汞污染地块风险全生命周期管控技术体系研究

风险全周期管理是推进汞污染地块风险管控,有效实现地块安全可控的重要方式.在《关于汞的水俣公约》全球履约背景下,为有效提升汞污染地块的风险预防与管控能力,该文对汞污染地块风险管控技术体系进行了深入研究.在深入分析污染地块健康风险全生命周期特征的基础上,围绕地块风险源头-暴露途径-环境受体3个核心风险要素,并结合国内外技术研发与工程示范经验,构建出适用于此类污染地块的风险全周期分类管控技术体系.该体系根据土壤与地下水风险管控标准评价地块污染水平,并结合地块敏感目标和暴露途径等暴露情景对地块进行分类管控决策.通过对工程修复、风险管控、制度控制等进行多技术有机耦合,可实现对汞污染地块全方位、多角度、系统化的风险管理,即在风险产生、风险发展与风险消褪的各个环节,分别施以源头预防、过程控制及长期管理措施,有效遏制地块新增风险的基础上,实现污染地块风险的安全可控.该技术体系存在如下特征:1)基于风险的管理决策可以反映地块管理的科学内涵;2)分类风险管控策略可以有效节约成本,实现最大的管控净效益;3)以全生命周期管理为基本理念,实现“源头-过程-末端”的全流程风险控制.

Study on the technical system of life cycle risk management for mercury-contaminated site s

With the continuous development of global society and economy, environmental mercury (Hg) pollution had increasingly attracted more and more attention due to severely negative impact on both public health and the ecological safety. Life-cycle risk management acted as an important approach to effectively promote the risk management effect of mercury-contaminated sites. In order to effectively improve the capacity of risk prevention and control of mercury contaminated sites, the comprehensive technical system for risk management of Hg contamination was established under the background of the Minamata Convention on Mercury, a global treaty on ecosystem and human health protection. The characteristics of health risk presented in contaminated sites were studied and a life-cycle management system was designed based on the existing technologies and application experiences at home and abroad. Relying on this system, the life-cycle risk management was accomplished through the application of enhancing engineering remediation, risk control, institutional control, etc., which aimed to decrease the negative health effects and ecological damages associated with Hg exposure. The site risks levels were divided into 3stages based on exposure scenarios from site survey and contamination levels evaluated according to risk screening standards. The measures of risk prevention, process control and long-term management were implemented in the stages of risk generation, risk development and risk elimination, respectively. The main features of this system are summarized as follows: 1) The risk-based management decision reflects the scientific connotation of the contaminated site management; 2) Cost is saved through classified risk management, towards to the maximum net benefit from site management; 3) The whole process risk control is realized with the concept of life cycle management.