裂隙岩体含水层六价铬污染的修复

Remediation of fractured rock aquifers contaminated by hexavalent chromium

结合山东省某机械公司岩体污染场地六价铬污染修复工程,详细分析研究了基岩裂隙水中污染物的运移特征、修复技术选择与施工、修复效果评价。研究表明:基岩裂隙水中六价铬污染羽的形态与规模主要取决于地下水流场、含水层富水性及断裂带产状,污染羽的深度取决于含水层埋深;基岩裂隙水复杂的水力联系条件是引起污染空间分布差异性大的控制因素。通过论证分析,提出了原位阻隔、地下水化学还原与抽水异位处理的多技术联合修复方案,修复后所有监测井内地下水中六价铬浓度均低于地下水质量Ⅳ类标准0.1mg/L,修复率达到99%以上。该工程的成功实施可为基岩裂隙含水层污染修复工程的设计与施工提供参考。

The contamination characteristics of bedrock fissured aquifer, selection and implementation of remediation technologies, and evaluation of remediation effects are analyzed based on the remediation project of hexavalent chromium-contaminated groundwater in a machinery company in Shandong Province. The results show that the shape and the scale of hexavalent chromium-contaminated plume in bedrock fissured aquifer mainly depends on groundwater flow field, water abundance of aquifer and occurrence of fault zone. The buried depth of contamination plume depends on that of aquifer. The complex hydraulic connection condition of bedrock fissured water is an important factor causing great difference in spatial distribution of contamination concentration in the site. Through technical and economical analysis, a multi-technology combined remediation scheme including groundwater barrier, ex-situ treatment after pumping and in-situ chemical reduction technology is put forward. After field remediation, the concentration of hexavalent chromium in groundwater in all monitoring wells is lower than that of class IV standard(0.1 mg/L) in "Chinese Standard for Groundwater Quality", and the successful remediation percentage is almost 99%. This successful implementation project can provide reference for the design and construction of remediation of contaminated fissured rock aquifers.