Jiradecha Chatdanai, Urgun-Demirtas Meltem, Pagilla Krishna
Chemical and Environmental Engineering Department, Illinois Institute of Technology, Chicago, 606016, USA.
J Hazard Mater. 2006 Aug 10;136(1):61-7. doi: 10.1016/j.jhazmat.2005.11.014. Epub 2005 Dec 15.
Electrokinetic soil remediation has been proven to remove heavy metals and polar organics from low hydraulic conductivity subsurface environment. In this study, carboxymethyl-beta-cyclodextrin (CMCD) was used as a carrier to assist electrokinetic treatment for removal of low polarity organic contaminants from soils (2.2% organic carbon content). Naphthalene and 2,4-dinitrotoluene (2,4-DNT) were selected as the test compounds. The results from columns experiments showed that 46 and 43% of naphthalene and 2,4-DNT, respectively, were removed using 0.01 N NaNO(3) flushing solution with 40 V electrical potential while 70 and 72% of naphthalene and 2,4-DNT were removed using 2 g/L CMCD solution. Naphthalene and 2,4-DNT removal was enhanced to 83 and 89%, respectively, by using 2 g/L CMCD with 40 V electrical potential. Findings from this study also demonstrated that cyclodextrin assisted electrokinetics can enhance the removal rate of naphthalene and 2,4-DNT. Electric potential applied has more influence on the contaminant removal than the amount of CMCD used. Higher voltage application caused increase in the removal rate of naphthalene and 2,4-DNT, and appeared to be one of the critical factors in obtaining higher contaminant removal while increasing CMCD solution concentration above 2 g/L appeared to have little effect on the contaminant removal.
电动土壤修复已被证明可从低水力传导率的地下环境中去除重金属和极性有机物。在本研究中，羧甲基-β-环糊精（CMCD）被用作载体，辅助电动处理以从土壤（有机碳含量为2.2%）中去除低极性有机污染物。选择萘和2,4-二硝基甲苯（2,4-DNT）作为测试化合物。柱实验结果表明，使用40 V电势的0.01 N NaNO₃冲洗液时，萘和2,4-DNT的去除率分别为46%和43%，而使用2 g/L CMCD溶液时，萘和2,4-DNT的去除率分别为70%和72%。通过使用2 g/L CMCD和40 V电势，萘和2,4-DNT的去除率分别提高到83%和89%。本研究的结果还表明，环糊精辅助电动技术可提高萘和2,4-DNT的去除率。施加的电势对污染物去除的影响比所用CMCD的量更大。施加更高的电压会导致萘和2,4-DNT的去除率增加，并且似乎是实现更高污染物去除率的关键因素之一，而将CMCD溶液浓度提高到2 g/L以上对污染物去除似乎影响不大。
