Extraction of pentachlorophenol from soils using environmentally benign lactic acid solutions.
Extraction of pentachlorophenol from soils using environmentally benign lactic acid solutions.
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DOI：
10.1016/j.jhazmat.2009.09.046
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发表时间：
2010-02
影响因子：
13.6
通讯作者：
B. Subramanian;V. Namboodiri;A. Khodadoust;D. Dionysiou
中科院分区：
文献类型：
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作者：
B. Subramanian;V. Namboodiri;A. Khodadoust;D. Dionysiou
五氯苯酚（PCP）的土壤污染在地球仪中十分普遍。土壤洗涤/提取是去除这种化合物的常用技术。已经使用了几种土壤洗涤/提取溶液，但由于它们的生物降解性低，其中大多数具有在环境中持久性的问题。我们的目的是研究乳酸和水的混合溶液作为表面活性剂溶液或有机溶剂系统的潜在替代品，用于从三种土壤中去除五氯苯酚：蒙脱石、天然沉积物（含有机物）和不含有机物的相同沉积物（燃烧沉积物）。本研究包括最佳的乳酸浓度在水中的最大提取效率和线性解吸常数的测定，从三种土壤中的乳酸去除五氯酚。研究了土壤/沉积物有机质对萃取效率的影响。初步实验表明，24 h为最佳提取时间。蒙脱石和灼烧沉积物的萃取率分别为40-80%和90%以上。天然沉积物由于有机物的存在而表现出较低的五氯苯酚提取率，而点燃沉积物则获得了较高的解吸系数值（1.23 L/kg）。对于所有的土壤，在较高浓度的乳酸中观察到提取减少。土壤/沉积物的比表面积也是影响五氯苯酚提取的重要因素。
Soil contamination with pentachlorophenol (PCP) is widespread across the globe. Soil washing/extraction is a common technique to remove this compound. Several soil washing/extraction solutions have been used but a majority of them have the problem of persistence in the environment due to their low biodegradability. Our aim was to investigate mixed solutions of lactic acid and water as potential alternatives to surfactant solutions or organic solvent systems used for the removal of PCP from three soils: montmorillonite, a natural sediment (with organic matter), and the same sediment without organic matter (ignited sediment). This study included the optimization of the concentration of lactic acid in water for maximum extraction efficiency and the determination of linear desorption constants for removal of PCP from the three soils with lactic acid. The effect of soil/sediment organic matter on the extraction efficiency was also studied. Initial experiments showed that 24h was the optimum extraction time. High extraction efficiencies were obtained for montmorillonite (40–80%) and ignited sediment (∼90%). The natural sediment exhibited low PCP extraction due to presence of organic matter, while high desorption coefficient values (∼23L/kg) were obtained for the ignited sediment. For all soils, a decrease in extraction was observed at higher concentrations of lactic acid. The specific surface area of soil/sediment was also found to be an important factor affecting the extraction of PCP.