Chang Jih-Hsing, Liao Ying-Chih
Department of Environmental Engineering and Management, Chaoyang University of Technology, 168 GiFeng East Road, WuFong Hsiang, 413 Taichung County, Taiwan.
J Hazard Mater. 2006 Feb 28;129(1-3):186-93. doi: 10.1016/j.jhazmat.2005.08.030. Epub 2005 Sep 26.
Electrokinetics (EK) is a technique for soil remediation. However, the acid produced due to the water electrolysis at the anode will cause soil acidification, which may destroy the soil constituents, and reduce contaminant removal efficiency. The formation of a base front produced at the cathode will result in the precipitation of metal hydroxides and a concomitant clogging of pore space. In this study, a circulation-enhanced EK (CEEK) system is designed to neutralize the pH of the working solution and soils for avoiding the above problems. Experiments are conducted by controlling different voltage gradients, electrode materials, and electrode emplacement, respectively. According to the experimental results, the CEEK system could effectively stabilize the current and the pH of processing solution at a neutral range. The strength of voltage gradient is proportional to the current magnitude of the CEEK system. The graphite electrode for CEEK is the better choice than the metal electrodes because graphite electrodes can achieve the lower electricity consumption. The electrode installed in the reservoir without attachment on soils can decrease the pH deviation of the soil matrix.
电动修复技术（EK）是一种土壤修复技术。然而，阳极处水电解产生的酸会导致土壤酸化，这可能会破坏土壤成分，并降低污染物去除效率。阴极处产生的碱前沿的形成会导致金属氢氧化物沉淀，并伴随孔隙空间堵塞。在本研究中，设计了一种循环增强型电动修复（CEEK）系统来中和工作溶液和土壤的pH值，以避免上述问题。分别通过控制不同的电压梯度、电极材料和电极位置进行实验。根据实验结果，CEEK系统能够有效地将处理溶液的电流和pH值稳定在中性范围内。电压梯度强度与CEEK系统的电流大小成正比。用于CEEK的石墨电极比金属电极是更好的选择，因为石墨电极可以实现更低的电耗。安装在储液器中且不附着在土壤上的电极可以降低土壤基质的pH偏差。
