高锑区水-沉积物体系中锑形态迁移、转化及毒性评价研究

Antimony was listed as a priority pollutant by US Environmental Protection Agency and the European Union. Its toxicity to aquatic animals and plants is critically determined by its species. Research on antimony focuses on its toxicity and potential carcinogenicity to humans, but rarely on the separation, migration, transformation, and quantitative analysis of its species. This project was based on the water-sediments in a high-antimony area, and on field sampling (cylindrical sediment and interstitial water) and indoor simulation experiment. The space-time distributions of different antimony spciation in water- sediments, and the influencing factors, were investigated. The mechanisms of shape transformations between water and sediments were analyzed. Moreover, with field-sampled aquatic organisms and indoor plant experiments, the mechanisms of antimony form transformations, and the migration and transfor- ation rules of antimony in plants, were analyzed by the new analytical techniques, which ensured high precision. The accumulation and toxic effects of antimony in aquatic plants were evaluated to reveal the migration/transformation mechanisms and the effects of antimony species in water-sediments, as well as the mechanisms of migration and transformation of antimony in aquatic plants. These results will provide reference for treatment of antimony pollution.

锑被美国环境保护署和欧盟列为优先控制污染物，它的形态变化对水生动植物毒性大小有重要的决定性。锑的毒性和对人类潜在致癌性，是关注的热点，而目前关于锑不同形态的分离、迁移、转化和定量分析仍然研究不足。本项目以高锑区水-沉积物为研究对象，通过沉积物柱状采样和间隙水等系统样品的采集，结合实验室模拟实验，研究锑在水-沉积物中不同形态的时空分布特征，分析其影响因素；分析水与沉积物中锑形态转化的机制。采用水生生物的野外采集和室内植物实验，高精度分析锑不同形态转化过程中的影响机理及其在植物中的迁移、转化规律；评价锑在水生植物中的积累与毒性作用，以揭示不同形态锑在水-沉积物体系中的迁移转化机理及影响因素，及其在水生生物中的迁移、转化机制，为锑污染治理提供参考。

锑被美国环境保护署和欧盟列为优先控制污染物，锑的毒性和对人类潜在致癌性，是目前关注的热点，本项目研究了高锑区水-沉积物体系中锑的分布、迁移、富集机制。主要内容如下：. 1.采集了淮北3个采煤塌陷湖上覆水体和沉积物样品，3个塌陷湖已经受到一定的锑污染，根据分配系数，LSH湖泊存在较大的生态危害。表层沉积物中锑在塌陷湖中的空间分布不均匀，变异系数处于中等变异；根据地积累指数法，塌陷湖沉积物锑具有轻度-中度生态风险；Sb在3个塌陷湖中存在人为输入过程，来源复杂，可能主要来自于矸石堆的淋溶、工业废水排放等点源污染。. 2.锑对玉米的生理和光合作用的影响，随着土壤中锑含量的增加，转运系数也逐渐增加，这可能有利于保护其光合机构，从而增强对锑的耐受能力。随着土壤中锑含量的增加，玉米的光合参数(Pn, gs, E)、PSII最大光化学效率(Fv/Fm)、叶绿素含量以及生物量明显下降，而MDA含量和iWUE则明显上升，表明高浓度的锑胁迫会严重影响玉米的生长发育，进而影响到玉米的产量和品质。上述这些指标可以作为检验锑毒害的探针，从而可以确定玉米适合修复污染地的重金属锑浓度范围。本研究为经济作物玉米应用于重金属污染土壤修复提供一定的参考和依据。. 3.采用蚯蚓处理污泥，不同处理Eisenia fetida体内重金属含量差异较大，对Eisenia fetida的生长和繁殖影响较小，Eisenia fetida对镉的富集作用大，而对锑的富集作用小。. 4.利用改性活性炭去除水体中的锑，改性活性炭吸附锑的最佳温度为300K，升高温度不利于吸附锑，降低温度有利于吸附锑；在锑初始浓度 0.5～4.5mg/L范围内,改性活性炭吸附量随着锑初始浓度的增加而增加，基本成线性关系；改性活性炭吸附锑的最佳 pH=4，300K时，改性活性炭吸附锑的吸附等温线与Langmuir吸附等温式非常吻合，具有良好的吸附性能，能够有效去除不同水体中锑离子。