阴极电解液对Cd污染红壤电动修复的影响

发布时间：2018-01-10 10:21

本文关键词：阴极电解液对Cd污染红壤电动修复的影响　出处：《环境科学研究》2017年02期 　论文类型：期刊论文

【摘要】：针对土壤重金属电动修复过程中阴极电解室pH升高会对重金属的去除产生不利影响的问题,利用Fe~(3+)/Fe~(2+)、Cu~(2+)/Cu标准电极电位较高的优势,以人工模拟Cd污染红壤为研究对象,对不同阴极电解液〔Fe(NO_3)_3、CuSO_4、柠檬酸〕的电动修复效果进行系统分析.结果表明:分别将Fe(NO_3)_3、CuSO_4、柠檬酸加入阴极电解室中,pH均控制在2~3,电动修复10 d后发现,将Fe(NO_3)_3溶液、CuSO_4溶液和柠檬酸作为阴极电解液均可以有效控制阴极室的pH,CuSO_4溶液、柠檬酸的加入对土壤中Cd的去除效果较差,而且Cu~(2+)的加入增加了土壤重金属二次污染的风险.相对于CuSO_4、柠檬酸试验组,Fe(NO_3)_3试验组土壤中Cd的去除率较高(大于87.27%),Fe(NO_3)_3试验组对土壤中Cd的修复效果也最为明显,土壤中w(Cd)由阴极附近的75.95 mg/kg降至阳极附近的9.13 mg/kg.分析电动修复后各试验组中不同形态Cd在Cd总量中所占比例的分析,结果显示,w(弱酸提取态Cd)所占比例由初始的74.57%最高可达到92.69%〔Fe(NO_3)_3试验组〕,表明Fe(NO_3)_3的加入有助于促进土壤中Cd的迁移.研究显示,相比于CuSO_4溶液、柠檬酸,Fe(NO_3)_3溶液作为阴极电解液在控制阴极电解室pH升高的前提下,显著促进了土壤中Cd的解吸和迁移,并达到最佳修复效果.
[Abstract]:In order to solve the problem that the increase of pH in cathode electrolysis chamber will have adverse effects on the removal of heavy metals during the electrokinetic remediation of heavy metals in soil, the Fe~(3 / / Feb2 is used. The Cu~(2 / Cu standard electrode has the advantage of high potential. Taking the simulated cadmium contaminated red soil as the research object, the different cathodic electrolytes (FeNos / CUSO _ 4) have been studied for different cathodic electrolytes. The results showed that Fegno _ (Nos) _ 3s _ (3) Cuso _ 4 was added to the cathode electrolysis chamber and the pH value was controlled at 2 ~ (3). After 10 days of electric repair, it was found that Fe(NO_3)_3 solution, CuSO4 solution and citric acid as cathode electrolyte could effectively control the pH of CuSO4 solution in cathode chamber. The addition of citric acid to soil CD removal efficiency was poor, and the addition of Cu~(2) increased the risk of heavy metal secondary pollution. Compared with CuSO4, citric acid test group. The CD removal rate of Fe(NO_3)_3 group was higher than that of 87.27% (> 87.27%). The effect of CD remediation was also most obvious in the experimental group (> 87.27). In soil. From 75.95 mg/kg near the cathode to 9.13 mg / kg near the anode. The results showed that the proportion of weak acid extractable CdTe could reach 92.69% from the initial 74.57% to 92.69%. The results showed that the addition of Fe(NO_3)_3 could promote the migration of CD in soil. Fe(NO_3)_3 solution as cathode electrolyte can significantly promote the desorption and migration of CD in soil and achieve the best remediation effect under the condition of controlling the increase of pH in the cathodic electrolytic chamber.
【作者单位】：昆明理工大学材料科学与工程学院;锂离子电池及材料制备技术国家地方联合工程实验室;昆明理工大学冶金与能源工程学院;昆明理工大学环境科学与工程学院学院;
【基金】：云南省环境保护专项资金
【分类号】：X53
【正文快照】： Cd是土壤重金属污染的重要元素之一,含Cd污染物进入土壤会对土壤产生持久性污染,并对人类健康产生巨大危害[1-2].我国每年受重金属污染的粮食产量达1.2×107t,直接经济损失达200×108元,受Cd污染的耕地面积超过13×104hm2[3-5],因此土壤Cd污染问题亟待解决[6].目前,在治理土壤

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