ELECTROCHEMICAL COMBINED REMEDIATION OF CHROMIUM CONTAMINATED SOIL BASED ON STRENGTHENING BY ANODE CONSUMPTION
-
摘要: 为解决重金属污染土在电动法修复过程中存在的聚焦效应问题,提出了牺牲铁阳极的电化学联用修复技术。在传统电动修复方法基础上增加电解液净化循环装置,优化Cr(Ⅵ)还原及沉淀所需技术参数,并与传统电动修复技术进行对比,探讨其修复效果及适用性。结果表明:迁出的Cr(Ⅵ)可在Fe2+作用下被还原为Cr(Ⅲ)并沉淀,pH、电压梯度、电流密度、电极面积均会影响其反应速率,电极距离对反应速率无直接影响,主要影响电解功率。Cr(Ⅵ)还原-沉淀反应的最佳技术参数为:pH值5~6.5,电压梯度0.8 V/cm,电流密度>6.67 mA/cm2,电极面积90 cm2,电极距离15 cm;较传统电动修复技术,以牺牲阳极强化铬污染土的电化学联用修复技术中,土壤室不同点位的去除率波动范围在10%,最高点位的去除率提高近24%,达93.4%。靠近阳极附近土体中Cr(Ⅵ)去除率从0.24%提高到80.38%。以牺牲阳极强化污染土的电化学联用修复方法不仅有效解决了重金属迁移的聚焦问题,而且有助于促进土中重金属污染物的整体性迁出。Abstract: In order to solve the problem of focusing effect in the process of electrokinetic remediation of heavy mental contaminated soil, the electrochemical combined remediation technology at the expense of iron anode was proposed. Based on the traditional electric repair method, the combined remediation technology added the electrolyte purification circulation device and it optimized the technical parameters for the reduction and precipitation of Cr (Ⅵ). The remediation effect and applicability were evaluated by comparing with the traditional electric remediation technology. The results showed that:1) The removed Cr (Ⅵ) can be reduced to Cr (Ⅲ) and precipitated under the action of Fe2+, and the parameters of pH, voltage gradient, current density and electrode area all affected the reaction rate. Electrode distance had no direct impact on the reaction but reflected in the power of electrolysis. 2) The best technical parameters of Cr (Ⅵ) reduction-precipitation reaction were:pH value was 5~6.5, voltage gradient was 0.8 V/cm, current density was more than 6.67 mA/cm2, electrode area was 90 cm2, and electrode distance was 15 cm. 3) Compared with traditional electric remediation technology, the removal rate of different soil points fluctuated in the range of 10%, and the removal rate of highest point was increased by nearly 24% (nearly 93.4%) in the electrochemical combined remediation technology. Especially, the removal rate of chromium near anode increased from 0.24% to 80.38%. 4) The electrochemical combined remediation method based on strengthening by anode consumption could not only solve effectively the focus problem, but also help to promote the overall migration of heavy metal in contaminated soil.
-
Key words:
- soil remediation /
- heavy metal /
- electrochemical remediation /
- anode consumption method /
- chromium
-
环境保护部,国土资源部.全国土壤污染状况调查公报[R]. 2014-04-17. 尹贞,张钧超,廖书林,等.铬污染场地修复技术研究及应用[J].环境工程,2015,33(1):159-162. 秦樊鑫,魏朝富,李红梅.重金属污染土壤修复技术综述与展望[J].环境科学与技术,2015,38(增刊2):199-208. 樊霆,叶文玲,陈海燕,等.农田土壤重金属污染状况及修复技术研究[J].生态环境学报,2013, 22(10):1727-1736. SHARMA S, TIWARI S, HASAN A, et al. Recent advances in conventional and contemporary methods for remediation of heavy metal-contaminated soils[J]. 3 Biotech, 2018, 8(4):216. 周东美,邓昌芬.重金属污染土壤的电动修复技术研究进展[J].农业环境科学学报,2003,22(4):505-508. 李亚林,刘蕾,段万超,等.电动修复技术对土壤中镉迁移的影响[J].环境工程学报,2016,10(10):6021-6027. 侯隽,樊丽,周明远,等.电动及其联用技术修复复合污染土壤的研究现状[J].环境工程,2017,35(7):185-189. LI D, XIONG Z, NIE Y, et al. Near-anode focusing pHenomenon caused by the high anolyte concentration in the electrokinetic remediation of chromium (Ⅵ)-contaminated soil[J]. Journal of Hazardous Materials, 2012, 229/230:282-291. 牛媛媛. 铬污染土壤电动修复中聚焦带的形成及影响研究[D].重庆:重庆大学,2013. YAN Y J, XUE F J, MUHAMMAD F, et al. Application of iron-loaded activated carbon electrodes for electrokinetic remediation of chromium-contaminated soil in a three-dimensional electrode system[J]. Scientific Reports, 2018, 8(1):5753. 付融冰,刘芳,马晋,等.可渗透反应复合电极法对铬(Ⅵ)污染土壤的电动修复[J].环境科学,2012,33(1):280-285. XU Y F, XIA W, HOU H T, et al. Remediation of chromium-contaminated soil by electrokinetics and electrokinetics coupled with CaAl-LDH permeable reaction barrier[J]. Environmental Science and Pollution Research, 2017, 24(25):20479-20486. TANG J, HE J G, XIN X D, et al. Biosurfactants enhanced heavy metals removal from sludge in the electrokinetic treatment[J]. Chemical Engineering Journal, 2018, 334:2579-2592. 周东美,仓龙,邓昌芬.络合剂和酸度控制对土壤铬电动过程的影响[J].中国环境科学,2005,25(1):11-15. 周鸣,汤红妍,朱书法,等.EDTA强化电动力学修复重金属复合污染土壤[J].环境工程学报,2014,8(3):1197-1202. 胡静,李东,胡思扬,等.牺牲铁阳极法修复铬(Ⅵ)污染土壤实验研究[J].重庆工商大学学报(自然科学版),2017,34(4):95-100. KRCMAR D, VARGA N, PRICA M, et al. Application of hexagonal two dimensional electrokinetic system on the nickel contaminated sediment and modelling the transport behavior of nickel during electrokinetic treatment[J]. Separation and Purification Technology, 2018, 192:253-261. 孟凡生,王业耀.铬(Ⅵ)污染土壤电动修复影响因素研究[J].农业环境科学学报,2006,25(4):983-987. 中华人民共和国水利部.土工试验规程(SL 237-1999)[S].北京:中华水利水电出版社,1999. 生态环境部.土壤环境质量建设用地土壤污染风险管控标准(试行):GB 36600-2018[S]. 北京:中国环境出版社,2018. 国家环境保护总局. 土壤环境监测技术规范:HJ/T 166-2004[S]. 北京:中国环境出版社,2004. 耿淑英,付伟章,郑书联,等.皮革厂含铬污泥铬回收及资源化利用[J].环境工程学报,2017,11(6):3767-3772. 王明辉,晏波,麦戈,等.分步沉淀法处理酸性矿山废水[J].化工环保,2016,36(1):47-52.
点击查看大图
计量
- 文章访问数: 269
- HTML全文浏览量: 46
- PDF下载量: 6
- 被引次数: 0