河湖沉积物中重金属镉污染治理技术及应用

Technology Research and Application in Heavy Metal Cd Pollution Control in Rivers and Lakes Sediments

随着现代工农业的迅猛发展,矿山开采、冶炼及农业生产等活动逐渐增加,向环境排放的重金属Cd含量也逐年增多。湖泊沉积物作为“储蓄库”,其Cd污染问题也日益严重。河湖底泥中富集的Cd在水环境条件发生改变时,易重新释放入水体,被水生生物体吸收利用,并通过食物链对人体健康产生危害。目前,我国河流湖泊底泥中呈现出不同程度的Cd污染,且在部分底泥中Cd已成为污染最严重的重金属,对重金属Cd污染底泥的处理与处置已刻不容缓。因此,文中综述了我国湖泊沉积物中重金属Cd污染现状及潜在生态风险,依次介绍了Cd污染底泥原位修复治理技术研发进展及不同修复方法的机理与应用,并对湖泊重金属Cd污染底泥治理技术前景进行了展望,拟为湖泊重金属Cd污染底泥修复提供技术参考:(1)研究如何系统地统计分析Cd污染底泥现状及潜在生态风险,规定不同底泥环境中Cd的规范值十分必要;(2)碳基吸附剂的再生及可分离性等问题有待解决;(3)开展植物修复Cd污染底泥的中试试验及规模应用有利于底泥修复技术的研究;(4)选择合适有效的微生物和水生植物相结合对沉积物Cd进行控制和修复,可能是未来治理湖泊底泥Cd污染的重要研究方向。

With the rapid development of modern industry and agriculture,activities such as mining,smelting and agricultural production have gradually increased,and the heavy metal cadmium(Cd)discharged into the environment has also increased.As a"deposit bank",the problem of cadmium pollution in lake sediments has become increasingly serious.Cd enriched in the sediment of rivers and lakes is easy to be re-released into water body as the environment conditions changed,and can be absorbed and utilized by aquatic organisms,causing harm to human health through the food chain.At present,rivers and lakes present different degrees of Cd pollution in the sediment,and Cd has become one of the most serious heavy metal in sediment,so it is urgent to treat and dispose the sediment with Cd pollution.Therefore,this study summarizes the status of Cd pollution and potential ecological risks in rivers and lakes sediments,so as to describes the development,mechanism and application of in-situ remediation technology for Cd polluted sediment.The technology prospects of Cd polluted sediment is predicted,intending to provide technical reference for the remediation of Cd polluted sediment:(1)It is necessary to study how to systematically analyze the status quo and potential ecological risks of Cd polluted sediment,and to specify the standard value of Cd in different environments;(2)The regeneration and separability of carbon-based adsorbents need to be solved;(3)Pilot experiments and large-scale application are conducive to the study of phytoremediation technology for Cd polluted sediment;(4)The combination of microorganisms and aquatic plants may be an important research direction for remedying Cd polluted sediment in the future.