Surfactant enhanced remediation of cadmium contaminated soils
Surfactant enhanced remediation of cadmium contaminated soils
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DOI：
10.1016/s0273-1223(98)00235-2
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发表时间：
1998-01-01
影响因子：
2.7
通讯作者：
Lei, WG
中科院分区：
文献类型：
--
作者：
Doong, RA;Wu, YW;Lei, WG
研究了添加表面活性剂对镉污染土壤的修复效果，以确定最佳的表面活性剂强化修复体系。采用阴离子表面活性剂（十二烷基硫酸钠，SDS）、非离子表面活性剂（Triton X-100，TX 100）和阳离子表面活性剂（十六烷基三甲基溴化铵，CTAB）考察了表面活性剂的萃取效果。EDTA和二苯硫卡巴腙（DPC）也被添加到提高表面活性剂的萃取效率。此外，pH值的影响进行了检查，以确定最佳的表面活性剂系统。阴离子和非离子表面活性剂的加入均能提高镉、铅和锌的解吸率，而阳离子表面活性剂的加入则降低了重金属的解吸率。在临界胶束浓度（CMC）以下，解吸效率随表面活性剂浓度的增加而线性增加，在CMC以上，解吸效率保持相对恒定。EDTA的加入能显著提高重金属的解吸效率。阳离子表面活性剂;在酸性环境下，是一种比非离子和阴离子表面活性剂更有效的表面活性剂。表面活性剂/EDTA混合体系对重金属的解吸效率为Cd > Ph > Zn。但DPC的加入使重金属去除率降低了2 ~ 4倍。此外，增加pH值会降低非离子和阴离子表面活性剂的萃取能力。研究结果表明，在不同pH值条件下，通过选择合适的表面活性剂和络合剂的种类和浓度，表面活性剂和络合剂可以有效地作为镉污染土壤的化学改良剂。(C)1998年国际水咨委。出版社：Elsevier Science Ltd
An investigation involving the addition of surfactant to remediate cadmium-contaminated soils was performed to determine the optimal surfactant enhanced remediation system. Anionic (sodium dodecyl sulfate, SDS), nonionic (Triton X-100, TX100) and cationic (cetyltrimethylammonium bromide, CTAB) surfactants were used to elucidate the extraction efficiency of surfactant. EDTA and diphenylthiocarbazone (DPC) were also added to enhance the extraction efficiencies of surfactants. Moreover, the pH effect was examined to determine the optimal surfactant systems. The addition of anionic and nonionic surfactants can enhance the desorption rates of cadmium, lead and zinc, whereas the addition of cationic surfactant decreased the desorption efficiency of heavy metals. The desorption efficiency was found to increase linearly with the increasing surfactant concentration below critical micelle concentration (CMC) and remained relatively constant above the CMC. Moreover, the addition of EDTA can significantly enhance the desorption efficiency of heavy metals. Cationic surfactant was shown; to be a more effective surfactant than nonionic and anionic surfactants in extracting heavy metals under acidic environment. The desorption efficiency of heavy metal in the surfactant/EDTA mixture system was in the order of Cd > Ph > Zn. However, the addition of DPC lowered the heavy metal removals by 2 to 4 times. Also, increasing pH value can decrease the extraction capabilities of nonionic and anionic surfactants. The results of this study demonstrate that surfactant in combination with complexing agents can be effectively used as chemical amendments to flush cadmium-contaminated soil by proper selection of type and concentration of surfactant and complexing agent at different pH values. (C) 1998 IAWQ. Published by Elsevier Science Ltd.