粉煤灰中微量重金属元素的溶出研究
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摘要
以不同来源的粉煤灰为研究对象,采用水平振荡试验,研究不同溶出试验条件对粉煤灰中微量重金属元素溶出量的影响规律,并结合SEM与XRD分析其溶出机理.结果表明:振荡时间、浸提液pH值、液固比、颗粒细度对重金属元素的溶出都有一定的影响.不同来源的粉煤灰在相同时间内Cr和Zn溶出量较大,其次是Cu.Cu,Cr,Zn均呈两性溶出趋势,即在pH=7～10内溶出量最低而强酸碱条件下容易溶出.溶出后粉煤灰的主要物相种类未发生变化,重金属元素的溶出是部分矿物发生溶解、结构解体所致.
The effects of various leaching conditions on the leachability of heavy metals in fly ash were investigated by horizontal oscillatory test with different sources of fly ash. The leaching mechanism was analyzed by SEM and XRD. The test results show that the oscillation time, the pH value of the extract, the ratio of liquid to solid and the fineness of fly ash had a certain influence on the leachability of heavy metals in fly ash. The leachability of Cr and Zn was the larger in the same time, and followed by Cu. Cu, Cr and Zn showing amphoteric leaching trends,which areat the lowest leachabilityin pH =7 ～10 and easy to leach under strong acid and alkali conditions. There was no significant change in the kinds of major minerals after leaching. The leaching of heavy metal elements was caused by the dissolution of some minerals and the disintegration of their structure.
The effects of various leaching conditions on the leachability of heavy metals in fly ash were investigated by horizontal oscillatory test with different sources of fly ash. The leaching mechanism was analyzed by SEM and XRD. The test results show that the oscillation time, the pH value of the extract, the ratio of liquid to solid and the fineness of fly ash had a certain influence on the leachability of heavy metals in fly ash. The leachability of Cr and Zn was the larger in the same time, and followed by Cu. Cu, Cr and Zn showing amphoteric leaching trends,which areat the lowest leachabilityin pH =7 ～10 and easy to leach under strong acid and alkali conditions. There was no significant change in the kinds of major minerals after leaching. The leaching of heavy metal elements was caused by the dissolution of some minerals and the disintegration of their structure.
引文
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[13]Remond S,Rbent Z D,Pimienta R.Effects of the Incorporation of Municipal Solid Waste Incineration Fly Ash in Cement Pastes and Mortar II:Modeling[J].Cement and Concrete Research,2002(4):565-576.
[14]王茂国,王发洲,商得辰,等.CdO对硅酸三钙形成的影响及其固溶效应[J].材料科学与工程学报,2016(2):208-212.
[15]袁晓露,周世华.水泥制品中重金属元素的溶出特性与环境安全评估[J].混凝土与水泥制品,2016(7):38-42.
[2]高瑞,程芳琴.冶金工业固体废物粉煤灰的综合利用[J].再生资源与循环经济,2010(11):38-41.
[3]赵文霞,冯辉.粉煤灰中重金属元素分布规律的研究[J].粉煤灰综合利用,2002(2):38-39.
[4]武艳菊,刘振学,初乃波.粉煤灰中重金属元素镉的分析测定[J].粉煤灰综合利用,2005(1):47-48.
[5]郭朝晖,程义,柴立元,等.有色冶炼废渣的矿物学特征与环境活性[J].中南大学学报(自然科学版),2007(6):1100-1105.
[6]陆莹,王志伟.固体废弃物的酸碱度与浸提剂pH值的相关性研究[J].光谱学与光谱分析,2002(1):168-170.
[7]Shim Y S,Rhee S W,Lee W K.Comparison of leaching characteristics of heavy metals from bottom and fly ashes in Korea and Japan[J].Waste Management,2005(25):473-480.
[8]Izquierdo M,Querol X.Leaching behavior of elements from coal combustion fly ash:an overview[J].International Journal of Coal Geology,2012(94):54-66.
[9]Komonweeraket K K,Bora C,Ahmet H A,et al.Effects of pH on the leaching mechanisms of elements from fly ash mixed soils[J].Fuel,2015(140):788-802.
[10]Sandeep P,Sahu S K,Kothai P,et al.Leaching Behavior of Selected Trace and Toxic Metals in Coal Fly Ash Samples Collected from Two Thermal Power Plants,India[J].Bulletin of Environmental Contamination and Toxicology,2016(3):425-431.
[11]Gallardo S,D van Hullebusch E, Pangayao D,et al.Chemical,Leaching,and Toxicity Characteristics of Coal Ashes from Circulating Fluidized Bed of a Philippine Coal-Fired Power Plant[J].Water,Air,&Soil Pollution,2015(9):312-322.
[12]Jin Z S,Liu T Z,Yang Y G,et al.Leaching of cadmium,chromium,copper,lead,and zinc from two slag dumps with different environmental exposure periods under dynamic acidic condition[J].Ecotoxicology and Environmental Safety,2014(104):43-50.
[13]Remond S,Rbent Z D,Pimienta R.Effects of the Incorporation of Municipal Solid Waste Incineration Fly Ash in Cement Pastes and Mortar II:Modeling[J].Cement and Concrete Research,2002(4):565-576.
[14]王茂国,王发洲,商得辰,等.CdO对硅酸三钙形成的影响及其固溶效应[J].材料科学与工程学报,2016(2):208-212.
[15]袁晓露,周世华.水泥制品中重金属元素的溶出特性与环境安全评估[J].混凝土与水泥制品,2016(7):38-42.