Citation:
Guozhong Wu, Xingang Li, Frédéric Coulon, Hong Li, Jingyan Lian, Hong Sui, Recycling of solvent used in a solvent extraction of petroleum hydrocarbons
contaminated soil, Journal of Hazardous Materials, Volume 186, Issue 1, 15 February 2011, Pages 533-539.
Abstract:
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 20g of
contaminated soil with a TPH concentration of 140mgg(-1), optimal conditions
were found to be at 40°C, 100mL water, 5min washing time and 660mgg(-1) solvent.
Semi-continuous water extraction method showed that the concentration of the
composite solvent TU-A was reduced below 15mgg(-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
