棕地地下水污染修复技术筛选方法研究——以某废弃化工厂污染场地为例

Screening process of brownfield site groundwater remedial technologies:a case study of an abandoned chemical factory contaminated site

科学合理的地下水污染修复技术筛选方法对于有效修复受污染地下水体、节约修复工程成本、保护地下水资源、维护生态系统安全和人体健康具有重要意义。以某化工厂遗址早期排污渗坑为目标污染源,在结合水文地质勘查和地下水人体健康风险评价的基础上确定场地受污染地下水修复目标污染物,根据污染物迁移性、降解性、人体健康风险等指标及抽出处理、化学修复、生物修复、渗透反应格栅等地下水污染修复技术特点,使用偏好顺序结构评估法(PROMETHEE)进行修复技术筛选。结果显示,该场地地下水中主要污染物为1,2-二氯乙烷、1,4-二氯苯等有机污染物,其中1,2-二氯乙烷在呼吸吸入条件下的最大致癌风险达9.54×10-7。化学清除、监测自然衰减等四项技术适用于该场地地下水1,2-二氯乙烷修复,化学清除法综合排序分值最高,而在成本优先控制条件下,监测自然衰减技术更为适宜。研究对于我国场地地下水污染调查评估及修复工作具有积极的参考意义。

Scientific and reasonable screening method of groundwater pollution remediation technologies is of great importance to efficient remediate the polluted groundwater, saving remediation program cost and groundwater resource and ecology and human health protection. Considered as a target pollution source,hydrological survey combined with groundwater pollution human health risk were conducted in a discarded chemical factory site with a drain contamination pool,and PROMETHEE method was used to screen efficient technologies for local groundwater pollution remediation based on pollutants characteristics such as migration,degradation and human health risk,and technologies applicability analysis among pump treat,chemical reduction,bioremediation and permeable reactive barriers,etc. Study results suggested that local groundwater was polluted by organic pollutants such as 1,2- DCA and 1,4- DCB,the largest cancerigenic risk of 1,2-DCA through inhaled ingestion was about 9. 54 × 10^- 7. Chemical reduction,monitored natural attenuation,bioremediation and air sparging were considered to be suitable technologies for remediation of local groundwater 1,2- DCA pollution. The total ranking score of chemical reduction was the highest while monitored natural attenuation had a highest ranking score considering cost control. This study had a positive reference meaning for field investigation and assessment and remediation of groundwater pollution in China.