Department of Chemical and Environmental Engineering, The University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan, Malaysia.
J Environ Sci (China). 2012;24(6):1064-75. doi: 10.1016/s1001-0742(11)60873-5.
Solubility data of recalcitrant contaminants in cosolvents is essential to determine their potential applications in enhanced soil remediation. The solubilities of phenanthrene, anthracene, fluoranthene and benzo[a]pyrene in ethyl lactate/water and ethanol/water mixtures were measured using equilibrium techniques. The cosolvency powers derived from solubility data were then applied to the model developed from the solvophobic approach to predict the capability of ethyl lactate and ethanol in enhancing the desorption of contaminants from soils. Both ethyl lactate and ethanol cosolvents were shown to be able to enhance the solubilisation of the tested four polycyclic aromatic hydrocarbons by > 4 orders of magnitude above the levels obtained with water alone. However, ethyl lactate demonstrated a greater capacity to enhance PAH solubility than ethanol. The cosolvency powers of ethyl lactate/water system obtained from the end-to-end slope (sigma) and the end-to-half slope (sigma0.5) of the solubilisation curve were 1.0-1.5 and 2.0-2.9 higher than ethanol/water system respectively. In line with this, ethyl lactate/water was demonstrated to enhance the desorption of contaminants from soil by 20%-37% and 18%-61% higher compared to ethanol/water system in low organic content and high organic content soils respectively, with a 2:1 (V/W) ratio of solution:soil and with cosolvent fraction as low as 0.4. With the exception of benzo[a]pyrene, the experimental desorption results agreed fairly with the predicted values, under an applied solution:soil ratio that was enough to hold the capacity of released contaminants.
在增强土壤修复中确定它们的潜在应用时，需要了解难溶性污染物在共溶剂中的溶解度数据。使用平衡技术测量了菲、蒽、荧蒽和苯并[a]芘在乳酸乙酯/水和乙醇/水混合物中的溶解度。然后，将溶解度数据得出的共溶能力应用于从疏溶剂理论发展而来的模型，以预测乳酸乙酯和乙醇增强污染物从土壤中解吸的能力。结果表明，乳酸乙酯和乙醇两种共溶剂都能够将测试的四种多环芳烃的溶解度提高 4 个数量级以上，远远超过单独用水的水平。然而，乳酸乙酯增强 PAH 溶解度的能力大于乙醇。从溶解度曲线的端到端斜率（sigma）和端到半斜率（sigma0.5）获得的乳酸乙酯/水系统的共溶能力分别比乙醇/水系统高 1.0-1.5 和 2.0-2.9。与此一致的是，与乙醇/水系统相比，乳酸乙酯/水在低有机含量和高有机含量土壤中分别将污染物的解吸提高了 20%-37%和 18%-61%，溶液：土壤的比例为 2:1，共溶剂分数低至 0.4。除苯并[a]芘外，实验解吸结果与预测值相当，在应用的溶液：土壤比足以保持释放污染物的能力。
