电极材料对电动修复尾矿周边铅污染土壤的影响研究

Effects of Electrode Material on Electrode Remediation of Lead-contaminated Soil Near A Mine Tailing

影响土壤电动修复效率的因素很多,包括土壤类型、污染物性质、电压和电流大小、洗脱液组成和性质、电极材料和结构等。但很少有文献报道不同电极材料对电动修复土壤重金属污染的效率影响,文章采用不同电极材料(石墨、不锈钢和钛板)对尾矿附近的土壤进行电动修复,研究了修复效率及土壤p H随时间的变化情况。当电场强度为1 V/cm,采用石墨电极电动修复48 h总铅的去除效率为77%,不锈钢电极和钛电极的修复效率分别为64%和54%。石墨电极去除效率的提高归因于相比于不锈钢电极和钛电极,石墨电极提供更多的电子传递所需的活性界面。

To enhance the EK remediation,many factors should be considered. First of all,it is important to select a good electrode material to increase the active sites because the electrode directly interacts with the soil to carry heavy metals out into the pore solution. Therefore,the electrode material is related to the efficiency of EK remediation. In this work,the effects of three different electrode materials（ graphite,stainless steel,titanium plate） on the removal of lead-contaminated soil near a mine tailing by EK remediation were studied in detail,with the purpose of improving the efficiency of EK remediation. The variations in removal efficiency and soil p H with treatment time were determined. The removal efficiency of lead reached a maximum of 77%when using a voltage gradient of 1 V / cm and a treatment time 48 h with the graphite electrode. When using a stainless steel electrode,lead removal efficiency was 64%,and 54% of total Pb could be removed with a titanium plate electrode. The improved removal efficiency was attributed to the more active sites for transfer of electrons provided by the graphite electrode,compared to the stainless steel and titanium plate electrode.