许多污染场地都呈现重金属和有机污染物叠加的趋势,给修复带来了困难和挑战。以红壤为供试土壤,以铜和芘为代表性污染物,研究了添加表面活性剂羟丙基-β-环糊精(HPCD)和氧化剂H2O2对电动修复该复合污染土壤的影响,其目的是实现重金属和有机污染物的同时去除。结果表明,在所有的处理中,芘和铜都有向阴极迁移的趋势;当提高土柱的pH时降低了芘的氧化和降解,同时也阻碍了土壤中铜的迁移和去除;阳极加10%HPCD,阴极控制酸性条件pH3.5有助于土壤中污染物的解吸和迁移,芘和铜的去除率分别可达到51.3%和80.5%;由于H2O2的不稳定性,添加6%H2O2并未明显提高芘和铜的去除率。
Thousands of sites are contaminated with both heavy metals and organic compounds,which brought the difficulties and challenges to soil remediation.Previous studies had shown that electrokinetic(EK)remediation technology has potential to remove heavy metals and organic compounds simultaneously.In this paper,red soil was selected as a test soil and it was spiked with pyrene and copper at a concentration of 500 mg·kg-1 to simulate typical compound pollutants.The impact of the biosurfactant hydroxypropyl-β-cyclodextrin(HPCD)and oxidant H2O2 on the EK remediation of compound polluted soil with pH control was studied.A voltage gradient of 1 V·cm-1 was applied for all the tests of 15 days duration.In all the tests,both pyrene and copper had the trend of migrating towards the cathode.The results showed that increasing soil pH reduced the oxidation and degradation of pyrene and hindered the removal of copper.The treatment of 10% HPCD and controlling catholyte pH at 3.5 was efficient for the desorption and migration of contaminants,and the removal rate of pyrene and copper reached 51.3% and 80.5%,respectively.The use of 6% H2O2 was found to be ineffective for the removal of pyrene and copper because of the instabilities of H2O2.The increase of H2O2 concentration and dose could be considered to increase the removal efficiency of PAHs.