Chen Colin S, Lai Yun-Wei, Tien Chien-Jung
Institute of Biotechnology, National Kaohsiung Normal University, 62, Shen-Chung Road, Yanchao, Kaohsiung 824, Taiwan.
Environ Pollut. 2008 Dec;156(3):988-96. doi: 10.1016/j.envpol.2008.05.012. Epub 2008 Jun 12.
Variability in gasoline-water partitioning of major aromatic constituents (benzene, toluene, ethylbenzene, and xylenes (BTEX)) and methyl tert-butyl ether (MTBE) were examined for regular and ethanol-blended gasolines. By use of a two-phase liquid-liquid equilibrium model, the distribution of nonpolar solutes between fuel phase and water was related to principles of equilibrium. The models derived using Raoult's law convention for activity coefficients and liquid solubility is presented. The observed inverse log-log linear dependence of K(fw) values on aqueous solubility, could be well predicted by assuming gasoline to be an ideal solvent mixture. Oxygenated additives (i.e., ethanol and MTBE), in the low percent range (below 5%), were shown to have minimal or negligible cosolvent effects on hydrocarbon partitioning. In the case of high fuel-to-water ratio (e.g., 1:1) or near contaminant source zone, the cosolvent effect of oxygenated gasoline with high content of ethanol (e.g., E85) will be environmentally significant.
研究了常规汽油和乙醇混合汽油中主要芳香族成分（苯、甲苯、乙苯和二甲苯（BTEX））以及甲基叔丁基醚（MTBE）在汽油-水分配中的变异性。通过使用两相液-液平衡模型，非极性溶质在燃料相和水之间的分布与平衡原理相关。给出了使用拉乌尔定律约定的活度系数和液体溶解度推导的模型。通过假设汽油为理想溶剂混合物，可以很好地预测观察到的K（fw）值对水溶解度的反对数-对数线性依赖性。低百分比范围（低于5%）的含氧添加剂（即乙醇和MTBE）对烃类分配的共溶剂效应极小或可忽略不计。在高燃料-水比（如1:1）或接近污染物源区的情况下，高乙醇含量的含氧汽油（如E85）的共溶剂效应在环境方面将具有重要意义。
