Zhang Rui-hua, Sun Hong-wen
College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
Huan Jing Ke Xue. 2007 May;28(5):1131-6.
Remediation efficiency on artificial chromate [Cr (VI)] contaminated soil and a field Cr (VI) contaminated soil around industrial Cr residue (Tianjin Tongsheng Chemical and Industrial Factory) by using electrokinetic method was studied. Moreover, the electrokinetic method was combined with iron permeable reactive barrier (PRB) and a better combination mode was found. The remediation efficiency of the combined method was compared with electrokinetic method. The results showed that Cr (VI) contaminated soil can be remedied effectively by electrokinetic method. For artificial contaminated soil, the removal ratio of Cr (VI) reached 98%-100%, while the total Cr was removed about 80% near the anode, and more than 90% near the cathode, where the content of Cr came back to soil background. The reduction of Cr (VI) to Cr (III) occurred during the soil remediation, and more than 90% of the residual Cr was Cr (III) at the end of remediation. More than 98% Cr (VI) were removed, whereas only 75%-77% of total Cr were removed from the heavily contaminated field soil as the soil contained 28% Cr (III) initially. Soil pH increased near the cathode and decreased near the anode, while the change of soil pH was insignificant in the middle. In situ combination mode of electrokinetic and PRB is a better method that could take the full advantages of the two technologies. The removal efficiency of total Cr was about 90% at the end of the remediation, which is better than electrokinetic method especially near the anode, and had less effect on soil pH.
研究了采用电动修复法对人工铬酸盐[Cr(VI)]污染土壤以及工业铬渣（天津同盛化工厂）周边某场地铬(VI)污染土壤的修复效果。此外，将电动修复法与铁渗透反应屏障（PRB）相结合，找到了一种更好的组合方式，并将该组合方法的修复效果与电动修复法进行了比较。结果表明，电动修复法能有效修复铬(VI)污染土壤。对于人工污染土壤，铬(VI)的去除率达到98% - 100%，阳极附近总铬的去除率约为80%，阴极附近超过90%，阴极处铬含量恢复到土壤背景值。在土壤修复过程中发生了铬(VI)向铬(III)的还原，修复结束时残留铬中超过90%为铬(III)。对于重度污染的场地土壤，虽然最初土壤中含28%的铬(III)，但仍有超过98%的铬(VI)被去除，而总铬的去除率仅为75% - 77%。阴极附近土壤pH升高，阳极附近土壤pH降低，中间区域土壤pH变化不明显。电动修复与PRB的原位组合方式是一种能充分发挥两种技术优势的更好方法。修复结束时总铬的去除效率约为90%，优于电动修复法，尤其是在阳极附近，且对土壤pH的影响较小。
