environmental Science & Technology,2007,42:93-99.
63. Ekstrom E B, Morel F M, Benoit J M. Mercury methylation independent of the acetyl-coenzyme A pathway in sulfate-reducing bacteria. Applied and Environmental Microbiology,2003,69:5414-5422.
64. EPA U. Determination of inorganic anions by ion chromatography.1993.
65. EPA U. EPA Mercury Study Report to Congress. Washington (DC):Office of Air Quality and Standards and Office of Research and Development, U.S. Environmental Protection Agency; 1997.EPA-452/R-97-009.1997.
66. EPA U,2001. Method 1630:Methyl mercury in water by distillation, aqueous ethylation, purge and trap, and CVAFS. in:Agency, U.S.E.P. (Ed.).
67. Evers D, Lane O, Savoy L, et al. Assessing the impacts of methylmercury on piscivorous wildlife using a wildlife criterion value based on the Common Loon,1998-2003. Report BRI, 2004,5:70.
68. Evers D C, Burgess N M, Champoux L, et al. Patterns and interpretation of mercury exposure in freshwater avian communities in northeastern North America. Ecotoxicology,2005,14: 193-221.
69. Falter R, Wilken R-D. Isotope experiments for the determination of the abiotic mercury methylation potential of a River Rhine sediment. Vom Wasser,1998,90:217-231.
70. Feng X, Foucher D, Hintelmann H, et al. Tracing mercury contamination sources in sediments using mercury isotope compositions. Environmental Science & Technology,2010,44: 3363-3368.
71. Fenton H. LXXIII.—Oxidation of tartaric acid in presence of iron. Journal of the Chemical Society, Transactions,1894,65:899-910.
72. Ferrara R, Mazzolai B, Lanzillotta E, et al. Volcanoes as emission sources of atmospheric mercury in the Mediterranean basin. Science of the Total Environment,2000,259:115-121.
73. Fitzgerald W, Lamborg C. Geochemistry of mercury in the environment. Treatise on Geochemistry,2003,9:107-148.
74. Fitzgerald W F, Clarkson T W. Mercury and monomethylmercury:present and future concerns. Environmental Health Perspectives,1991,96:159.
75. Fitzgerald W F, Engstrom D R, Lamborg C H, et al. Modern and historic atmospheric mercury fluxes in northern Alaska:global sources and Arctic depletion. Environmental Science & Technology,2005,39:557-568.
76. Fitzgerald W F, Lamborg C H, Hammerschmidt C R. Marine biogeochemical cycling of mercury. Chemical Reviews,2007,107:641-662.
77. Fleming E J, Mack E E, Green P G, et al. Mercury methylation from unexpected sources: molybdate-inhibited freshwater sediments and an iron-reducing bacterium. Applied and Environmental Microbiology,2006,72:457-464.
78. Fujiki M, Tajima S. The pollution of Minamata Bay by mercury. Water Science & Technology, 1992,25:133-140.
79. Gardfeldt K, Sommar J, Stromberg D, et al. Oxidation of atomic mercury by hydroxyl radicals and photoinduced decomposition of methylmercury in the aqueous phase. Atmospheric Environment,2001,35:3039-3047.
80. Garcia E, Amyot M, Ariya P A. Relationship between DOC photochemistry and mercury redox transformations in temperate lakes and wetlands. Geochimica et Cosmochimica Acta,2005a,69: 1917-1924.
81. Garcia E, Poulain A J, Amyot M, et al. Diel variations in photoinduced oxidation of Hg in freshwater. Chemosphere,2005b,59:977-981.
82. Gavis J, Ferguson J F. The cycling of mercury through the environment. Water Research,1972, 6:989-1008.
83. Gbor P K, Wen D, Meng F, et al. Modeling of mercury emission, transport and deposition in North America. Atmospheric Environment,2007,41:1135-1149.
84. Gill G A, Bloom N S, Cappellino S, et al. Sediment-water fluxes of mercury in Lavaca Bay, Texas. Environmental Science & Technology,1999,33:663-669.
85. Golding G R, Kelly C A, Sparling R, et al. Evidence for facilitated uptake of Hg (II) by Vibrio anguillarum and Escherichia coli under anaerobic and aerobic conditions. Limnology and Oceanography,2002,47:967-975.
86. Gray J E, Hines M E. Mercury:Distribution, transport, and geochemical and microbial transformations from natural and anthropogenic sources. Applied Geochemistry,2006,21: 1819-1820.
87. Grieb T M, Bowie G L, Driscoll C T, et al. Factors affecting mercury accumulation in fish in the upper Michigan peninsula. Environmental Toxicology and Chemistry,1990,9:919-930.
88. Guo H-B, Johs A, Parks J M, et al. Structure and conformational dynamics of the metalloregulator MerR upon binding of Hg (Ⅱ). Journal of molecular biology,2010,398: 555-568.
89. Gustin M S. Are mercury emissions from geologic sources significant? A status report. Science of the Total Environment,2003,304:153-167.
90. Gustin M S, Lindberg S E, Austin K, et al. Assessing the contribution of natural sources to regional atmospheric mercury budgets. Science of the Total Environment,2000,259:61-71.
91. Gustin M S, Lindberg S E, Weisberg P J. An update on the natural sources and sinks of atmospheric mercury. Applied Geochemistry,2008,23:482-493.
92. Hall B, Louis V S, Rolfhus K, et al. Impacts of reservoir creation on the biogeochemical cycling of methyl mercury and total mercury in boreal upland forests. Ecosystems,2005,8: 248-266.
93. Hammerschmidt C R, Fitzgerald W F. Photodecomposition of methylmercury in an arctic Alaskan lake. Environmental Science & Technology,2006,40:1212-1216.
94. Hammerschmidt C R, Fitzgerald W F. Iron-mediated photochemical decomposition of methylmercury in an arctic Alaskan lake. Environmental Science & Technology,2010,44: 6138-6143.
95. Hammerschmidt C R, Fitzgerald W F, Lamborg C H, et al. Biogeochemical cycling of methylmercury in lakes and tundra watersheds of Arctic Alaska. Environmental Science & Technology,2006,40:1204-1211.
96. He T, Lu J, Yang F, et al. Horizontal and vertical variability of mercury species in pore water and sediments in small lakes in Ontario. Science of the Total Environment,2007,386:53-64.
97. Heaven S, Ilyushchenko M, Tanton T, et al. Mercury in the River Nura and its floodplain, Central Kazakhstan:I. River sediments and water. Science of the Total Environment,2000,260: 35-44.
98. Hines M E, Horvat M, Faganeli J, et al. Mercury biogeochemistry in the Idrija River, Slovenia, from above the mine into the Gulf of Trieste. Environmental Research,2000,83:129-139.
99. Hines N A, Brezonik P L. Mercury dynamics in a small Northern Minnesota lake:water to air exchange and photoreactions of mercury. Marine Chemistry,2004a,90:137-149.,
100. Hines N A, Brezonik P L. Mercury dynamics in a small Northern Minnesota lake:water to air exchange and photoreactions of mercury. Marine Chemistry,2004b,90:137-149.
101. Hines N A, Brezonik P L. Mercury inputs and outputs at a small lake in northern Minnesota. Biogeochemistry,2007,84:265-284.
102. Hines N A, Brezonik P L, Engstrom D R. Sediment and porewater profiles and fluxes of mercury and methylmercury in a small seepage lake in northern Minnesota. Environmental Science & Technology,2004,38:6610-6617.
103. Hintelmann H, Wilken R-D. Levels of total mercury and methylmercury compounds in sediments of the polluted Elbe River:influence of seasonally and spatially varying environmental factors. Science of the Total Environment,1995,166:1-10.
104. Hongmei J, Xinbin F, Qianjin D. Damming effect on the distribution of mercury in Wujiang River. Chinese Journal of Geochemistry,2005,24:179-183.
105. Hope B K. An assessment of anthropogenic source impacts on mercury cycling in the Willamette Basin, Oregon, USA. Science of the Total Environment,2006,356:165-191.
106. Inoko M. Studies on the photochemical decomposition of organomercurials—methylmercury (II) chloride. Environmental Pollution Series B, Chemical and Physical,1981,2:3-10.
107. Jackson T A. Methyl mercury levels in a polluted prairie river-lake system:seasonal and site-specific variations, and the dominant influence of trophic conditions. Canadian Journal of Fisheries and Aquatic Sciences,1986,43:1873-1887.
108. Jackson T A. Biological and environmental control of mercury accumulation by fish in lakes and reservoirs of northern Manitoba, Canada. Canadian Journal of Fisheries and Aquatic Sciences,1991,48:2449-2470.
109. JENSEN S, Jernelov A. Biological methylation of mercury in aquatic organisms.1969.
110. Kehrig H d A, Malm O, Akagi H, et al. Methylmercury in fish and hair samples from the Balbina Reservoir, Brazilian Amazon. Environmental Research,1998,77:84-90.
111. Kelly C, Rudd J, Bodaly R, et al. Increases in fluxes of greenhouse gases and methyl mercury following flooding of an experimental reservoir. Environmental Science & Technology,1997, 31:1334-1344.
112. Kerin E J, Gilmour C C, Roden E, et al. Mercury methylation by dissimilatory iron-reducing bacteria. Applied and Environmental Microbiology,2006,72:7919-7921.
113. Kim D, Wang Q, Sorial G A, et al. A model approach for evaluating effects of remedial actions on mercury speciation and transport in a lake system. Science of the Total Environment,2004, 327:1-15.
114. Kirk J. Optics of UV-B radiation in natural waters. Ergebnisse der Limnologie,1994,43:1-1.
115. Kotnik J, Horvat M, Fajon V, et al. Mercury in small freshwater lakes:a case study:Lake Velenje, Slovenia. Water, Air, and Soil Pollution,2002,134:317-337.
116. Kunkely H. Horvath O, Vogler A. Photophysics and photochemistry of mercury complexes. Coordination Chemistry Reviews,1997,159:85-93.
117. Lalonde J D, Amyot M, Doyon M-R, et al. Photo-induced Hg (Ⅱ) reduction in snow from the remote and temperate Experimental Lakes Area (Ontario, Canada). Journal of Geophysical Research,2003,108:4200.
118. Lalonde J D, Amyot M, Kraepiel A M, et al. Photooxidation of Hg (0) in artificial and natural waters. Environmental Science & Technology,2001a,35:1367-1372.
119. Lalonde J D, Amyot M, Kraepiel A M L, et al. Photooxidation of Hg (0) in artificial and natural waters. Environmental Science & Technology,2001b,35:1367-1372.
120. Lalonde J D, Amyot M, Orvoine J, et al. Photoinduced oxidation of HgO (aq) in the waters from the St. Lawrence estuary. Environmental Science & Technology,2004,38:508-514.
121. Lamborg C H, Fitzgerald W F, O'Donnell J, et al. A non-steady-state compartmental model of global-scale mercury biogeochemistry with interhemispheric atmospheric gradients. Geochimica et Cosmochimica Acta,2002,66:1105-1118.
122. Lanzillotta E, Ceccarini C, Ferrara R, et al. Importance of the biogenic organic matter in photo-formation of dissolved gaseous mercury in a culture of the marine diatom Chaetoceros sp. Science of the Total Environment,2004,318:211-221.
123. Lean D. Attenuation of solar radiation in humic waters. Ecological Studies,1998a:109-124.
124. Lean D,1998b. Attenuation of solar radiation in humic waters. Aquatic Humic Substances. Springer, pp.109-124.
125. Lee X, Bullock O R, Andres R J. Anthropogenic emission of mercury to the atmosphere in the northeast United States. Geophysical Research Letters,2001,28:1231-1234.
126. Lehnherr I, St. Louis V L. Importance of ultraviolet radiation in the photodemethylation of methylmercury in freshwater ecosystems. Environmental Science & Technology,2009,43: 5692-5698.
127. Li Y, Mao Y, Liu G, et al. Degradation of methylmercury and its effects on mercury distribution and cycling in the Florida Everglades. Environmental Science & Technology,2010,44: 6661-6666.
128. Lin C-j, Pehkonen S O. Aqueous free radical chemistry of mercury in the presence of iron oxides and ambient aerosol. Atmospheric Environment,1997,31:4125-4137.
129. Lin C C, Yee N, Barkay T. Microbial transformations in the mercury cycle. Environmental Chemistry and Toxicology of Mercury,2012:155-191.
130. Lin X, Tao Y. A numerical modelling study on regional mercury budget for eastern North America. Atmospheric Chemistry and Physics,2003,3:535-548.
131. Lindberg S, Hanson P, Meyers T a, et al. Air/surface exchange of mercury vapor over forests—the need for a reassessment of continental biogenic emissions. Atmospheric Environment,1998,32:895-908.
132. Lindberg S, Turner R. Mercury emissions from chlorine-production solid waste deposits.1977:
133. Lindberg S, Turner R, Meyers T, et al. Atmospheric concentrations and deposition of Hg to A deciduous forest atwalker branch watershed, Tennessee, USA. Water Air & Soil Pollution,1991, 56:577-594.
134. Lindberg S, Zhang H, Gustin M, et al. Increases in mercury emissions from desert soils in response to rainfall and irrigation. Journal of Geophysical Research:Atmospheres (1984-2012), 1999,104:21879-21888.
135. Lindqvist O, Johansson K, Bringmark L, et al. Mercury in the Swedish environment—recent research on causes, consequences and corrective methods. Water, Air, and Soil Pollution,1991, 55:xi-261.
136. Liu G, Cai Y, O'Driscoll N, et al. Overview of Mercury in the Environment. Environmental Chemistry and Toxicology of Mercury,2012:1-12.
137. Lockwood R A, Chen K Y. Adsorption of mercury (Ⅱ) by hydrous manganese oxides. Environmental Science & Technology,1973,7:1028-1034.
138. Louchouarn P, Lucotte M, Mucci A, et al. Geochemistry of mercury in two hydroelectric reservoirs in Quebec, Canada. Canadian Journal of Fisheries and Aquatic Sciences,1993,50: 269-281.
139. Lucotte M, Schetagne R, Therien N, et al.,1999. Mercury in the biogeochemical cycle:natural environments and hydroelectric reservoirs of northern Quebec (Canada). Springer Berlin.
140. Lyons W B, Welch K A, Bonzongo J C. Mercury in aquatic systems in Antarctica. Geophysical research letters,1999,26:2235-2238.
141. Malm O. Gold mining as a source of mercury exposure in the Brazilian Amazon. Environmental Research,1998,77:73-78.
142. Maloney K O, Morris D P, Moses C O, et al. The role of iron and dissolved organic carbon in the absorption of ultraviolet radiation in humic lake water. Biogeochemistry,2005,75:393-407.
143. Mantoura R F C, Riley J. The analytical concentration of humic substances from natural waters. Analytica Chimica Acta,1975,76:97-106.
144. Marvin-Dipasquale M, Agee J, McGowan C, et al. Methyl-mercury degradation pathways:A comparison among three mercury-impacted ecosystems. Environmental Science & Technology, 2000,34:4908-4916.
145. Mason R P, Benoit J M. Organomercury compounds in the environment. Organometallic Compounds in the Environment. Wiley,2003:57-99.
146. Mason R P, Fitzgerald W F, Morel F M. The biogeochemical cycling of elemental mercury: anthropogenic influences. Geochimica et Cosmochimica Acta,1994,58:3191-3198.
147. Mason R P, Lawson N M, Lawrence A L, et al. Mercury in the Chesapeake Bay. Marine Chemistry,1999,65:77-96.
148. Mason R P, Sheu G R. Role of the ocean in the global mercury cycle. Global Biogeochemical Cycles,2002,16:40-41-40-14.
149. Matthiessen A. Reduction of divalent mercury by humic substances—kinetic and quantitative aspects. Science of the Total Environment,1998,213:177-183.
150. Meyer M. Evaluating the impact of multiple stressors on common loon population demographics—An integrated laboratory and field approach. USEPA STAR Grant R82-9085, Final Report,2006.
151. Miller C L, Mason R P, Gilmour C C, et al. Influence of dissolved organic matter on the complexation of mercury under sulfidic conditions. Environmental Toxicology and Chemistry, 2007,26:624-633.
152. Miller S M. Cleaving C-Hg bonds:two thiolates are better than one. Nature Chemical Biology, 2007,3:537-538.
153. Miskimmin B M, Rudd J W, Kelly C A. Influence of dissolved organic carbon, pH, and microbial respiration rates on mercury methylation and demethylation in lake water. Canadian Journal of Fisheries and Aquatic Sciences,1992,49:17-22.
154. Monperrus M, Tessier E, Amouroux D, et al. Mercury methylation, demethylation and reduction rates in coastal and marine surface waters of the Mediterranean Sea. Marine Chemistry,2007,107:49-63.
155. Montgomery S, Lucotte M, Rheault I. Temporal and spatial influences of flooding on dissolved mercury in boreal reservoirs. Science of the Total Environment,2000,260:147-157.
156. Mopper K, Zhou X. Hydroxyl radical photoproduction in the sea and its potential impact on marine processes. Science,1990,250:661-664.
157. Morelli E, Ferrara R, Bellini B, et al. Changes in the non-protein thiol pool and production of dissolved gaseous mercury in the marine diatom Thalassiosira weissflogii under mercury exposure. Science of the Total Environment,2009,408:286-293.
158. Morris D P, Zagarese H, Williamson C E, et al. The attenuation of solar UV radiation in lakes and the role of dissolved organic carbon. Limnology and Oceanography,1995,40:1381-1391.
159. Muresan B, Cossa D, Jezequel D, et al. The biogeochemistry of mercury at the sediment-water interface in the Thau lagoon.1. Partition and speciation. Estuarine, Coastal and Shelf Science, 2007,72:472-484.
160. Nelson J, Blair W, Brinckman F, et al. Biodegradation of phenylmercuric acetate by mercury-resistant bacteria. Applied Microbiology,1973,26:321-326.
161. Nelson P F. Atmospheric emissions of mercury from Australian point sources. Atmospheric Environment,2007,41:1717-1724.
162. Nriagu J, Becker C. Volcanic emissions of mercury to the atmosphere:global and regional inventories. Science of the Total Environment,2003,304:3-12.
163. Nriagu J O. A global assessment of natural sources of atmospheric trace metals. Nature,1989, 338:47-49.
164. Nriagu J O. Legacy of mercury pollution. Nature,1993,363:589.
165. Nriagu J O. Mechanistic steps in the photoreduction of mercury in natural waters. Science of the Total Environment,1994a,154:1-8.
166. Nriagu J O. Mercury pollution from the past mining of gold and silver in the Americas. Science of the Total Environment,1994b,149:167-181.
167. Nriagu J O, Pacyna J M. Quantitative assessment of worldwide contamination of air, water and soils by trace metals. Nature,1988,333:134-139.
168.0'Driscoll N, Lean D, Loseto L, et al. Effect of dissolved organic carbon on the photoproduction of dissolved gaseous mercury in lakes:Potential impacts of forestry. Environmental Science& Technology,2004,38:2664-2672.
169. O'Driscoll N, Poissant L, Canario J, et al. Continuous analysis of dissolved gaseous mercury and mercury volatilization in the upper St. Lawrence River:Exploring temporal relationships and UV attenuation. Environmental Science & Technology,2007,41:5342-5348.
170. O'driscoll N, Siciliano S, Lean D, et al. Gross photoreduction kinetics of mercury in temperate freshwater lakes and rivers:application to a general model of DGM dynamics. Environmental Science & Technology,2006a,40:837-843.
171. O'Driscoll N, Siciliano S, Peak D, et al. The influence of forestry activity on the structure of dissolved organic matter in lakes:Implications for mercury photoreactions. Science of the Total Environment,2006b,366:880-893.
172. O'Driscoll N J, Rencz A N, Lean D R,2005. Mercury cycling in a wetland-dominated ecosystem:a multidisciplinary study. Society of Environmental Toxicology and Chemistry (SETAC).
173. O'Driscoll N J, Rencz A, Lean D R S. The biogeochemistry and fate of mercury in the environment. Metal ions in Biological Systems,2005,43:221-238.
174. Organization W H. IPCS environmental health criteria 101:methylmercury. International programme of chemical safety. World Health Organization, Geneva, Switzerland,1990.
175. Pacyna E, Pacyna J. Global emission of mercury from anthropogenic sources in 1995. Water, Air, and Soil Pollution,2002,137:149-165.
176. Pacyna E, Pacyna J, Pirrone N. European emissions of atmospheric mercury from anthropogenic sources in 1995. Atmospheric Environment,2001,35:2987-2996.
177. Pacyna E G, Pacyna J, Sundseth K, et al. Global emission of mercury to the atmosphere from anthropogenic sources in 2005 and projections to 2020. Atmospheric Environment,2010,44: 2487-2499.
178. Pacyna E G, Pacyna J M, Fudala J, et al. Mercury emissions to the atmosphere from anthropogenic sources in Europe in 2000 and their scenarios until 2020. Science of the Total Environment,2006,370:147-156.
179. Park J-G, Curtis L. Mercury distribution in sediments and bioaccumulation by fish in two Oregon reservoirs:point-source and nonpoint-source impacted systems. Archives of Environmental Contamination and Toxicology,1997,33:423-429.
180. Parks J M, Guo H, Momany C, et al. Mechanism of Hg-C Protonolysis in the Organomercurial Lyase MerB. Journal of the American Chemical Society,2009,131:13278-13285.
181. Paterson M J, Rudd J W, St. Louis V. Increases in Total and Methylmercury in Zooplankton following Flooding of a Peatland Reservoir §. Environmental Science & Technology,1998,32: 3868-3874.
182. Pirrone N, Costa P, Pacyna J, et al. Mercury emissions to the atmosphere from natural and anthropogenic sources in the Mediterranean region. Atmospheric Environment,2001,35: 2997-3006.
183. Poissant L, Dommergue A, Ferrari C P,2002. Mercury as a global pollutant. Journal de Physique IV (Proceedings). EDP sciences, pp.143-160.
184. Porvari P. Development of fish mercury concentrations in Finnish reservoirs from 1979 to 1994. Science of the Total Environment,1998,213:279-290.
185. Poulain A, Amyot M, Findlay D, et al. Biological and photochemical production of dissolved gaseous mercury in a boreal lake. Limnology and Oceanography,2004,49:2265-2275.
186. Poulain A J, Garcia E, Amyot M, et al. Biological and chemical redox transformations of mercury in fresh and salt waters of the High Arctic during spring and summer. Environmental Science& Technology,2007,41:1883-1888.
187. Pyle D M, Mather T A. The importance of volcanic emissions for the global atmospheric mercury cycle. Atmospheric Environment,2003,37:5115-5124.
188. Qian J, Mopper K, Kieber D J. Photochemical production of the hydroxyl radical in Antarctic waters. Deep Sea Research Part Ⅰ:Oceanographic Research Papers,2001,48:741-759.
189. Quemerais B, Cossa D, Rondeau B, et al. Sources and fluxes of mercury in the St. Lawrence River. Environmental Science & Technology,1999,33:840-849.
190.Qureshi A, O'Driscoll N J, MacLeod M, et al. Photoreactions of mercury in surface ocean water: gross reaction kinetics and possible pathways. Environmental Science & Technology,2009,44: 644-649.
191.Ramlal P, Kelly C, Rudd J, et al. Sites of methyl mercury production in remote Canadian Shield. Canadian Journal of Fisheries and Aquatic Sciences,1993,50:972-979.
192. Ravichandran M. Interactions between mercury and dissolved organic matter--a review. Chemosphere,2004,55:319-331.
193. Robinson J B, Tuovinen O. Mechanisms of microbial resistance and detoxification of mercury and organomercury compounds:physiological, biochemical, and genetic analyses. Microbiological Reviews,1984,48:95.
194. Rolfhus K, Sakamoto H, Cleckner L, et al. Distribution and fluxes of total and methylmercury in Lake Superior. Environmental Science & Technology,2003,37:865-872.
195. Rolfhus K R, Lamborg C H, Fitzgerald W F, et al. Evidence for enhanced mercury reactivity in response to estuarine mixing. Journal of Geophysical Research:Oceans (1978-2012),2003, 108.
196. Schaefer J K, Morel F M. High methylation rates of mercury bound to cysteine by Geobacter sulfurreducens. Nature Geoscience,2009,2:123-126.
197. Scheuhammer A M, Meyer M W, Sandheinrich M B, et al. Effects of environmental methylmercury on the health of wild birds, mammals, and fish. AMBIO:A Journal of the Human Environment,2007,36:12-19.
198. Schroeder W, Lindqvist O, Munthe J, et al. Volatilization of mercury from lake surfaces. Science of the Total Environment,1992,125:47-66.
199.Schroeder W H, Munthe J. Atmospheric mercury-an overview. Atmospheric Environment,1998, 32:809-822.
200. Seigneur C, Karamchandani P, Lohman K, et al. Multiscale modeling of the atmospheric fate and transport of mercury. Journal of Geophysical Research:Atmospheres (1984-2012),2001, 106:27795-27809.
201. Seigneur C, Lohman K, Vijayaraghavan K, et al. Contributions of global and regional sources to mercury deposition in New York State. Environmental Pollution,2003,123:365-373.
202. Seigneur C, Vijayaraghavan K, Lohman K, et al. Global source attribution for mercury deposition in the United States. Environmental Science & Technology,2004,38:555-569.
203. Selin N E. Global biogeochemical cycling of mercury:a review. Annual Review of Environment and Resources,2009,34:43.
204. Selin N E, Jacob D J, Yantosca R M, et al. Global 3-D land-ocean-atmosphere model for mercury:Present-day versus preindustrial cycles and anthropogenic enrichment factors for deposition. Global Biogeochemical Cycles,2008,22:1-13.
205. Seller P, Kelly C, Rudd J, et al. Photodegradation of methylmercury in lakes. Nature,1996,380: 694-697.
206. Sellers P, Kelly C A, Rudd J W M. Fluxes of methylmercury to the water column of a drainage lake:The relative importance of internal and external sources. Limnology and Oceanography, 2001,46:623-631.
207. Shetty S K, Lin C-J, Streets D G, et al. Model estimate of mercury emission from natural sources in East Asia. Atmospheric Environment,2008,42:8674-8685.
208. Sheu G-R, Mason R P. An examination of the oxidation of elemental mercury in the presence of halide surfaces. Journal of Atmospheric Chemistry,2004,48:107-130.
209. Si L, Ariya P A. Reduction of Oxidized Mercury Species by Dicarboxylic Acids (C2-C4): Kinetic and Product Studies. Environmental science & technology,2008,42:5150-5155.
210. Siciliano S D, O'Driscoll N J, Lean D. Microbial reduction and oxidation of mercury in freshwater lakes. Environmental Science & Technology,2002,36:3064-3068.
211. Siciliano S D, O'Driscoll N J, Tordon R, et al. Abiotic production of methylmercury by solar radiation. Environmental Science & Technology,2005a,39:1071-1077.
212. Siciliano S D, O'Driscoll N J, Tordon R, et al. Abiotic production of methylmercury by solar radiation. Environmental Science & Technology,2005b,39:1071-1077.
213. Silver S, Phung L T. A bacterial view of the periodic table:genes and proteins for toxic inorganic ions. Journal of Industrial Microbiology and Biotechnology,2005,32:587-605.
214. Smith-Downey N V, Sunderland E M, Jacob D J. Anthropogenic impacts on global storage and emissions of mercury from terrestrial soils:Insights from a new global model. Journal of Geophysical Research:Biogeosciences (2005-2012),2010,115:1-11.
215. Spry D J, Wiener J G. Metal bioavailability and toxicity to fish in low-alkalinity lakes:a critical review. Environmental Pollution,1991,71:243-304.
216. St. Louis V L, Rudd J W, Kelly C A, et al. The rise and fall of mercury methylation in an experimental reservoir. Environmental Science & Technology,2004,38:1348-1358.
217. Stein E D, Cohen Y, Winer A M. Environmental distribution and transformation of mercury compounds. Critical Reviews in Environmental Science and Technology,1996,26:1-43.
218. Streets D G, Hao J, Wu Y, et al. Anthropogenic mercury emissions in China. Atmospheric Environment,2005,39:7789-7806.
219. Streets D G, Zhang Q, Wu Y. Projections of global mercury emissions in 2050. Environmental Science & Technology,2009,43:2983-2988.
220. Stumm W, Morgan J J,2012. Aquatic chemistry:chemical equilibria and rates in natural waters. John Wiley & Sons.
221. Sun R, Wang D, Zhang Y, et al. Photo-degradation of monomethylmercury in the presence of chloride ion. Chemosphere,2013,91:1471-1476.
222. Sunderland E M, Krabbenhoft D P, Moreau J W, et al. Mercury sources, distribution, and bioavailability in the North Pacific Ocean:Insights from data and models. Global Biogeochemical Cycles,2009,23:
223. Therriault T W, Schneider D C. Predicting change in fish mercury concentrations following reservoir impoundment. Environmental Pollution,1998,101:33-42.
224. Tossell J. Theoretical study of the photodecomposition of methyl Hg complexes. The Journal of Physical Chemistry A,1998,102:3587-3591.
225. Tremblay A, Lucotte M, Meili M, et al. Total mercury and methylmercury contents of insects from boreal lakes:ecological, spatial and temporal patterns. Water Quality Research Journal of Canada,1996a,31:851-873.
226. Tremblay A, Lucotte M, Rheault I. Methylmercury in a benthic food web of two hydroelectric reservoirs and a natural lake of northern Quebec (Canada). Water, Air, and Soil Pollution,1996b, 91:255-269.
227. Tsui M T K, Blum J D, Finlay J C, et al. Photodegradation of methylmercury in stream ecosystems. Limnology and Oceanography,2013,58:13-22.
228. Ullrich S M, Tanton T W, Abdrashitova S A. Mercury in the aquatic environment:a review of factors affecting methylation. Critical Reviews in Environmental Science and Technology,2001, 31:241-293.
229. Vandal G, Mason R, McKnight D, et al. Mercury speciation and distribution in a polar desert lake (Lake Hoare, Antarctica) and two glacial meltwater streams. Science of the Total Environment,1998,213:229-237.
230. Vandal G M, Mason R P, Fitzgerald W F. Cycling of volatile mercury in temperate lakes. Water Air & Soil Pollution,1991,56:791-803.
231. Verdon R, Brouard D, Demers C, et al. Mercury evolution (1978-1988) in fishes of the La Grande hydroelectric complex, Quebec, Canada. Water Air & Soil Pollution,1991,56: 405-417.
232. Vette A F. Photochemical influences on the air-water exchange of mercury.1998:
233. Vost E E, Amyot M, O'Driscoll N J. Photoreactions of Mercury in Aquatic Systems. Environmental Chemistry and Toxicology of Mercury,2012:193-218.
234. Wang S, Jia Y, Wang X, et al. Total mercury and monomethylmercury in water, sediments, and hydrophytes from the rivers, estuary, and bay along the Bohai Sea coast, northeastern China. Applied Geochemistry,2009,24:1702-1711.
235. Watras C J, Morrison K A, Host J S, et al. Concentration of mercury species in relationship to other site-specific factors in the surface waters of northern Wisconsin lakes. Limnology and Oceanography,1995,40:556-565.
236. Weber J H. Review of possible paths for abiotic methylation of mercury (Ⅱ) in the aquatic environment. Chemosphere,1993,26:2063-2077.
237. Whalin L, Kim E H, Mason R. Factors influencing the oxidation, reduction, methylation and demethylation of mercury species in coastal waters. Marine Chemistry,2007,107:278-294.
238. Wiatrowski H A, Ward P M, Barkay T. Novel reduction of mercury (II) by mercury-sensitive dissimilatory metal reducing bacteria. Environmental Science & Technology,2006,40: 6690-6696.
239. Widdel F, Bak F,1992. Gram-negative mesophilic sulfate-reducing bacteria. The prokaryotes. Springer, pp.3352-3378.
240. Wiener J G, Krabbenhoft D P, Heinz G H, et al. Ecotoxicology of Mercury. Handbook of ecotoxicology,2003,2:409-463.
241. Wolfe M F, Schwarzbach S, Sulaiman R A. Effects of mercury on wildlife:a comprehensive review. Environmental Toxicology and Chemistry,1998,17:146-160.
242. Wollenberg J L, Peters S C. Mercury emission from a temperate lake during autumn turnover. Science of the Total Environment,2009,407:2909-2918.
243. Wu Y, Wang S, Streets D G， et al. Trends in anthropogenic mercury emissions in China from 1995 to 2003. Environmental Science & Technology,2006,40:5312-5318.
244. Xiao Z, Munthe J, Stromberg D, et al. Photochemical behaviour of inorganic mercury compounds in aqueous solution. Mercury Pollution; Integration and Synthesis, CJ Watras and JW Huckabee (Eds.),1994:
245. Xiao Z, Stromberg D, Lindqvist O,1995. Influence of humic substances on photolysis of divalent mercury in aqueous solution. Mercury as a Global Pollutant. Springer, pp.789-798.
246. Yamamoto M. Stimulation of elemental mercury oxidation in the presence of chloride ion in aquatic environments. Chemosphere,1996,32:1217-1224.
247. Zafiriou O C, True M B. Nitrate photolysis in seawater by sunlight. Marine Chemistry,1979,8: 33-42.
248. Zepp R G, Faust B C, Hoigne J. Hydroxyl radical formation in aqueous reactions (pH 3-8) of iron (Ⅱ) with hydrogen peroxide:the photo-Fenton reaction. Environmental Science & Technology,1992,26:313-319.
249. Zepp R G, Hoigne J, Bader H. Nitrate-induced photooxidation of trace organic chemicals in water. Environmental Science & Technology,1987,21:443-450.
250. Zhang H,2006. Photochemical redox reactions of mercury. Recent Developments in Mercury Science. Springer, pp.37-79.
251. Zhang H, Lindberg S E. Sunlight and iron (Ⅲ)-induced photochemical production of dissolved gaseous mercury in freshwater. Environmental Science & Technology,2001,35:928-935.
252. Zhang L, Wong M. Environmental mercury contamination in China:sources and impacts. Environment International,2007,33:108-121.
253. Zhang T, Hsu-Kim H. Photolytic degradation of methylmercury enhanced by binding to natural organic ligands. Nature Geoscience,2010,3:473-476.
254. Zhang Y, Sun R, Ma M, et al. Study of inhibition mechanism of NO3- on photoreduction of Hg (II) in artificial water. Chemosphere,2012,87:171-176.
255.仇广乐.贵州省典型汞矿地区汞的环境地球化学研究.中国科学院地球化学研究所博十论文.北京,2005.
256.毛雯,孙荣国,王定勇,等.硝酸根对水体中甲基汞光化学降解的影响.环境科学,2013,34：2218-2224.
257.冉祥滨.三峡水库营养盐分布特征与滞留效应研究.中国海洋大学博十论文.青岛,2009.
258.白薇扬.阿哈水库中不同形态汞迁移转化规律的初步探讨.中国科学院地球化学研究所硕士论文.北京,2006.
259.朱金山.三峡库区消落带汞的形态转化与释放特征.西南大学博士论文.重庆,2012.
260.何天容.贵州红枫湖汞的生物地球化学循环.中国科学院地球化学研究所博十论文.北京,2007.
261.何天容,冯新斌,郭艳娜,等.红枫湖沉积物中汞的环境地球化学循环.环境科学,2008,29：1768-1774.
262.何天容,吴玉勇,冯新斌.富营养化对贵州红枫湖水库汞形态和分布特征的影响.湖泊科学,2010,22：208-214.
263.孟博.西南地区敏感生态系统汞的生物地球化学过程及健康风险评价.中国科学院地球化学研究所博十论文.北京,2011.
264.林年丰.医学环境地球化学.长春：吉林科技出版社,2005.
265.洪一平,叶闽,臧小平.三峡水库水体中氮磷影响研究.中国水利,2005：23-24.
266.冯新斌.水库汞的生物地球化学循环研究进展.环保科技,2011,17：1-5.
267.冯新斌,仇广乐,付学吾,等.环境汞污染.化学进展,2009,21：436457.
268.冯新斌,付学吾,商立海,等.地表自然过程排汞研究进展及展望.生态学杂志,2011,30：845-856.
269.刘凯,杨芳,冯新斌,等.贵州省普定水库水体及沉积物孔隙水中汞的含量和形态分布初步研究.矿物岩石地球化学通报,2009,28：239-247.
270.孙荣国,毛雯,马明,等.水体中甲基汞光化学降解特征研究.环境科学,2012,33：4329-4334.
271.孙阳,王里奥,袁辉.三峡水库氮磷污染贡献率估算.重庆大学学报：自然科学版,2004,27：138-141.
272.张玉涛.光照和DOM对水体中汞转化的影响机制及动力学研究.西南大学博士论文.重庆,2011.
273.赵士波,孙荣国,王定勇,等.水体汞光还原研究进展.四川环境,2013,32：148-153.
274.钱晓莉,冯新斌.贵州草海沉积物-水界面无机汞和甲基汞的扩散通量.西南大学学报：自然科学版,2011a,33：104-108.
275.阴永光,李雁宾,蔡勇,等.汞的环境光化学.环境化学,2011,1：84-91.
2. Abbt-Braun G, Frimmel F, Lipp P. Isolation of organic substances from aquatic and terrestrial systems-comparison of some methods. Zeitschrift fur Wasser-und Abwasser-Forschung,1991, 24:285-292.
3. Afaneh A T, Schreckenbach G, Wang F. Density functional study of substituted (-SH,-S,-OH,-Cl) hydrated ions of Hg2+. Theoretical Chemistry Accounts,2012,131:1-17.
4. Ahn M-C, Kim B, Holsen T M, et al. Factors influencing concentrations of dissolved gaseous mercury (DGM) and total mercury (TM) in an artificial reservoir. Environmental Pollution, 2010,158:347-355.
5. Aiken G R,1988. A critical evaluation of the use of macroporous resins for the isolation of aquatic humic substances:In:Frimmel, F. H., Christman, R. F. (Editors), Humic Substances and their Role in the Environment. John Wiley and Sons Ltd. Chichester, pp.15-28.
6. Akielaszek J J, Haines T A. Mercury in the muscle tissue of fish from three northern Maine lakes. Bulletin of Environmental Contamination and Toxicology,1981,27:201-208.
7. Albers J W, Kallenbach L R, Fine L J, et al. Neurological abnormalities associated with remote occupational elemental mercury exposure. Annals of Neurology,1988,24:651-659.
8. Allard B, Arsenie I. Abiotic reduction of mercury by humic substances in aquatic system—an important process for the mercury cycle. Water Air & Soil Pollution,1991,56:457-464.
9. Amyot M, Auclair J, Poissant L. In situ high temporal resolution analysis of elemental mercury in natural waters. Analytica Chimica Acta,2001,447:153-159.
10. Amyot M, Gill G A, Morel F M. Production and loss of dissolved gaseous mercury in coastal seawater. Environmental Science & Technology,1997a,31:3606-3611.
11. Amyot M, Lean D, Mierle G. Photochemical formation of volatile mercury in high Arctic lakes. Environmental Toxicology and Chemistry,1997b,16:2054-2063.
12. Amyot M, Lean D R, Poissant L, et al. Distribution and transformation of elemental mercury in the St. Lawrence River and Lake Ontario. Canadian Journal of Fisheries and Aquatic Sciences, 2000,57:155-163.
13. Amyot M, McQueen D J, Mierle G, et al. Sunlight-induced formation of dissolved gaseous mercury in lake waters. Environmental Science & Technology,1994a,28:2366-2371.
14. Amyot M, McQueen D J, Mierle G, et al. Sunlight-induced formation of dissolved gaseous mercury in lake waters. Environmental Science & Technology,1994b,28:2366-2371.
15. Amyot M, Mierle G, Lean D, et al. Effect of solar radiation on the formation of dissolved gaseous mercury in temperate lakes. Geochimica et Cosmochimica Acta,1997c,61:975-987.
16. Amyot M, Morel F M, Ariya P A. Dark oxidation of dissolved and liquid elemental mercury in aquatic environments. Environmental Science & Technology,2005,39:110-114.
17. Ariya P A, Peterson K, Snider G, et al.,2009. Mercury chemical transformations in the gas, aqueous and heterogeneous phases:state-of-the-art science and uncertainties. Mercury fate and transport in the global atmosphere. Springer, pp.459-501.
18. Axtell C D, Myers G J, Davidson P W, et al. Semiparametric modeling of age at achieving developmental milestones after prenatal exposure to methylmercury in the Seychelles child development study. Environmental Health Perspectives,1998,106:559.
19. Baeyens W a, Leermakers M. Elemental mercury concentrations and formation rates in the Scheldt estuary and the North Sea. Marine chemistry,1998,60:257-266.
20. Balcom P H, Hammerschmidt C R, Fitzgerald W F, et al. Seasonal distributions and cycling of mercury and methylmercury in the waters of New York/New Jersey Harbor Estuary. Marine chemistry,2008,109:1-17.
21. Barkay T, Kritee K, Boyd E, et al. A thermophilic bacterial origin and subsequent constraints by redox, light and salinity on the evolution of the microbial mercuric reductase. Environmental Microbiology,2010,12:2904-2917.
22. Barkay T, Miller S M, Summers A O. Bacterial mercury resistance from atoms to ecosystems. FEMS Microbiology Reviews,2003,27:355-384.
23. Barkay T, Wagner-Dobler I. Microbial transformations of mercury:potentials, challenges, and achievements in controlling mercury toxicity in the environment. Advances in Applied Microbiology,2005,57:1-52.
24. Ben-Bassat D, Mayer A. Light-Induced Hg Volatilization and 02 Evolution in Chlorella and the Effect of DCMU and Methylamine. Physiologia Plantarum,1978,42:33-38.
25. Benes P, Havlik B,1979. Speciation of mercury in natural waters. Elsevier, North-Holland Biomedical Press, Amsterdam.
26. Bergan T, Gallardo L a, Rodhe H. Mercury in the global troposphere:a three-dimensional model study. Atmospheric Environment,1999,33:1575-1585.
27. Berlin M, Carlson J, Norseth T. Dose-dependence of methylmercury metabolism:A study of distribution:Biotransformation and excretion in the squirrel monkey. Archives of Environmental Health:An International Journal,1975,30:307-313.
28. Berman M, Bartha R. Levels of chemical versus biological methylation of mercury in sediments. Bulletin of Environmental Contamination and Toxicology,1986,36:401-404.
29. Beucher C, Wong-Wah-Chung P, Richard C, et al. Dissolved gaseous mercury formation under UV irradiation of unamended tropical waters from French Guyana. Science of the Total Environment,2002,290:131-138.
30. Billen G, Joiris C, Wollast R. A bacterial methylmercury-mineralizing activity in river sediments. Water Research,1974,8:219-225.
31. Bisogni Jr J, Lawrence A W. Kinetics of mercury methylation in aerobic and anaerobic aquatic environments. Journal of Water Pollution Control Federation,1975:135-152.
32. Black F J, Poulin B A, Flegal A R. Factors controlling the abiotic photo-degradation of monomethylmercury in surface waters. Geochimica et Cosmochimica Acta,2012,84:492-507.
33. Bloom N. Determination of picogram levels of methylmercury by aqueous phase ethylation, followed by cryogenic gas chromatography with cold vapour atomic fluorescence detection. Canadian Journal of Fisheries and Aquatic Sciences,1989,46:1131-1140.
34. Bluhm R E, Bobbitt R G, Welch L W, et al. Elemental mercury vapour toxicity, treatment, and prognosis after acute, intensive exposure in chloralkali plant workers. Part I:History, neuropsychological findings and chelator effects. Human & Experimental Toxicology,1992,11: 201-210.
35. Blumthaler M, Ambach W. Indication of increasing solar ultraviolet-B radiation flux in alpine regions. Science,1990,248:206-208.
36. Bodaly R, Rudd J, Fudge R, et al. Mercury concentrations in fish related to size of remote Canadian Shield lakes. Canadian Journal of Fisheries and Aquatic Sciences,1993,50:980-987.
37. Boening D W. Ecological effects, transport, and fate of mercury:a general review. Chemosphere,2000,40:1335-1351.
38. Bowles K C, Apte S C, Maher W A, et al. Bioaccumulation and biomagnification of mercury in Lake Murray, Papua New Guinea. Canadian Journal of Fisheries and Aquatic Sciences,2001, 58:888-897.
39. Brezonik P L, Fulkerson-Brekken J. Nitrate-induced photolysis in natural waters:Controls on concentrations of hydroxyl radical photo-intermediates by natural scavenging agents. Environmental Science& Technology,1998,32:3004-3010.
40. Brunberg A-K, Blomqvist P. Quantification of anthropogenic threats to lakes in a lowland county of central Sweden. AMBIO:A Journal of the Human Environment,2001,30:127-134.
41. Burgess N M, Evers D C, Kaplan J D. Mercury and other contaminants in common loons breeding in Atlantic Canada. Ecotoxicology,2005,14:241-252.
42. Castelle S, Schafer J, Blanc G, et al. Gaseous mercury at the air-water interface of a highly turbid estuary (Gironde Estuary, France). Marine Chemistry,2009,117:42-51.
43. Celo V, Lean D R, Scott S L. Abiotic methylation of mercury in the aquatic environment. Science of the Total Environment,2006,368:126-137.
44. Chen J, Pehkonen S O, Lin C J. Degradation of monomethylmercury chloride by hydroxyl radicals in simulated natural waters. Water Research,2003,37:2496-2504.
45. Choe K Y, Gill G A, Lehman R D, et al. Sediment-water exchange of total mercury and monomethyl mercury in the San Francisco Bay-Delta. Limnology and Oceanography,2004: 1512-1527.
46. Choi H-D, Holsen T M. Gaseous mercury emissions from unsterilized and sterilized soils:the effect of temperature and UV radiation. Environmental Pollution,2009,157:1673-1678.
47. Clarkson T W. The Toxicology of Mercury. Critical reviews in clinical laboratory sciences, 1997,34:369-403.
48. Clarkson T W. Human Toxicology of Mercury. The Journal of trace elements in experimental medicine,1998,11:303-317.
49. Clarkson T W, Magos L. The toxicology of mercury and its chemical compounds. CRC Critical Reviews in Toxicology,2006,36:609-662.
50. Cossa D, Gobeil C. Mercury speciation in the lower St. Lawrence Estuary. Canadian Journal of Fisheries and Aquatic Sciences,2000,57:138-147.
51. Covelli S, Faganeli J, Horvat M, et al. Porewater distribution and benthic flux measurements of mercury and methylmercury in the Gulf of Trieste (Northern Adriatic Sea). Estuarine, Coastal and Shelf Science,1999,48:415-428.
52. Craig P J. Organometallic compounds in the environment; principles and reactions.1986:
53. Daughney C J, Siciliano S D, Rencz A N, et al. Hg (II) adsorption by bacteria:a surface complexation model and its application to shallow acidic lakes and wetlands in Kejimkujik National Park, Nova Scotia, Canada. Environmental Science & Technology,2002,36: 1546-1553.
54. Deng L, Deng N, Mou L, et al. Photo-induced transformations of Hg (II) species in the presence of Nitzschia hantzschiana, ferric ion, and humic acid. Journal of Environmental Sciences,2010, 22:76-83.
55. Deng L, Fu D, Deng N. Photo-induced transformations of mercury(II) species in the presence of algae, Chlorella vulgaris. Journal of Hazardous Materials,2009,164:798-805.
56. Deng L, Wu F, Deng N, et al. Photoreduction of mercury (II) in the presence of algae, Anabaena cylindrical. Journal of Photochemistry and Photobiology B:Biology,2008,91:117-124.
57. DeSimone R E. Methylation of mercury by common nuclear magnetic resonance reference compounds. Journal of the Chemical Society, Chemical Communications,1972:780-781.
58. Driscoll C, Blette V, Yan C, et al.,1995. The role of dissolved organic carbon in the chemistry and bioavailability of mercury in remote Adirondack lakes. Mercury as a Global Pollutant. Springer, pp.499-508.
59. Dynesius M, Nilsson C. Regulation of River Systems in the Northern Third of the World. Science,1994,266:4NOVEMBER.
60. Ebinghaus R, Wilken R-D. Transformations of mercury species in the presence of Elbe river bacteria. Applied Organometallic Chemistry,1993,7:127-135.
61. Eckley C, Watras C, Hintelmann H, et al. Mercury methylation in the hypolimnetic waters of lakes with and without connection to wetlands in northern Wisconsin. Canadian Journal of Fisheries and Aquatic Sciences,2005,62:400-411.
62. Ekstrom E B, Morel F M. Cobalt limitation of growth and mercury methylation in sulfate-reducing bacteria. Environmental Science & Technology,2007,42:93-99.
63. Ekstrom E B, Morel F M, Benoit J M. Mercury methylation independent of the acetyl-coenzyme A pathway in sulfate-reducing bacteria. Applied and Environmental Microbiology,2003,69:5414-5422.
64. EPA U. Determination of inorganic anions by ion chromatography.1993.
65. EPA U. EPA Mercury Study Report to Congress. Washington (DC):Office of Air Quality and Standards and Office of Research and Development, U.S. Environmental Protection Agency; 1997.EPA-452/R-97-009.1997.
66. EPA U,2001. Method 1630:Methyl mercury in water by distillation, aqueous ethylation, purge and trap, and CVAFS. in:Agency, U.S.E.P. (Ed.).
67. Evers D, Lane O, Savoy L, et al. Assessing the impacts of methylmercury on piscivorous wildlife using a wildlife criterion value based on the Common Loon,1998-2003. Report BRI, 2004,5:70.
68. Evers D C, Burgess N M, Champoux L, et al. Patterns and interpretation of mercury exposure in freshwater avian communities in northeastern North America. Ecotoxicology,2005,14: 193-221.
69. Falter R, Wilken R-D. Isotope experiments for the determination of the abiotic mercury methylation potential of a River Rhine sediment. Vom Wasser,1998,90:217-231.
70. Feng X, Foucher D, Hintelmann H, et al. Tracing mercury contamination sources in sediments using mercury isotope compositions. Environmental Science & Technology,2010,44: 3363-3368.
71. Fenton H. LXXIII.—Oxidation of tartaric acid in presence of iron. Journal of the Chemical Society, Transactions,1894,65:899-910.
72. Ferrara R, Mazzolai B, Lanzillotta E, et al. Volcanoes as emission sources of atmospheric mercury in the Mediterranean basin. Science of the Total Environment,2000,259:115-121.
73. Fitzgerald W, Lamborg C. Geochemistry of mercury in the environment. Treatise on Geochemistry,2003,9:107-148.
74. Fitzgerald W F, Clarkson T W. Mercury and monomethylmercury:present and future concerns. Environmental Health Perspectives,1991,96:159.
75. Fitzgerald W F, Engstrom D R, Lamborg C H, et al. Modern and historic atmospheric mercury fluxes in northern Alaska:global sources and Arctic depletion. Environmental Science & Technology,2005,39:557-568.
76. Fitzgerald W F, Lamborg C H, Hammerschmidt C R. Marine biogeochemical cycling of mercury. Chemical Reviews,2007,107:641-662.
77. Fleming E J, Mack E E, Green P G, et al. Mercury methylation from unexpected sources: molybdate-inhibited freshwater sediments and an iron-reducing bacterium. Applied and Environmental Microbiology,2006,72:457-464.
78. Fujiki M, Tajima S. The pollution of Minamata Bay by mercury. Water Science & Technology, 1992,25:133-140.
79. Gardfeldt K, Sommar J, Stromberg D, et al. Oxidation of atomic mercury by hydroxyl radicals and photoinduced decomposition of methylmercury in the aqueous phase. Atmospheric Environment,2001,35:3039-3047.
80. Garcia E, Amyot M, Ariya P A. Relationship between DOC photochemistry and mercury redox transformations in temperate lakes and wetlands. Geochimica et Cosmochimica Acta,2005a,69: 1917-1924.
81. Garcia E, Poulain A J, Amyot M, et al. Diel variations in photoinduced oxidation of Hg in freshwater. Chemosphere,2005b,59:977-981.
82. Gavis J, Ferguson J F. The cycling of mercury through the environment. Water Research,1972, 6:989-1008.
83. Gbor P K, Wen D, Meng F, et al. Modeling of mercury emission, transport and deposition in North America. Atmospheric Environment,2007,41:1135-1149.
84. Gill G A, Bloom N S, Cappellino S, et al. Sediment-water fluxes of mercury in Lavaca Bay, Texas. Environmental Science & Technology,1999,33:663-669.
85. Golding G R, Kelly C A, Sparling R, et al. Evidence for facilitated uptake of Hg (II) by Vibrio anguillarum and Escherichia coli under anaerobic and aerobic conditions. Limnology and Oceanography,2002,47:967-975.
86. Gray J E, Hines M E. Mercury:Distribution, transport, and geochemical and microbial transformations from natural and anthropogenic sources. Applied Geochemistry,2006,21: 1819-1820.
87. Grieb T M, Bowie G L, Driscoll C T, et al. Factors affecting mercury accumulation in fish in the upper Michigan peninsula. Environmental Toxicology and Chemistry,1990,9:919-930.
88. Guo H-B, Johs A, Parks J M, et al. Structure and conformational dynamics of the metalloregulator MerR upon binding of Hg (Ⅱ). Journal of molecular biology,2010,398: 555-568.
89. Gustin M S. Are mercury emissions from geologic sources significant? A status report. Science of the Total Environment,2003,304:153-167.
90. Gustin M S, Lindberg S E, Austin K, et al. Assessing the contribution of natural sources to regional atmospheric mercury budgets. Science of the Total Environment,2000,259:61-71.
91. Gustin M S, Lindberg S E, Weisberg P J. An update on the natural sources and sinks of atmospheric mercury. Applied Geochemistry,2008,23:482-493.
92. Hall B, Louis V S, Rolfhus K, et al. Impacts of reservoir creation on the biogeochemical cycling of methyl mercury and total mercury in boreal upland forests. Ecosystems,2005,8: 248-266.
93. Hammerschmidt C R, Fitzgerald W F. Photodecomposition of methylmercury in an arctic Alaskan lake. Environmental Science & Technology,2006,40:1212-1216.
94. Hammerschmidt C R, Fitzgerald W F. Iron-mediated photochemical decomposition of methylmercury in an arctic Alaskan lake. Environmental Science & Technology,2010,44: 6138-6143.
95. Hammerschmidt C R, Fitzgerald W F, Lamborg C H, et al. Biogeochemical cycling of methylmercury in lakes and tundra watersheds of Arctic Alaska. Environmental Science & Technology,2006,40:1204-1211.
96. He T, Lu J, Yang F, et al. Horizontal and vertical variability of mercury species in pore water and sediments in small lakes in Ontario. Science of the Total Environment,2007,386:53-64.
97. Heaven S, Ilyushchenko M, Tanton T, et al. Mercury in the River Nura and its floodplain, Central Kazakhstan:I. River sediments and water. Science of the Total Environment,2000,260: 35-44.
98. Hines M E, Horvat M, Faganeli J, et al. Mercury biogeochemistry in the Idrija River, Slovenia, from above the mine into the Gulf of Trieste. Environmental Research,2000,83:129-139.
99. Hines N A, Brezonik P L. Mercury dynamics in a small Northern Minnesota lake:water to air exchange and photoreactions of mercury. Marine Chemistry,2004a,90:137-149.,
100. Hines N A, Brezonik P L. Mercury dynamics in a small Northern Minnesota lake:water to air exchange and photoreactions of mercury. Marine Chemistry,2004b,90:137-149.
101. Hines N A, Brezonik P L. Mercury inputs and outputs at a small lake in northern Minnesota. Biogeochemistry,2007,84:265-284.
102. Hines N A, Brezonik P L, Engstrom D R. Sediment and porewater profiles and fluxes of mercury and methylmercury in a small seepage lake in northern Minnesota. Environmental Science & Technology,2004,38:6610-6617.
103. Hintelmann H, Wilken R-D. Levels of total mercury and methylmercury compounds in sediments of the polluted Elbe River:influence of seasonally and spatially varying environmental factors. Science of the Total Environment,1995,166:1-10.
104. Hongmei J, Xinbin F, Qianjin D. Damming effect on the distribution of mercury in Wujiang River. Chinese Journal of Geochemistry,2005,24:179-183.
105. Hope B K. An assessment of anthropogenic source impacts on mercury cycling in the Willamette Basin, Oregon, USA. Science of the Total Environment,2006,356:165-191.
106. Inoko M. Studies on the photochemical decomposition of organomercurials—methylmercury (II) chloride. Environmental Pollution Series B, Chemical and Physical,1981,2:3-10.
107. Jackson T A. Methyl mercury levels in a polluted prairie river-lake system:seasonal and site-specific variations, and the dominant influence of trophic conditions. Canadian Journal of Fisheries and Aquatic Sciences,1986,43:1873-1887.
108. Jackson T A. Biological and environmental control of mercury accumulation by fish in lakes and reservoirs of northern Manitoba, Canada. Canadian Journal of Fisheries and Aquatic Sciences,1991,48:2449-2470.
109. JENSEN S, Jernelov A. Biological methylation of mercury in aquatic organisms.1969.
110. Kehrig H d A, Malm O, Akagi H, et al. Methylmercury in fish and hair samples from the Balbina Reservoir, Brazilian Amazon. Environmental Research,1998,77:84-90.
111. Kelly C, Rudd J, Bodaly R, et al. Increases in fluxes of greenhouse gases and methyl mercury following flooding of an experimental reservoir. Environmental Science & Technology,1997, 31:1334-1344.
112. Kerin E J, Gilmour C C, Roden E, et al. Mercury methylation by dissimilatory iron-reducing bacteria. Applied and Environmental Microbiology,2006,72:7919-7921.
113. Kim D, Wang Q, Sorial G A, et al. A model approach for evaluating effects of remedial actions on mercury speciation and transport in a lake system. Science of the Total Environment,2004, 327:1-15.
114. Kirk J. Optics of UV-B radiation in natural waters. Ergebnisse der Limnologie,1994,43:1-1.
115. Kotnik J, Horvat M, Fajon V, et al. Mercury in small freshwater lakes:a case study:Lake Velenje, Slovenia. Water, Air, and Soil Pollution,2002,134:317-337.
116. Kunkely H. Horvath O, Vogler A. Photophysics and photochemistry of mercury complexes. Coordination Chemistry Reviews,1997,159:85-93.
117. Lalonde J D, Amyot M, Doyon M-R, et al. Photo-induced Hg (Ⅱ) reduction in snow from the remote and temperate Experimental Lakes Area (Ontario, Canada). Journal of Geophysical Research,2003,108:4200.
118. Lalonde J D, Amyot M, Kraepiel A M, et al. Photooxidation of Hg (0) in artificial and natural waters. Environmental Science & Technology,2001a,35:1367-1372.
119. Lalonde J D, Amyot M, Kraepiel A M L, et al. Photooxidation of Hg (0) in artificial and natural waters. Environmental Science & Technology,2001b,35:1367-1372.
120. Lalonde J D, Amyot M, Orvoine J, et al. Photoinduced oxidation of HgO (aq) in the waters from the St. Lawrence estuary. Environmental Science & Technology,2004,38:508-514.
121. Lamborg C H, Fitzgerald W F, O'Donnell J, et al. A non-steady-state compartmental model of global-scale mercury biogeochemistry with interhemispheric atmospheric gradients. Geochimica et Cosmochimica Acta,2002,66:1105-1118.
122. Lanzillotta E, Ceccarini C, Ferrara R, et al. Importance of the biogenic organic matter in photo-formation of dissolved gaseous mercury in a culture of the marine diatom Chaetoceros sp. Science of the Total Environment,2004,318:211-221.
123. Lean D. Attenuation of solar radiation in humic waters. Ecological Studies,1998a:109-124.
124. Lean D,1998b. Attenuation of solar radiation in humic waters. Aquatic Humic Substances. Springer, pp.109-124.
125. Lee X, Bullock O R, Andres R J. Anthropogenic emission of mercury to the atmosphere in the northeast United States. Geophysical Research Letters,2001,28:1231-1234.
126. Lehnherr I, St. Louis V L. Importance of ultraviolet radiation in the photodemethylation of methylmercury in freshwater ecosystems. Environmental Science & Technology,2009,43: 5692-5698.
127. Li Y, Mao Y, Liu G, et al. Degradation of methylmercury and its effects on mercury distribution and cycling in the Florida Everglades. Environmental Science & Technology,2010,44: 6661-6666.
128. Lin C-j, Pehkonen S O. Aqueous free radical chemistry of mercury in the presence of iron oxides and ambient aerosol. Atmospheric Environment,1997,31:4125-4137.
129. Lin C C, Yee N, Barkay T. Microbial transformations in the mercury cycle. Environmental Chemistry and Toxicology of Mercury,2012:155-191.
130. Lin X, Tao Y. A numerical modelling study on regional mercury budget for eastern North America. Atmospheric Chemistry and Physics,2003,3:535-548.
131. Lindberg S, Hanson P, Meyers T a, et al. Air/surface exchange of mercury vapor over forests—the need for a reassessment of continental biogenic emissions. Atmospheric Environment,1998,32:895-908.
132. Lindberg S, Turner R. Mercury emissions from chlorine-production solid waste deposits.1977:
133. Lindberg S, Turner R, Meyers T, et al. Atmospheric concentrations and deposition of Hg to A deciduous forest atwalker branch watershed, Tennessee, USA. Water Air & Soil Pollution,1991, 56:577-594.
134. Lindberg S, Zhang H, Gustin M, et al. Increases in mercury emissions from desert soils in response to rainfall and irrigation. Journal of Geophysical Research:Atmospheres (1984-2012), 1999,104:21879-21888.
135. Lindqvist O, Johansson K, Bringmark L, et al. Mercury in the Swedish environment—recent research on causes, consequences and corrective methods. Water, Air, and Soil Pollution,1991, 55:xi-261.
136. Liu G, Cai Y, O'Driscoll N, et al. Overview of Mercury in the Environment. Environmental Chemistry and Toxicology of Mercury,2012:1-12.
137. Lockwood R A, Chen K Y. Adsorption of mercury (Ⅱ) by hydrous manganese oxides. Environmental Science & Technology,1973,7:1028-1034.
138. Louchouarn P, Lucotte M, Mucci A, et al. Geochemistry of mercury in two hydroelectric reservoirs in Quebec, Canada. Canadian Journal of Fisheries and Aquatic Sciences,1993,50: 269-281.
139. Lucotte M, Schetagne R, Therien N, et al.,1999. Mercury in the biogeochemical cycle:natural environments and hydroelectric reservoirs of northern Quebec (Canada). Springer Berlin.
140. Lyons W B, Welch K A, Bonzongo J C. Mercury in aquatic systems in Antarctica. Geophysical research letters,1999,26:2235-2238.
141. Malm O. Gold mining as a source of mercury exposure in the Brazilian Amazon. Environmental Research,1998,77:73-78.
142. Maloney K O, Morris D P, Moses C O, et al. The role of iron and dissolved organic carbon in the absorption of ultraviolet radiation in humic lake water. Biogeochemistry,2005,75:393-407.
143. Mantoura R F C, Riley J. The analytical concentration of humic substances from natural waters. Analytica Chimica Acta,1975,76:97-106.
144. Marvin-Dipasquale M, Agee J, McGowan C, et al. Methyl-mercury degradation pathways:A comparison among three mercury-impacted ecosystems. Environmental Science & Technology, 2000,34:4908-4916.
145. Mason R P, Benoit J M. Organomercury compounds in the environment. Organometallic Compounds in the Environment. Wiley,2003:57-99.
146. Mason R P, Fitzgerald W F, Morel F M. The biogeochemical cycling of elemental mercury: anthropogenic influences. Geochimica et Cosmochimica Acta,1994,58:3191-3198.
147. Mason R P, Lawson N M, Lawrence A L, et al. Mercury in the Chesapeake Bay. Marine Chemistry,1999,65:77-96.
148. Mason R P, Sheu G R. Role of the ocean in the global mercury cycle. Global Biogeochemical Cycles,2002,16:40-41-40-14.
149. Matthiessen A. Reduction of divalent mercury by humic substances—kinetic and quantitative aspects. Science of the Total Environment,1998,213:177-183.
150. Meyer M. Evaluating the impact of multiple stressors on common loon population demographics—An integrated laboratory and field approach. USEPA STAR Grant R82-9085, Final Report,2006.
151. Miller C L, Mason R P, Gilmour C C, et al. Influence of dissolved organic matter on the complexation of mercury under sulfidic conditions. Environmental Toxicology and Chemistry, 2007,26:624-633.
152. Miller S M. Cleaving C-Hg bonds:two thiolates are better than one. Nature Chemical Biology, 2007,3:537-538.
153. Miskimmin B M, Rudd J W, Kelly C A. Influence of dissolved organic carbon, pH, and microbial respiration rates on mercury methylation and demethylation in lake water. Canadian Journal of Fisheries and Aquatic Sciences,1992,49:17-22.
154. Monperrus M, Tessier E, Amouroux D, et al. Mercury methylation, demethylation and reduction rates in coastal and marine surface waters of the Mediterranean Sea. Marine Chemistry,2007,107:49-63.
155. Montgomery S, Lucotte M, Rheault I. Temporal and spatial influences of flooding on dissolved mercury in boreal reservoirs. Science of the Total Environment,2000,260:147-157.
156. Mopper K, Zhou X. Hydroxyl radical photoproduction in the sea and its potential impact on marine processes. Science,1990,250:661-664.
157. Morelli E, Ferrara R, Bellini B, et al. Changes in the non-protein thiol pool and production of dissolved gaseous mercury in the marine diatom Thalassiosira weissflogii under mercury exposure. Science of the Total Environment,2009,408:286-293.
158. Morris D P, Zagarese H, Williamson C E, et al. The attenuation of solar UV radiation in lakes and the role of dissolved organic carbon. Limnology and Oceanography,1995,40:1381-1391.
159. Muresan B, Cossa D, Jezequel D, et al. The biogeochemistry of mercury at the sediment-water interface in the Thau lagoon.1. Partition and speciation. Estuarine, Coastal and Shelf Science, 2007,72:472-484.
160. Nelson J, Blair W, Brinckman F, et al. Biodegradation of phenylmercuric acetate by mercury-resistant bacteria. Applied Microbiology,1973,26:321-326.
161. Nelson P F. Atmospheric emissions of mercury from Australian point sources. Atmospheric Environment,2007,41:1717-1724.
162. Nriagu J, Becker C. Volcanic emissions of mercury to the atmosphere:global and regional inventories. Science of the Total Environment,2003,304:3-12.
163. Nriagu J O. A global assessment of natural sources of atmospheric trace metals. Nature,1989, 338:47-49.
164. Nriagu J O. Legacy of mercury pollution. Nature,1993,363:589.
165. Nriagu J O. Mechanistic steps in the photoreduction of mercury in natural waters. Science of the Total Environment,1994a,154:1-8.
166. Nriagu J O. Mercury pollution from the past mining of gold and silver in the Americas. Science of the Total Environment,1994b,149:167-181.
167. Nriagu J O, Pacyna J M. Quantitative assessment of worldwide contamination of air, water and soils by trace metals. Nature,1988,333:134-139.
168.0'Driscoll N, Lean D, Loseto L, et al. Effect of dissolved organic carbon on the photoproduction of dissolved gaseous mercury in lakes:Potential impacts of forestry. Environmental Science& Technology,2004,38:2664-2672.
169. O'Driscoll N, Poissant L, Canario J, et al. Continuous analysis of dissolved gaseous mercury and mercury volatilization in the upper St. Lawrence River:Exploring temporal relationships and UV attenuation. Environmental Science & Technology,2007,41:5342-5348.
170. O'driscoll N, Siciliano S, Lean D, et al. Gross photoreduction kinetics of mercury in temperate freshwater lakes and rivers:application to a general model of DGM dynamics. Environmental Science & Technology,2006a,40:837-843.
171. O'Driscoll N, Siciliano S, Peak D, et al. The influence of forestry activity on the structure of dissolved organic matter in lakes:Implications for mercury photoreactions. Science of the Total Environment,2006b,366:880-893.
172. O'Driscoll N J, Rencz A N, Lean D R,2005. Mercury cycling in a wetland-dominated ecosystem:a multidisciplinary study. Society of Environmental Toxicology and Chemistry (SETAC).
173. O'Driscoll N J, Rencz A, Lean D R S. The biogeochemistry and fate of mercury in the environment. Metal ions in Biological Systems,2005,43:221-238.
174. Organization W H. IPCS environmental health criteria 101:methylmercury. International programme of chemical safety. World Health Organization, Geneva, Switzerland,1990.
175. Pacyna E, Pacyna J. Global emission of mercury from anthropogenic sources in 1995. Water, Air, and Soil Pollution,2002,137:149-165.
176. Pacyna E, Pacyna J, Pirrone N. European emissions of atmospheric mercury from anthropogenic sources in 1995. Atmospheric Environment,2001,35:2987-2996.
177. Pacyna E G, Pacyna J, Sundseth K, et al. Global emission of mercury to the atmosphere from anthropogenic sources in 2005 and projections to 2020. Atmospheric Environment,2010,44: 2487-2499.
178. Pacyna E G, Pacyna J M, Fudala J, et al. Mercury emissions to the atmosphere from anthropogenic sources in Europe in 2000 and their scenarios until 2020. Science of the Total Environment,2006,370:147-156.
179. Park J-G, Curtis L. Mercury distribution in sediments and bioaccumulation by fish in two Oregon reservoirs:point-source and nonpoint-source impacted systems. Archives of Environmental Contamination and Toxicology,1997,33:423-429.
180. Parks J M, Guo H, Momany C, et al. Mechanism of Hg-C Protonolysis in the Organomercurial Lyase MerB. Journal of the American Chemical Society,2009,131:13278-13285.
181. Paterson M J, Rudd J W, St. Louis V. Increases in Total and Methylmercury in Zooplankton following Flooding of a Peatland Reservoir §. Environmental Science & Technology,1998,32: 3868-3874.
182. Pirrone N, Costa P, Pacyna J, et al. Mercury emissions to the atmosphere from natural and anthropogenic sources in the Mediterranean region. Atmospheric Environment,2001,35: 2997-3006.
183. Poissant L, Dommergue A, Ferrari C P,2002. Mercury as a global pollutant. Journal de Physique IV (Proceedings). EDP sciences, pp.143-160.
184. Porvari P. Development of fish mercury concentrations in Finnish reservoirs from 1979 to 1994. Science of the Total Environment,1998,213:279-290.
185. Poulain A, Amyot M, Findlay D, et al. Biological and photochemical production of dissolved gaseous mercury in a boreal lake. Limnology and Oceanography,2004,49:2265-2275.
186. Poulain A J, Garcia E, Amyot M, et al. Biological and chemical redox transformations of mercury in fresh and salt waters of the High Arctic during spring and summer. Environmental Science& Technology,2007,41:1883-1888.
187. Pyle D M, Mather T A. The importance of volcanic emissions for the global atmospheric mercury cycle. Atmospheric Environment,2003,37:5115-5124.
188. Qian J, Mopper K, Kieber D J. Photochemical production of the hydroxyl radical in Antarctic waters. Deep Sea Research Part Ⅰ:Oceanographic Research Papers,2001,48:741-759.
189. Quemerais B, Cossa D, Rondeau B, et al. Sources and fluxes of mercury in the St. Lawrence River. Environmental Science & Technology,1999,33:840-849.
190.Qureshi A, O'Driscoll N J, MacLeod M, et al. Photoreactions of mercury in surface ocean water: gross reaction kinetics and possible pathways. Environmental Science & Technology,2009,44: 644-649.
191.Ramlal P, Kelly C, Rudd J, et al. Sites of methyl mercury production in remote Canadian Shield. Canadian Journal of Fisheries and Aquatic Sciences,1993,50:972-979.
192. Ravichandran M. Interactions between mercury and dissolved organic matter--a review. Chemosphere,2004,55:319-331.
193. Robinson J B, Tuovinen O. Mechanisms of microbial resistance and detoxification of mercury and organomercury compounds:physiological, biochemical, and genetic analyses. Microbiological Reviews,1984,48:95.
194. Rolfhus K, Sakamoto H, Cleckner L, et al. Distribution and fluxes of total and methylmercury in Lake Superior. Environmental Science & Technology,2003,37:865-872.
195. Rolfhus K R, Lamborg C H, Fitzgerald W F, et al. Evidence for enhanced mercury reactivity in response to estuarine mixing. Journal of Geophysical Research:Oceans (1978-2012),2003, 108.
196. Schaefer J K, Morel F M. High methylation rates of mercury bound to cysteine by Geobacter sulfurreducens. Nature Geoscience,2009,2:123-126.
197. Scheuhammer A M, Meyer M W, Sandheinrich M B, et al. Effects of environmental methylmercury on the health of wild birds, mammals, and fish. AMBIO:A Journal of the Human Environment,2007,36:12-19.
198. Schroeder W, Lindqvist O, Munthe J, et al. Volatilization of mercury from lake surfaces. Science of the Total Environment,1992,125:47-66.
199.Schroeder W H, Munthe J. Atmospheric mercury-an overview. Atmospheric Environment,1998, 32:809-822.
200. Seigneur C, Karamchandani P, Lohman K, et al. Multiscale modeling of the atmospheric fate and transport of mercury. Journal of Geophysical Research:Atmospheres (1984-2012),2001, 106:27795-27809.
201. Seigneur C, Lohman K, Vijayaraghavan K, et al. Contributions of global and regional sources to mercury deposition in New York State. Environmental Pollution,2003,123:365-373.
202. Seigneur C, Vijayaraghavan K, Lohman K, et al. Global source attribution for mercury deposition in the United States. Environmental Science & Technology,2004,38:555-569.
203. Selin N E. Global biogeochemical cycling of mercury:a review. Annual Review of Environment and Resources,2009,34:43.
204. Selin N E, Jacob D J, Yantosca R M, et al. Global 3-D land-ocean-atmosphere model for mercury:Present-day versus preindustrial cycles and anthropogenic enrichment factors for deposition. Global Biogeochemical Cycles,2008,22:1-13.
205. Seller P, Kelly C, Rudd J, et al. Photodegradation of methylmercury in lakes. Nature,1996,380: 694-697.
206. Sellers P, Kelly C A, Rudd J W M. Fluxes of methylmercury to the water column of a drainage lake:The relative importance of internal and external sources. Limnology and Oceanography, 2001,46:623-631.
207. Shetty S K, Lin C-J, Streets D G, et al. Model estimate of mercury emission from natural sources in East Asia. Atmospheric Environment,2008,42:8674-8685.
208. Sheu G-R, Mason R P. An examination of the oxidation of elemental mercury in the presence of halide surfaces. Journal of Atmospheric Chemistry,2004,48:107-130.
209. Si L, Ariya P A. Reduction of Oxidized Mercury Species by Dicarboxylic Acids (C2-C4): Kinetic and Product Studies. Environmental science & technology,2008,42:5150-5155.
210. Siciliano S D, O'Driscoll N J, Lean D. Microbial reduction and oxidation of mercury in freshwater lakes. Environmental Science & Technology,2002,36:3064-3068.
211. Siciliano S D, O'Driscoll N J, Tordon R, et al. Abiotic production of methylmercury by solar radiation. Environmental Science & Technology,2005a,39:1071-1077.
212. Siciliano S D, O'Driscoll N J, Tordon R, et al. Abiotic production of methylmercury by solar radiation. Environmental Science & Technology,2005b,39:1071-1077.
213. Silver S, Phung L T. A bacterial view of the periodic table:genes and proteins for toxic inorganic ions. Journal of Industrial Microbiology and Biotechnology,2005,32:587-605.
214. Smith-Downey N V, Sunderland E M, Jacob D J. Anthropogenic impacts on global storage and emissions of mercury from terrestrial soils:Insights from a new global model. Journal of Geophysical Research:Biogeosciences (2005-2012),2010,115:1-11.
215. Spry D J, Wiener J G. Metal bioavailability and toxicity to fish in low-alkalinity lakes:a critical review. Environmental Pollution,1991,71:243-304.
216. St. Louis V L, Rudd J W, Kelly C A, et al. The rise and fall of mercury methylation in an experimental reservoir. Environmental Science & Technology,2004,38:1348-1358.
217. Stein E D, Cohen Y, Winer A M. Environmental distribution and transformation of mercury compounds. Critical Reviews in Environmental Science and Technology,1996,26:1-43.
218. Streets D G, Hao J, Wu Y, et al. Anthropogenic mercury emissions in China. Atmospheric Environment,2005,39:7789-7806.
219. Streets D G, Zhang Q, Wu Y. Projections of global mercury emissions in 2050. Environmental Science & Technology,2009,43:2983-2988.
220. Stumm W, Morgan J J,2012. Aquatic chemistry:chemical equilibria and rates in natural waters. John Wiley & Sons.
221. Sun R, Wang D, Zhang Y, et al. Photo-degradation of monomethylmercury in the presence of chloride ion. Chemosphere,2013,91:1471-1476.
222. Sunderland E M, Krabbenhoft D P, Moreau J W, et al. Mercury sources, distribution, and bioavailability in the North Pacific Ocean:Insights from data and models. Global Biogeochemical Cycles,2009,23:
223. Therriault T W, Schneider D C. Predicting change in fish mercury concentrations following reservoir impoundment. Environmental Pollution,1998,101:33-42.
224. Tossell J. Theoretical study of the photodecomposition of methyl Hg complexes. The Journal of Physical Chemistry A,1998,102:3587-3591.
225. Tremblay A, Lucotte M, Meili M, et al. Total mercury and methylmercury contents of insects from boreal lakes:ecological, spatial and temporal patterns. Water Quality Research Journal of Canada,1996a,31:851-873.
226. Tremblay A, Lucotte M, Rheault I. Methylmercury in a benthic food web of two hydroelectric reservoirs and a natural lake of northern Quebec (Canada). Water, Air, and Soil Pollution,1996b, 91:255-269.
227. Tsui M T K, Blum J D, Finlay J C, et al. Photodegradation of methylmercury in stream ecosystems. Limnology and Oceanography,2013,58:13-22.
228. Ullrich S M, Tanton T W, Abdrashitova S A. Mercury in the aquatic environment:a review of factors affecting methylation. Critical Reviews in Environmental Science and Technology,2001, 31:241-293.
229. Vandal G, Mason R, McKnight D, et al. Mercury speciation and distribution in a polar desert lake (Lake Hoare, Antarctica) and two glacial meltwater streams. Science of the Total Environment,1998,213:229-237.
230. Vandal G M, Mason R P, Fitzgerald W F. Cycling of volatile mercury in temperate lakes. Water Air & Soil Pollution,1991,56:791-803.
231. Verdon R, Brouard D, Demers C, et al. Mercury evolution (1978-1988) in fishes of the La Grande hydroelectric complex, Quebec, Canada. Water Air & Soil Pollution,1991,56: 405-417.
232. Vette A F. Photochemical influences on the air-water exchange of mercury.1998:
233. Vost E E, Amyot M, O'Driscoll N J. Photoreactions of Mercury in Aquatic Systems. Environmental Chemistry and Toxicology of Mercury,2012:193-218.
234. Wang S, Jia Y, Wang X, et al. Total mercury and monomethylmercury in water, sediments, and hydrophytes from the rivers, estuary, and bay along the Bohai Sea coast, northeastern China. Applied Geochemistry,2009,24:1702-1711.
235. Watras C J, Morrison K A, Host J S, et al. Concentration of mercury species in relationship to other site-specific factors in the surface waters of northern Wisconsin lakes. Limnology and Oceanography,1995,40:556-565.
236. Weber J H. Review of possible paths for abiotic methylation of mercury (Ⅱ) in the aquatic environment. Chemosphere,1993,26:2063-2077.
237. Whalin L, Kim E H, Mason R. Factors influencing the oxidation, reduction, methylation and demethylation of mercury species in coastal waters. Marine Chemistry,2007,107:278-294.
238. Wiatrowski H A, Ward P M, Barkay T. Novel reduction of mercury (II) by mercury-sensitive dissimilatory metal reducing bacteria. Environmental Science & Technology,2006,40: 6690-6696.
239. Widdel F, Bak F,1992. Gram-negative mesophilic sulfate-reducing bacteria. The prokaryotes. Springer, pp.3352-3378.
240. Wiener J G, Krabbenhoft D P, Heinz G H, et al. Ecotoxicology of Mercury. Handbook of ecotoxicology,2003,2:409-463.
241. Wolfe M F, Schwarzbach S, Sulaiman R A. Effects of mercury on wildlife:a comprehensive review. Environmental Toxicology and Chemistry,1998,17:146-160.
242. Wollenberg J L, Peters S C. Mercury emission from a temperate lake during autumn turnover. Science of the Total Environment,2009,407:2909-2918.
243. Wu Y, Wang S, Streets D G， et al. Trends in anthropogenic mercury emissions in China from 1995 to 2003. Environmental Science & Technology,2006,40:5312-5318.
244. Xiao Z, Munthe J, Stromberg D, et al. Photochemical behaviour of inorganic mercury compounds in aqueous solution. Mercury Pollution; Integration and Synthesis, CJ Watras and JW Huckabee (Eds.),1994:
245. Xiao Z, Stromberg D, Lindqvist O,1995. Influence of humic substances on photolysis of divalent mercury in aqueous solution. Mercury as a Global Pollutant. Springer, pp.789-798.
246. Yamamoto M. Stimulation of elemental mercury oxidation in the presence of chloride ion in aquatic environments. Chemosphere,1996,32:1217-1224.
247. Zafiriou O C, True M B. Nitrate photolysis in seawater by sunlight. Marine Chemistry,1979,8: 33-42.
248. Zepp R G, Faust B C, Hoigne J. Hydroxyl radical formation in aqueous reactions (pH 3-8) of iron (Ⅱ) with hydrogen peroxide:the photo-Fenton reaction. Environmental Science & Technology,1992,26:313-319.
249. Zepp R G, Hoigne J, Bader H. Nitrate-induced photooxidation of trace organic chemicals in water. Environmental Science & Technology,1987,21:443-450.
250. Zhang H,2006. Photochemical redox reactions of mercury. Recent Developments in Mercury Science. Springer, pp.37-79.
251. Zhang H, Lindberg S E. Sunlight and iron (Ⅲ)-induced photochemical production of dissolved gaseous mercury in freshwater. Environmental Science & Technology,2001,35:928-935.
252. Zhang L, Wong M. Environmental mercury contamination in China:sources and impacts. Environment International,2007,33:108-121.
253. Zhang T, Hsu-Kim H. Photolytic degradation of methylmercury enhanced by binding to natural organic ligands. Nature Geoscience,2010,3:473-476.
254. Zhang Y, Sun R, Ma M, et al. Study of inhibition mechanism of NO3- on photoreduction of Hg (II) in artificial water. Chemosphere,2012,87:171-176.
255.仇广乐.贵州省典型汞矿地区汞的环境地球化学研究.中国科学院地球化学研究所博十论文.北京,2005.
256.毛雯,孙荣国,王定勇,等.硝酸根对水体中甲基汞光化学降解的影响.环境科学,2013,34：2218-2224.
257.冉祥滨.三峡水库营养盐分布特征与滞留效应研究.中国海洋大学博十论文.青岛,2009.
258.白薇扬.阿哈水库中不同形态汞迁移转化规律的初步探讨.中国科学院地球化学研究所硕士论文.北京,2006.
259.朱金山.三峡库区消落带汞的形态转化与释放特征.西南大学博士论文.重庆,2012.
260.何天容.贵州红枫湖汞的生物地球化学循环.中国科学院地球化学研究所博十论文.北京,2007.
261.何天容,冯新斌,郭艳娜,等.红枫湖沉积物中汞的环境地球化学循环.环境科学,2008,29：1768-1774.
262.何天容,吴玉勇,冯新斌.富营养化对贵州红枫湖水库汞形态和分布特征的影响.湖泊科学,2010,22：208-214.
263.孟博.西南地区敏感生态系统汞的生物地球化学过程及健康风险评价.中国科学院地球化学研究所博十论文.北京,2011.
264.林年丰.医学环境地球化学.长春：吉林科技出版社,2005.
265.洪一平,叶闽,臧小平.三峡水库水体中氮磷影响研究.中国水利,2005：23-24.
266.冯新斌.水库汞的生物地球化学循环研究进展.环保科技,2011,17：1-5.
267.冯新斌,仇广乐,付学吾,等.环境汞污染.化学进展,2009,21：436457.
268.冯新斌,付学吾,商立海,等.地表自然过程排汞研究进展及展望.生态学杂志,2011,30：845-856.
269.刘凯,杨芳,冯新斌,等.贵州省普定水库水体及沉积物孔隙水中汞的含量和形态分布初步研究.矿物岩石地球化学通报,2009,28：239-247.
270.孙荣国,毛雯,马明,等.水体中甲基汞光化学降解特征研究.环境科学,2012,33：4329-4334.
271.孙阳,王里奥,袁辉.三峡水库氮磷污染贡献率估算.重庆大学学报：自然科学版,2004,27：138-141.
272.张玉涛.光照和DOM对水体中汞转化的影响机制及动力学研究.西南大学博士论文.重庆,2011.
273.赵士波,孙荣国,王定勇,等.水体汞光还原研究进展.四川环境,2013,32：148-153.
274.钱晓莉,冯新斌.贵州草海沉积物-水界面无机汞和甲基汞的扩散通量.西南大学学报：自然科学版,2011a,33：104-108.
275.阴永光,李雁宾,蔡勇,等.汞的环境光化学.环境化学,2011,1：84-91.
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