School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.
J Hazard Mater. 2011 Feb 15;186(1):533-9. doi: 10.1016/j.jhazmat.2010.11.041. Epub 2010 Nov 16.
The application of water washing technology for recycling an organic composite solvent consisting of hexane and pentane (4:1; TU-A solvent) was investigated for extracting total petroleum hydrocarbons (TPH) from contaminated soil. The effects of water volume, water temperature, washing time and initial concentration of solvent were evaluated using orthogonal experiments followed by single factor experiments. Our results showed that the water volume was a statistically significant factor influencing greatly the water washing efficiency. Although less important, the other three factors have all increased the efficacy of water washing treatment. Based on a treatment of 20 g of contaminated soil with a TPH concentration of 140 mg g(-1), optimal conditions were found to be at 40°C, 100 mL water, 5 min washing time and 660 mg g(-1) solvent. Semi-continuous water extraction method showed that the concentration of the composite solvent TU-A was reduced below 15 mg g(-1) d.w. soil with a recovery extraction efficiency >97%. This finding suggests that water washing is a promising technology for recycling solvent used in TPH extraction from contaminated soils.
研究了水洗技术在回收由正己烷和戊烷（4:1；TU-A 溶剂）组成的有机复合溶剂中的应用，该溶剂用于从污染土壤中提取总石油烃（TPH）。通过正交实验和单因素实验评估了水体积、水温、洗涤时间和溶剂初始浓度的影响。结果表明，水体积是一个对水洗效率有显著影响的统计因素。虽然其他三个因素不太重要，但它们都提高了水洗处理的效果。基于处理 20gTPH 浓度为 140mg/g 的污染土壤，最佳条件为 40°C、100mL 水、5min 洗涤时间和 660mg/g 溶剂。半连续水提取方法表明，复合溶剂 TU-A 的浓度在 40°C、100mL 水、5min 洗涤时间和 660mg/g 溶剂下可降至 15mg/g 以下，回收提取效率>97%。这一发现表明，水洗技术是从污染土壤中提取 TPH 时回收溶剂的一种很有前途的技术。
