三峡库区沉积物中镍污染特征评价
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摘要
截至2017年10月,三峡库区已连续第8年实现175 m蓄水目标.为了研究三峡库区在175 m运行条件下,基于不同水文情势Ni的时空变化,探求水库调度运行对库区内Ni含量的影响,并建立库区水环境中Ni元素污染评价体系.于2015年12月至2017年6月连续4个水期采集水体表层沉积物共173个,利用电感耦合等离子体质谱仪(ICP-MS)测定了沉积物中的Ni含量,发现三峡库区4个水期沉积物中Ni的平均含量均高于长江流域沉积物背景值和土壤背景值;从空间变化看,干流Ni含量从上游至下游呈增加趋势,支流Ni含量高于干流,且下游支流的Ni含量明显高于上、中游;从时间变化看,在175 m运行条件下,Ni含量较为稳定,且有降低的趋势,此外沉积物中Ni含量并未因枯、丰水期的影响而产生明显变化;同时建立了三峡库区Ni的地球化学基线模型,连续4个水期沉积物中Ni的基线值分别为47. 0、44. 2、42. 9和41. 9 mg·kg~(-1),位于中、下游的干、支流Ni含量明显受到人类活动的影响;分别以Ni的全球背景值,长江沉积物背景值和地球化学基线值为参考值进行污染评价对比,采用地积累指数法研究发现,三峡库区水环境除干流沿岸的丰都县和秭归县归州镇附近存在Ni的无至中度污染,其余均不存在污染;采用潜在生态风险评价方法发现Ni含量存在轻微潜在生态危害.采用地球化学基线值为参考比采用全球背景值和长江沉积物背景值得到的评价结果更科学,更能适应不同地域的时空变化.
The Three Gorges Reservoir(TGR) has achieved the target of water storage of 175 m for eight consecutive years until October 2017. To study the temporal and spatial variation of nickel(Ni) in different water periods under 175 m operating conditions in the TGR area,probe the impact of a large-scale water conservancy project on the Ni enrichment,and establish the pollution evaluation system of Ni in the TGR area,we collected 173 surface sediment samples from the TGR area during four consecutive water periods from December 2015 to June 2017 and measured the Ni concentration by using inductively coupled plasma mass spectrometry(ICP-MS).The mean values of Ni in the four water periods are higher than the background value of Yangtze sediment and soil. At the spatial scale,the Ni content in the mainstream exhibits a clear upward trend from upstream to downstream and is lower than that of the tributary. The tributaries of the lower reaches shows a notably higher Ni content than the tributaries of the upper and middle reaches.At the temporal scale,the water period exerts an insignificant effect on the Ni content. The Ni content is relatively stable and shows a downward tendency at a 175 m water level. The regional geochemical baseline(RGB) value of Ni was obtained through building a geochemical baseline model in the area. The RGB values of Ni in sediments during four consecutive water periods are 47. 0,44. 2,42. 9,and 41. 9 mg·kg~(-1),respectively. The Ni contents in the middle and lower reaches of the mainstream and tributary are significantly affected by human activities. Moreover,the pollution evaluations based on global Ni background values,local background values,and geochemical baseline values as reference values were compared and the geoaccumulation index and potential ecological risk of Ni were determined to comprehensively assess its pollution risk. The assessment data indicate that Ni in the aquatic environment of the TGR area is almost uncontaminated and poses a low ecological risk,except for samples in regions around Fengdu County and Guizhou Town in the Zigui County along the mainstream,which were uncontaminated to moderately contaminated. Relative to global and regional background values,the pollution assessment results obtained using the RGB as a reference value are more scientific and better match the temporal and spatial variation of the study area.
The Three Gorges Reservoir(TGR) has achieved the target of water storage of 175 m for eight consecutive years until October 2017. To study the temporal and spatial variation of nickel(Ni) in different water periods under 175 m operating conditions in the TGR area,probe the impact of a large-scale water conservancy project on the Ni enrichment,and establish the pollution evaluation system of Ni in the TGR area,we collected 173 surface sediment samples from the TGR area during four consecutive water periods from December 2015 to June 2017 and measured the Ni concentration by using inductively coupled plasma mass spectrometry(ICP-MS).The mean values of Ni in the four water periods are higher than the background value of Yangtze sediment and soil. At the spatial scale,the Ni content in the mainstream exhibits a clear upward trend from upstream to downstream and is lower than that of the tributary. The tributaries of the lower reaches shows a notably higher Ni content than the tributaries of the upper and middle reaches.At the temporal scale,the water period exerts an insignificant effect on the Ni content. The Ni content is relatively stable and shows a downward tendency at a 175 m water level. The regional geochemical baseline(RGB) value of Ni was obtained through building a geochemical baseline model in the area. The RGB values of Ni in sediments during four consecutive water periods are 47. 0,44. 2,42. 9,and 41. 9 mg·kg~(-1),respectively. The Ni contents in the middle and lower reaches of the mainstream and tributary are significantly affected by human activities. Moreover,the pollution evaluations based on global Ni background values,local background values,and geochemical baseline values as reference values were compared and the geoaccumulation index and potential ecological risk of Ni were determined to comprehensively assess its pollution risk. The assessment data indicate that Ni in the aquatic environment of the TGR area is almost uncontaminated and poses a low ecological risk,except for samples in regions around Fengdu County and Guizhou Town in the Zigui County along the mainstream,which were uncontaminated to moderately contaminated. Relative to global and regional background values,the pollution assessment results obtained using the RGB as a reference value are more scientific and better match the temporal and spatial variation of the study area.
引文
[1]杨明.大宝山矿区重金属元素(Zn,Ni,Cr)和氟环境地球化学效应研究[D].广州:华南理工大学. 2010. 10-12.Yang M. Study on environmental geochemical effect of heavy metal elements(Zn,Ni,Cr)and fluorine in Dabaoshan Mining area[D]. Guangzhou:South China University of Technology.2010. 10-12.
[2]张超莹,郑西来,陈蕾,等.水库沉积物中铁、锰季节性释放的实验研究[J].水资源保护,2013,29(3):79-82,86.Zhang C Y,Zheng X L,Chen L,et al. Experimental study of seasonal release of manganese and iron from reservoir sediments[J]. Water Resources Protection,2013,29(3):79-82,86.
[3]陈静生.水环境化学[M].北京:高等教育出版社,1987.25-46.
[4] Kelepertzis E,Galanos E,Mitsis I. Origin,mineral speciation and geochemical baseline mapping of Ni and Cr in agricultural topsoils of Thiva Valley(central Greece)[J]. Journal of Geochemical Exploration,2013,125:56-68.
[5] Tian K, Huang B, Xing Z, et al. Geochemical baseline establishment and ecological risk evaluation of heavy metals in greenhouse soils from Dongtai,China[J]. Ecological Indicators,2017,72:510-520.
[6] Wang X Q. China geochemical baselines:sampling methodology[J]. Journal of Geochemical Exploration,2015,148:25-39.
[7] Jiang J B,Wang J,Liu S Q,et al. Background,baseline,normalization,and contamination of heavy metals in the Liao River Watershed sediments of China[J]. Journal of Asian Earth Sciences,2013,73:87-94.
[8]孔慧敏,左锐,滕彦国,等.基于地球化学基线的土壤重金属污染风险评价[J].地球与环境,2013,41(5):547-552.Kong H M,Zuo R,Teng Y G,et al. Pollution risk assessment of heavy metals in soil based on geochemical baseline[J]. Earth and Environment,2013,41(5):547-552.
[9]赵新儒,特拉津·那斯尔,程永毅,等.伊犁河流域土壤重金属环境地球化学基线研究及污染评价[J].环境科学,2014,35(6):2392-2400.Zhao X R, Telajin N, Cheng Y Y, et al. Environmental geochemical baseline of heavy metals in soils of the Ili River basin and pollution evaluation[J]. Environmental Science,2014,35(6):2392-2400.
[10] Karim Z, Qureshi B A, Mumtaz M. Geochemical baseline determination and pollution assessment of heavy metals in urban soils of Karachi,Pakistan[J]. Ecological Indicators,2015,48:358-364.
[11]郭威,殷淑华,徐建新,等.三峡库区(重庆—宜昌段)沉积物中钒的污染特征及生态风险评价[J].环境科学,2016,37(9):3333-3339.Guo W,Yin S H,Xu J X,et al. Pollution characteristics and ecological risk assessment of Vanadium in sediments of the Three Gorges Reservoir(Chongqing-Yichang section)[J].Environmental Science,2016,37(9):3333-3339.
[12]卓海华,孙志伟,谭凌智,等.三峡库区表层沉积物重金属含量时空变化特征及潜在生态风险变化趋势研究[J].环境科学,2016,37(12):4633-4643.Zhuo H H,Sun Z W,Tan L Z,et al. Temporal and spatial variation characteristics of the heavy metals content in the surface sediment and the potential ecological risk trends in the Three Gorges Reservoir area[J]. Environmental Science,2016,37(12):4633-4643.
[13] Gao B,Wei X,Zhou H D,et al. Pollution characteristics and possible sources of seldom monitored trace elements in surface sediments collected from Three Gorges Reservoir,China[J].Scientific World Journal,2014,2014:170639.
[14]郭威.三峡库区低水运行期表层沉积物重金属污染特征研究[D].郑州:华北水利水电大学,2016. 14-29.Guo W. Study on heavy metals pollution of sediments in the Three Gorges Reservoir during its operating period with low water level[D]. Zhengzhou:North China University of Water Resources and Electric Power,2016. 14-29.
[15]贾旭威,王晨,曾祥英,等.三峡沉积物中重金属污染累积及潜在生态风险评估[J].地球化学,2014,43(2):174-179.Jia X W, Wang C, Zeng X Y, et al. The occurrence,accumulation and preliminary risk assessment of heavy metals in sediments from the main tributaries in the Three Gorges Reservoir[J]. Geochimica,2014,43(2):174-179.
[16]王健康,高博,周怀东,等.三峡库区蓄水运用期表层沉积物重金属污染及其潜在生态风险评价[J].环境科学,2012,33(5):1693-1699.Wang J K,Gao B,Zhou H D,et al. Heavy metals pollution and its potential ecological risk of the sediments in Three Gorges Reservoir during its impounding period[J]. Environmental Science,2012,33(5):1693-1699.
[17]王健康,周怀东,陆瑾,等.三峡库区水环境中重金属污染研究进展[J].中国水利水电科学研究院学报,2014,12(1):49-53.Wang J K,Zhou H D,Lu J,et al. Reviews of heavy metals pollution in water environment of Three Gorges Reservoir[J].Journal of China Institute of Water Resources and Hydropower Research,2014,12(1):49-53.
[18] Han L F,Bo G,Zhou H D,et al. The spatial distribution,accumulation and potential source of seldom monitored trace elements in sediments of Three Gorges Reservoir,China[J].Scientific Reports,2015,5:16170.
[19]雷明,李昌晓,陈伟,等.三峡水库岸坡系统不同用地类型对土壤酶活性和土壤化学性质的影响[J].林业科学,2012,48(11):15-22.Lei M,Li C X,Chen W,et al. Effects of different land use patterns on soil enzymes activities and chemical properties on riverbank slopes of the Three Gorges Reservoir[J]. Scientia Silvae Sinicae,2012,48(11):15-22.
[20]刘久臣,刘晓端,徐清,等.上海崇明岛表层土壤重金属元素分布特征与环境地球化学基线值研究[J].岩矿测试,2010,29(3):245-249.Liu J C,Liu X D,Xu Q,et al. Distribution characteristics of heavy metals and their environmental geochemical baselines in top soils from Chongming Island of Shanghai City[J]. Rock and Mineral Analysis,2010,29(3):245-249.
[21]李艳.重庆紫色母岩及土壤重金属环境地球化学基线研究[D].重庆:西南大学,2017. 22-28.Li Y. Environmental geochemical baseline of heavy metal in purple mother rock and soil from Chongqing[D]. Chongqing:Southwest University,2017. 22-28.
[22]李艳,张薇薇,程永毅,等.重庆紫色母岩及土壤As、Hg环境地球化学基线研究[J].土壤学报,2017,54(4):917-926.LI Y, Zhang W W, Cheng Y Y, et al. Environmental geochemical baseline of As and Hg in purple soil and its parent rock in Chongqing[J]. Acta Pedologica Sinica,2017,54(4):917-926.
[23] Gao B,Zhou H D,Yu Y,et al. Occurrence,distribution,and risk assessment of the metals in sediments and fish from the largest reservoir in China[J]. RSC Advances,2015,5(74):60322-60329.
[24]黎彤,倪守斌.地球和地壳的化学元素丰度[M].北京:地质出版社,1990. 16-24.
[25]张立城,余中盛,章申.水环境化学元素研究[M].北京:中国环境科学出版社,1996. 20-25.
[26] Hakanson L. An ecological risk index for aquatic pollution control. a sedimentological approach[J]. Water Research,1980,14(8):975-1001.
[27] Wei X,Han L F,Gao B,et al. Distribution,bioavailability,and potential risk assessment of the metals in tributary sediments of Three Gorges Reservoir:the impact of water impoundment[J].Ecological Indicators,2016,61(Pt 2):667-675.
[28]中国环境监测总站.中国土壤元素背景值[M].北京:中国环境科学出版社,1990. 18-29.
[29]李湘凌,张颖慧,周涛发,等.合肥地区典型城镇土壤中As、Hg的环境地球化学基线[J].生态环境学报,2009,18(1):154-159.Li X L, Zhang Y H, Zhou T F, et al. Environmental geochemical baselines of soil metal elements in typical towns in Hefei area, Anhui province[J]. Ecology and Environment Sciences,2009,18(1):154-159.
[30] Zhang S,Yang D,Li F L,et al. Determination of regional soil geochemical baselines for trace metals with principal component regression:a case study in the Jianghan plain, China[J].Applied Geochemistry,2014,48:193-206.
[2]张超莹,郑西来,陈蕾,等.水库沉积物中铁、锰季节性释放的实验研究[J].水资源保护,2013,29(3):79-82,86.Zhang C Y,Zheng X L,Chen L,et al. Experimental study of seasonal release of manganese and iron from reservoir sediments[J]. Water Resources Protection,2013,29(3):79-82,86.
[3]陈静生.水环境化学[M].北京:高等教育出版社,1987.25-46.
[4] Kelepertzis E,Galanos E,Mitsis I. Origin,mineral speciation and geochemical baseline mapping of Ni and Cr in agricultural topsoils of Thiva Valley(central Greece)[J]. Journal of Geochemical Exploration,2013,125:56-68.
[5] Tian K, Huang B, Xing Z, et al. Geochemical baseline establishment and ecological risk evaluation of heavy metals in greenhouse soils from Dongtai,China[J]. Ecological Indicators,2017,72:510-520.
[6] Wang X Q. China geochemical baselines:sampling methodology[J]. Journal of Geochemical Exploration,2015,148:25-39.
[7] Jiang J B,Wang J,Liu S Q,et al. Background,baseline,normalization,and contamination of heavy metals in the Liao River Watershed sediments of China[J]. Journal of Asian Earth Sciences,2013,73:87-94.
[8]孔慧敏,左锐,滕彦国,等.基于地球化学基线的土壤重金属污染风险评价[J].地球与环境,2013,41(5):547-552.Kong H M,Zuo R,Teng Y G,et al. Pollution risk assessment of heavy metals in soil based on geochemical baseline[J]. Earth and Environment,2013,41(5):547-552.
[9]赵新儒,特拉津·那斯尔,程永毅,等.伊犁河流域土壤重金属环境地球化学基线研究及污染评价[J].环境科学,2014,35(6):2392-2400.Zhao X R, Telajin N, Cheng Y Y, et al. Environmental geochemical baseline of heavy metals in soils of the Ili River basin and pollution evaluation[J]. Environmental Science,2014,35(6):2392-2400.
[10] Karim Z, Qureshi B A, Mumtaz M. Geochemical baseline determination and pollution assessment of heavy metals in urban soils of Karachi,Pakistan[J]. Ecological Indicators,2015,48:358-364.
[11]郭威,殷淑华,徐建新,等.三峡库区(重庆—宜昌段)沉积物中钒的污染特征及生态风险评价[J].环境科学,2016,37(9):3333-3339.Guo W,Yin S H,Xu J X,et al. Pollution characteristics and ecological risk assessment of Vanadium in sediments of the Three Gorges Reservoir(Chongqing-Yichang section)[J].Environmental Science,2016,37(9):3333-3339.
[12]卓海华,孙志伟,谭凌智,等.三峡库区表层沉积物重金属含量时空变化特征及潜在生态风险变化趋势研究[J].环境科学,2016,37(12):4633-4643.Zhuo H H,Sun Z W,Tan L Z,et al. Temporal and spatial variation characteristics of the heavy metals content in the surface sediment and the potential ecological risk trends in the Three Gorges Reservoir area[J]. Environmental Science,2016,37(12):4633-4643.
[13] Gao B,Wei X,Zhou H D,et al. Pollution characteristics and possible sources of seldom monitored trace elements in surface sediments collected from Three Gorges Reservoir,China[J].Scientific World Journal,2014,2014:170639.
[14]郭威.三峡库区低水运行期表层沉积物重金属污染特征研究[D].郑州:华北水利水电大学,2016. 14-29.Guo W. Study on heavy metals pollution of sediments in the Three Gorges Reservoir during its operating period with low water level[D]. Zhengzhou:North China University of Water Resources and Electric Power,2016. 14-29.
[15]贾旭威,王晨,曾祥英,等.三峡沉积物中重金属污染累积及潜在生态风险评估[J].地球化学,2014,43(2):174-179.Jia X W, Wang C, Zeng X Y, et al. The occurrence,accumulation and preliminary risk assessment of heavy metals in sediments from the main tributaries in the Three Gorges Reservoir[J]. Geochimica,2014,43(2):174-179.
[16]王健康,高博,周怀东,等.三峡库区蓄水运用期表层沉积物重金属污染及其潜在生态风险评价[J].环境科学,2012,33(5):1693-1699.Wang J K,Gao B,Zhou H D,et al. Heavy metals pollution and its potential ecological risk of the sediments in Three Gorges Reservoir during its impounding period[J]. Environmental Science,2012,33(5):1693-1699.
[17]王健康,周怀东,陆瑾,等.三峡库区水环境中重金属污染研究进展[J].中国水利水电科学研究院学报,2014,12(1):49-53.Wang J K,Zhou H D,Lu J,et al. Reviews of heavy metals pollution in water environment of Three Gorges Reservoir[J].Journal of China Institute of Water Resources and Hydropower Research,2014,12(1):49-53.
[18] Han L F,Bo G,Zhou H D,et al. The spatial distribution,accumulation and potential source of seldom monitored trace elements in sediments of Three Gorges Reservoir,China[J].Scientific Reports,2015,5:16170.
[19]雷明,李昌晓,陈伟,等.三峡水库岸坡系统不同用地类型对土壤酶活性和土壤化学性质的影响[J].林业科学,2012,48(11):15-22.Lei M,Li C X,Chen W,et al. Effects of different land use patterns on soil enzymes activities and chemical properties on riverbank slopes of the Three Gorges Reservoir[J]. Scientia Silvae Sinicae,2012,48(11):15-22.
[20]刘久臣,刘晓端,徐清,等.上海崇明岛表层土壤重金属元素分布特征与环境地球化学基线值研究[J].岩矿测试,2010,29(3):245-249.Liu J C,Liu X D,Xu Q,et al. Distribution characteristics of heavy metals and their environmental geochemical baselines in top soils from Chongming Island of Shanghai City[J]. Rock and Mineral Analysis,2010,29(3):245-249.
[21]李艳.重庆紫色母岩及土壤重金属环境地球化学基线研究[D].重庆:西南大学,2017. 22-28.Li Y. Environmental geochemical baseline of heavy metal in purple mother rock and soil from Chongqing[D]. Chongqing:Southwest University,2017. 22-28.
[22]李艳,张薇薇,程永毅,等.重庆紫色母岩及土壤As、Hg环境地球化学基线研究[J].土壤学报,2017,54(4):917-926.LI Y, Zhang W W, Cheng Y Y, et al. Environmental geochemical baseline of As and Hg in purple soil and its parent rock in Chongqing[J]. Acta Pedologica Sinica,2017,54(4):917-926.
[23] Gao B,Zhou H D,Yu Y,et al. Occurrence,distribution,and risk assessment of the metals in sediments and fish from the largest reservoir in China[J]. RSC Advances,2015,5(74):60322-60329.
[24]黎彤,倪守斌.地球和地壳的化学元素丰度[M].北京:地质出版社,1990. 16-24.
[25]张立城,余中盛,章申.水环境化学元素研究[M].北京:中国环境科学出版社,1996. 20-25.
[26] Hakanson L. An ecological risk index for aquatic pollution control. a sedimentological approach[J]. Water Research,1980,14(8):975-1001.
[27] Wei X,Han L F,Gao B,et al. Distribution,bioavailability,and potential risk assessment of the metals in tributary sediments of Three Gorges Reservoir:the impact of water impoundment[J].Ecological Indicators,2016,61(Pt 2):667-675.
[28]中国环境监测总站.中国土壤元素背景值[M].北京:中国环境科学出版社,1990. 18-29.
[29]李湘凌,张颖慧,周涛发,等.合肥地区典型城镇土壤中As、Hg的环境地球化学基线[J].生态环境学报,2009,18(1):154-159.Li X L, Zhang Y H, Zhou T F, et al. Environmental geochemical baselines of soil metal elements in typical towns in Hefei area, Anhui province[J]. Ecology and Environment Sciences,2009,18(1):154-159.
[30] Zhang S,Yang D,Li F L,et al. Determination of regional soil geochemical baselines for trace metals with principal component regression:a case study in the Jianghan plain, China[J].Applied Geochemistry,2014,48:193-206.