污染场地修复药剂安全利用问题及对策

我国污染场地修复过程中常采用固化/稳定化、淋洗或化学氧化/还原等修复技术，通过改变污染物赋存形态、降低污染物浓度或消除污染物的方式控制环境风险.在这些技术应用过程中，修复药剂对土壤和地下水环境的潜在风险已经引起关注.目前我国《土壤污染防治法》明确提出:相关部门应筛选评估并公布土壤中重点控制的有毒有害物质名录、禁止在土壤中使用重金属超标的降阻产品、修复活动不得造成新的危害、加强肥料等产品的登记并组织开展安全性评价、修复方案中应包括地下水污染防治等内容.但目前还没有制定针对修复药剂安全性的相应标准或技术规范.修复药剂可能会造成土壤理化性质、土壤微生物活性及数量的改变，破坏土壤生态系统或二次污染土壤，还会迁移进入地下水，造成水质恶化并引发风险；本文阐述了污染场地修复中常用修复药剂的修复机理及存在的问题，梳理了现有修复药剂评价和管控方法，提出了基于土壤性质、微生物和地下水安全的修复药剂安全评价及管控建议，为场地修复中修复药剂安全利用及风险管控提供参考. 

Problems and Strategies of Safe Utilization of Agents for Contaminated Sites

Technologies such as solidification/stabilization, leaching or chemical oxidation/reduction are used to control, mitigate or eliminate pollutants in the remediation of contaminated sites in China. These processes include the transformation of pollutant compounds, reduction of their concentration or even their elimination, so the environmental risks of pollutants can be controlled. However, the potential safety risks of these remediation agents to the soil and groundwater environment have caused widespread concern. Moreover, there are no specific standards or technical specifications regarding the safety of the remediation agents. The Soil Pollution Prevention and Control Law clearly states that the related environmental departments should screen and evaluate the main toxic and hazardous substances to be controlled in soil, prohibit the use of products with excessive heavy metal content in the soils to avoid the creation of new hazards during the remediation activities, strengthen the registration of fertilizers and other products, and organize safety evaluations. In addition, the remediation plan should include the prevention and control of groundwater pollution. In fact, some remediation agents and products can not only cause changes in the physical and chemical properties and microbial activity, but also damage the ecosystem and cause secondary pollution of the soil. Moreover, these remediation agents and products can migrate to groundwater. This migration can lead to the risk of deterioration of water quality and groundwater pollution. The study explained the remediation mechanism and current problems of the commonly used remediation agents in the remediation of contaminated sites, assessed the control methods of existing remediation agents, and propose risk assessment and management and control recommendations for remediation agents based on soil properties, microorganisms and groundwater safety. Therefore, this study can provide a reference for the safety evaluation and control of the risks of the remediation agents.