【摘要】 铬是人体和动物必需的微量元素之一。但高浓度的铬,尤其是地下水中的Cr(Ⅵ)可能对人体健康和环境造成很大的危害,因此研究高浓度Cr(Ⅵ)污染地下水的修复技术至关重要。应用铸铁和椰壳活性炭作为模拟柱中渗透反应格栅(PRB)的反应介质,为了防止实验过程发生堵塞,添加适当河沙,通过铸铁的还原作用及椰壳活性炭的吸附作用研究PRB对高浓度Cr(Ⅵ)污染地下水的修复效能。结果表明:铸铁、椰壳活性炭、河沙的质量比为3∶1∶4、Cr(Ⅵ)为400 mg/L条件下,完全穿透时反应材料对Cr(Ⅵ)整体去除率为67.0%,PRB反应介质寿命为165d;侧孔Cr(Ⅵ)浓度随时间延长而逐渐增大,离进水口越近,材料去除Cr(Ⅵ)的能力降低越快;出水及沿程在没有Cr(Ⅵ)检出时pH为4.5～7.0,出水有Cr(Ⅵ)检出时pH均大于7.0;出水中无Cr(Ⅵ)检出时,总铁(TFe)含量较高,Fe(Ⅲ)含量较少,有大量Fe(Ⅱ)产生,出水有Cr(Ⅵ)检出时,对应的Fe(Ⅲ)和TFe检出浓度均较低,说明柱体内铸铁材料基本钝化完全。更多还原

【Abstract】 Chromium is one of the essential trace elements for human and animal.But the high concentration of chromium especially the Cr(Ⅵ)in groundwater may cause great harm for human health and environment.Therefore,it is very important to study the remediation technology of groundwater contaminated by high concentration Cr(Ⅵ).In this paper,cast iron and coconut shell activated carbon were used as simulated column permeable reactive barrier(PRB)reaction medium.In order to prevent the potential clogging problem during the experiment,appropriate river sand was packed in the column to study the PRB remediation efficiency of high concentration Cr(Ⅵ)contaminated groundwater by reduction of cast iron and adsorption of coconut shell activated carbon.The results showed that mass concentration 400 mg/L Cr(Ⅵ)was remediated by cast iron,coconut shell activated carbon and river sand mass ratio of 3∶1∶4,the overall removal rate of Cr(Ⅵ)by reactive materials was 67.0% when column was fully penetrated,and the life of PRB reaction medium was 165 days.The Cr(Ⅵ)concentration in the side ports gradually increased with time,and the closer to the inlet,the faster the ability of material to remove Cr(Ⅵ)decreased.The pH of the effluent and along the way was 4.5-7.0 when no Cr(Ⅵ)was detected,and the pH was greater than 7.0 when the Cr(Ⅵ)was detected.When there was no Cr(Ⅵ)detected in the effluent,the content of total iron(TFe)was higher,Fe(Ⅲ)was less,and Fe(Ⅱ)was abundant.When Cr(Ⅵ)was detected in the effluent,the TFe and Fe(Ⅲ)content was less,which indicated that the cast iron material in the column was passivated completely.更多还原