EFFECT OF REDOX CONDITION AND MICROBIAL ACTION ON HEAVY METALS TRANSFORMATION IN RESERVOIR SEDIMENTS
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摘要: 为探明沉积物-水界面间重金属的迁移转化机制,以西北某水库的表层沉积物为研究对象,通过控制溶解氧含量,设计了对该水库沉积物抑菌、加碳源的室内培养实验。结果表明:好氧培养28 d后,上覆水体中6种重金属浓度降低了46.3%~100%,沉积物中重金属总量均增加,其中活性态含量下降,残渣态含量上升,尤其是Cd和Pb的残渣态含量占总量比值(R/T)分别增加了33.32%和16.11%;厌氧条件下浓度变化的趋势则相反,上覆水体中Pb的浓度比初始浓度增加2.36倍。微生物作用下(加碳源),上覆水体中6种重金属浓度均低于高温灭菌处理,而沉积物中重金属总量相对增加,同时,加碳源后6种重金属的(R/T)值高于灭菌处理。说明微生物活动可使上覆水体中重金属迁移至沉积物中,且将活性态转化为风险低的残渣态,从而降低重金属对人体的危害。因此,提高水库溶解氧含量和微生物数量,对于降低沉积物中重金属活性,富集、固定重金属具有重要作用。Abstract: In order to explore the migration and transformation mechanism of heavy metals between sediment and water interface, we took the surface sediment of a reservoir in Northwest China as the research object. By controlling redox conditions, an indoor simulation experiment was designed including heat sterilization and adding carbon sources to the sediments. It was found that after 28 days of aerobic cultivation, the concentration of six heavy metals in the overlying water decreased by 46.3%~100%, and the total content of heavy metals in the sediment all increased; the content of active form of the six heavy metals decreased, and the content of residual form increased, especially the ratio of residual form content to total amount of Cd and Pb (R/T) increased by 33.32% and 16.11% respectively, compared with the original sample; under anaerobic condition, the trend of concentration change was opposite, and the concentration of Pb in the overlying water was 2.36 times higher than the initial one. Under the action of microorganisms, the concentration of six heavy metals in the overlying water was lower than that of the high-temperature sterilization treatment, while the total amount of heavy metals in the sediment was increased. At the same time, the R/T values of six heavy metals, after adding carbon source, were higher than those of sterilization treatment. This indicated that microbial activity can immobilize heavy metals, causing them to migrate from overlying water to sediments, and converting active states into low-risk residual states, thereby reducing the toxicity of heavy metals to human health. Therefore, increasing the dissolved oxygen content and microbial population in reservoirs played an important role in reducing the activity of heavy metals in sediments, enriching and fixing heavy metals.
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Key words:
- heavy metals /
- redox condition /
- sterilization /
- sediments /
- the overlying water
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[1] ZHAO W T, GU C H, YING H, et al. Fraction distribution of heavy metals and its relationship with iron in polluted farmland soils around distinct mining areas[J].Applied Geochemistry,2021,130:104969. [2] LIANG G N, ZHANG B, LIN M, et al. Evaluation of heavy metal mobilization in creek sediment:influence of RAC values and ambient environmental factors[J].Science of the Total Environment,2017,607/608:1339-1347. [3] 华东理工大学分析化学教研组,四川大学工科化学基础课程教学基地.分析化学[M].6版. 北京:高等教育出版社,2009,440. [4] 王禄仕,张亚宁,朱维晃.汤峪水源水库沉积物中重金属形态分布特征及其潜在生态风险评价[J].西安建筑科技大学学报(自然科学版),2010,42(4):567-572. [5] WANG Z, LUO Y F, ZHENG C L, et al.Spatial distribution, source identification, and risk assessment of heavy metals in the soils from a mining region:a case study of Bayan Obo in northwestern China[J].Human and Ecological Risk Assessment, 2020,27(5/6):1276-1295. [6] XIONG B, LI R P, JOHNSON D, et al.Spatial distribution, risk assessment, and source identification of heavy metals in water from the Xiangxi River, Three Gorges Reservoir Region, China[J].Environmental Geochemistry and Health,2020,43(2):915-930. [7] 吴蕾,刘桂建,周春财,等.巢湖水体可溶态重金属时空分布及污染评价[J].环境科学,2018,39(2):738-747. [8] 张密,文波,黄凌霞,等.氧化还原条件对城市水体沉积物重金属迁移转化的影响[J].华东师范大学学报(自然科学版),2016(2):160-170. [9] 陈春乐,田甜,郭孝玉,等.淋洗修复后残留土壤中重金属的再释放及环境风险[J].环境科学学报,2020,40(9):3405-3414. [10] 刘洁,孙可,韩兰芳.生物炭对土壤重金属形态及生物有效性影响的研究进展[J].环境化学,2021,40(6):1643-1658. [11] RAURET G, LO'PEZ-SA'NCHEZ J. F, SAHUQUILLO A, et al.Improvement of the BCR three step sequential extraction procedure prior to the certifification of new sediment and soil reference materials[J].J Environ Monit,1999,1:57-61. [12] 常春英,曹浩轩,陶亮,等.固化/稳定化修复后土壤重金属稳定性及再活化研究进展[J].土壤,2021,53(4):682-691. [13] 钟松雄,尹光彩,陈志良,等.Eh、pH和铁对水稻土砷释放的影响机制[J].环境科学,2017,38(6):2530-2537. [14] KELDERMAN P, OSMAN A A. Effect of redox potential on heavy metal binding forms in polluted canal sediments in Delft (The Netherlands)[J].Water Research,2007,41(18):4251-4261. [15] 杨宾,罗会龙,刘士清,等.淹水对土壤重金属浸出行为的影响及机制[J].环境工程学报,2019,13(4):936-943. [16] 陶玲,刘伟,刘瑞珍,等.酸活化坡缕石对土壤中Cd的钝化效果研究[J].岩石矿物学杂志,2021,40(4):795-803. [17] 朱成斌,胡菁,龙云川,等.贵州草海沉积物重金属元素分布特征及健康风险评价[J].环境科学学报,2021,41(6):2212-2221. [18] 王书航,王雯雯,姜霞,等. 蠡湖沉积物重金属形态及稳定性研究[J].环境科学,2013,34(9):3562-3571. [19] KUBICKI J D, TUNEGA D, KRAEMER S. A density functional theory investigation of oxalate and Fe(Ⅱ) adsorption onto the (010) goethite surface with implications for ligand- and reduction-promoted dissolution[J].Chemical Geology,2017, 464:14-22. [20] LUEDER U, BO B J,KAPPLER A, et al. Photochemistry of iron in aquatic environments[J].Environmental Science:Processes and Impacts,2020,22(1):12-24. [21] 胡世文,刘同旭,李芳柏,等.土壤铁矿物的生物-非生物转化过程及其界面重金属反应机制的研究进展[J]. 土壤学报,2022,59(1):54-65. [22] AEPPLI M, VRANIC S,KAEGI R, et al. Decreases in iron oxide reducibility during microbial reductive dissolution and transformation of ferrihydrite[J].Environmental Science and Technology,2019,53(15):8736-8746. [23] 李冉.生物炭与菌剂对猪粪堆肥中重金属形态转化的影响研究[D].保定:河北农业大学,2018. [24] 段磊,孙亚乔,童秀娟,等.动水条件下沉积物-水界面微生物与铬的相互作用机理[J].生态环境学报,2020,29(7):1412-1418. [25] GAO Y J,JIA J L,XI B D,et al.Divergent response of heavy metal bioavailability in soil rhizosphere to agricultural land use change from paddy fields to various drylands[J].Environmental Science:Processes and Impacts,2021,23(3):417-428. [26] RAJBONGSHI A, GOGOI S B.A review on anaerobic microorganisms isolated from oil reservoirs[J].World Journal of Microbiology and Biotechnology,2021,37(7):111.
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