PDF《焦化场地 PAHs 污染土壤的电动-化学氧化联合修复》

焦化工业是以煤炭为原料, 生产焦炭、 焦炉煤气和 炼焦化学产品的工艺过程, 其各个生产环节内化石燃料 的不完全燃烧及焦油、 煤气等化工产品的加工过程都会 产生大量具有 三致 作用的多环芳烃 (PAHs) [1-2] .

在 焦化厂多年生产过程中, 厂区土壤受到严重污染[3-5] , 多环芳烃浓度较高, 而且高环多环芳烃所占的比例较 大. 近年来, 随着我国城市化进程的加快, 许多位于城 区的焦化厂已停产搬迁, 搬迁后所遗留的土壤污染问 题日渐凸显, 土壤修复迫在眉睫. 因此, 寻找有效的焦 化场地多环芳烃污染土壤修复方法, 已成为研究者普 遍关注的问题. 摘要: 焦化场地土壤多环芳烃 (PAHs) 污染严重, 目前的修复技术都存在不同程度的弊端. 通过研究化学氧化、 电动及其联合技 术对焦化场地高浓度多环芳烃污染土壤的修复效果, 比较了两种技术组合方式对修复效果的影响.结果表明, 单一技术及联合 技术对焦化场地 PAHs 均有一定的去除效果.在单一技术处理中, 电动处理、 芬顿和活化过硫酸钠对多环芳烃的去除率分别为 24.86%、 10.27%和22.19%;

在联合技术处理中, 活化过硫酸钠-电动组合、 电动-活化过硫酸钠组合、 芬顿-电动组合和电动-芬顿 组合对多环芳烃的去除率分别为 49.65%、 41.73%、 36.72%和31.39%.电动-化学氧化联合技术对 PAHs 的去除效果较单一技术 提高了 6.53%~27.46%.两种技术的组合方式及氧化剂类型均对联合处理效果产生影响, 化学氧化-电动处理的多环芳烃去除率 较电动-化学氧化处理高 5.33%~7.92%, 其差异主要由化学氧化去除率差异所引起;

应用活化过硫酸钠试剂的组合对多环芳烃的 去除率高出应用芬顿试剂的组合 12.93%~10.34%. 经联合处理后, 污染物的残留量及毒性当量浓度均有不同程度降低, 说明电动- 化学氧化联合技术是一种有效的预处理方法. 关键词: 焦化土壤;

多环芳烃;

电动修复;

化学氧化;

联合处理 中图分类号: X53 文献标志码: A 文章编号: 1672-2043 (2014) 10-1904-08 doi:10.11654/jaes.2014.10.005 焦化场地 PAHs 污染土壤的电动-化学氧化联合修复 张海欧 1,

2 , 郭书海 1* , 李凤梅

1 , 吴波1(1.中国科学院沈阳应用生态研究所, 沈阳 110016;

2.中国科学院大学, 北京 100049) Remediation of PAHs Contaminated Soil at Coking Site by Integrated Electrokinetics and Chemical Oxidation ZHANG Hai-ou1,2 , GUO Shu-hai1* , LI Feng-mei1 , WU Bo1 (1.Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China;

2.University of Chinese Academy of Sciences, Bei原jing 100049, China) Abstract: Soils at coking sites have been heavily contaminated with PAHs. Currently there is lack of effective remediation techniques for PAHs-contaminated soils. In this study, the efficiencies of chemical oxidation and electrokinetics and their integration for remediating PAHs heavily contaminated soils from coking sites were evaluated in a laboratory-scale experiment. Removal rates of PAHs were 24.86%, 10.27% and 22.19%, respectively, in treatments of electrokinetics, Fenton and activated persulfate. However, higher removal rates of PAHs were achieved for activated persulfate-electrokinetics, electrokinetics-activated persulfate, Fenton-electrokinetics and electrokinetics-Fenton, which were 49.65%, 41.73%, 36.72% and 31.39%, respectively. Integrating electrokinetics and chemical oxidation further enhanced the re原moval rate of PAHs by 6.53%~27.46% compared to electrokinetics or chemical oxidation alone. The sequence of applying electrokinetics and chemical oxidants and oxidant types impacted on the PAHs removal efficiency. Chemical oxidation-electrokinetics removed 5.33%~ 7.92% more PAHs than electrokinetics-chemical oxidation did. Applying activated persulfate increased PAHs removal by 12.93%~10.34% compared to using Fenton. These results show that integration of electrokinetics and chemical oxidation could be a promising pre-treatment technique to remove the PAHs in highly contaminated soils efficiently and to alleviate the residual toxicity. Keywords: coking site soil;