Ahn C K, Kim Y M, Woo S H, Park J M
Department of Chemical Engineering, School of Environmental Science and Engineering, Pohang University of Science and Technology, San 31, Hyoja-Dong, Pohang 790-784, Republic of Korea.
J Hazard Mater. 2008 Jun 15;154(1-3):153-60. doi: 10.1016/j.jhazmat.2007.10.006. Epub 2007 Oct 7.
The performance of activated carbon in soil washing and subsequent selective adsorption for surfactant recovery from the washed solution was investigated. Sandy loam soil contaminated with phenanthrene at 200 mg kg(-1) was washed with four different nonionic surfactants: Tween 40, Tween 80, Brij 30 and Brij 35. The efficiency of soil washing was highest when using Brij 30 with the highest solubilizing ability for phenanthrene and low adsorption onto soil. In the selective adsorption step, surfactant recovery was quite effective for all surfactants ranging from 85.0 to 89.0% at 1 g L(-1) of activated carbon (Darco 20-40 mesh). Phenanthrene removal from the solution washed with Brij 30 was only 33.9%, even though it was 54.1-56.4% with other surfactants. The selectivity was larger than 7.02 except for Brij 30 (3.60). The overall performance considering both the washing and surfactant recovery step was effective when using Tween 80 and Brij 35. The results suggest that higher solubilizing ability of surfactants is a requirement for soil washing but causes negative effects on phenanthrene removal in the selective adsorption. Therefore, if a surfactant recovery process by selective adsorption is included in soil remediation by washing, the overall performance including the two steps should be considered for properly choosing the surfactant.
研究了活性炭在土壤洗涤及随后从洗涤液中选择性吸附以回收表面活性剂方面的性能。用四种不同的非离子表面活性剂：吐温40、吐温80、月桂醇聚醚30和月桂醇聚醚35对受200 mg kg(-1)菲污染的砂壤土进行洗涤。使用对菲增溶能力最强且在土壤上吸附量低的月桂醇聚醚30时，土壤洗涤效率最高。在选择性吸附步骤中，对于1 g L(-1)的活性炭（Darco 20 - 40目），所有表面活性剂的表面活性剂回收率都相当有效，范围在85.0%至89.0%之间。用月桂醇聚醚30洗涤的溶液中菲的去除率仅为33.9%，而用其他表面活性剂时为54.1% - 56.4%。除月桂醇聚醚30（3.60）外，选择性大于7.02。考虑洗涤和表面活性剂回收步骤，使用吐温80和月桂醇聚醚35时整体性能有效。结果表明，表面活性剂较高的增溶能力是土壤洗涤的必要条件，但在选择性吸附中会对菲的去除产生负面影响。因此，如果通过洗涤进行土壤修复时包括通过选择性吸附回收表面活性剂的过程，为正确选择表面活性剂应考虑包括这两个步骤的整体性能。
