Environmental Science Research Institute, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China.
J Hazard Mater. 2010 Apr 15;176(1-3):306-12. doi: 10.1016/j.jhazmat.2009.11.029. Epub 2009 Nov 13.
This work aimed to evaluate hydroxypropyl-beta-cyclodextrin (HPCD) enhanced electrokinetic (EK) remediation of aged sediment contaminated with hexachlorobenzene (HCB) and heavy metals (Zn and Ni) in bench-scale. Deionized water, 5 and 20% HPCD were used as anodic flushing solutions, respectively, with constant voltage gradient of 1.0 V cm(-1). The experimental results showed that HCB migration and removal from sediments was significantly affected by HPCD concentrations and cumulative electroosmotic flow (EOF). In test with deionized water, only 7% of HCB was removed with 4.0 pore volumes (PVs) of EOF, while 15-26% of HCB was removed with 2.5-4.5 PVs using 5% HPCD solution. With 20% HPCD solution, nearly 40% of HCB removal efficiency achieved with 2.6 PVs. For Zn and Ni, the mobilization was greatly dependent upon sediment pH. In all tests, heavy metals migrated from anode to cathode, and accumulated near cathode due to the high pH, with little removal efficiency. This study indicated that EK process combined with HPCD flushing and pH buffering was a good alternative for HCB removal from sediments, and other enhancement was needed for heavy metals removal.
本研究旨在评估羟丙基-β-环糊精（HPCD）增强电动修复技术在处理含有六氯苯（HCB）和重金属（Zn 和 Ni）的老化沉积物中的应用。本研究采用去离子水、5%和 20%的 HPCD 作为阳极冲洗液，施加 1.0 V cm(-1) 的恒定电压梯度。实验结果表明，HCB 的迁移和去除受 HPCD 浓度和累积电动渗流（EOF）的显著影响。在去离子水实验中，EOF 为 4.0 个孔隙体积（PV）时，仅去除了 7%的 HCB，而使用 5%HPCD 溶液时，EOF 为 2.5-4.5 PV 时，去除了 15-26%的 HCB。当使用 20%HPCD 溶液时，仅用 2.6 PV 即可实现近 40%的 HCB 去除效率。对于 Zn 和 Ni，其迁移率主要取决于沉积物的 pH 值。在所有实验中，重金属从阳极迁移到阴极，并因高 pH 值而在阴极附近积聚，去除效率较低。本研究表明，电动修复技术与 HPCD 冲洗和 pH 值缓冲相结合是一种从沉积物中去除 HCB 的有效替代方法，而对于重金属的去除则需要其他增强措施。
