A combination of solvent extraction and freeze thaw for oil recovery from petroleum refinery wastewater treatment pond sludge

作者：Hu, Guangji; Li, Jianbing^*; Hou, Haobo

来源：Journal of Hazardous Materials, 2015, 283: 832-840.

DOI：10.1016/j.jhazmat.2014.10.028

• Freeze thaw
• Oil recovery
• Oily sludge
• Petroleum hydrocarbons
• Solvent extraction

A combination of solvent extraction and freeze thaw was examined for recovering oil from the high-moisture petroleum refinery wastewater treatment pond sludge. Five solvents including cyclohexane (CHX), dichloromethane (DCM), methyl ethyl ketone (MEK), ethyl acetate (EA), and 2-propanol (2-Pro) were examined. It was found that these solvents except 2-Pro showed a promising oil recovery rate of about 40%, but the recycling of DCM solvent after oil extraction was quite low. Three solvents (CHX, MEK and EA) were then selected for examining the effect of freeze/thaw treatment on improving the quality of recovered oil. This treatment increased the total petroleum hydrocarbon (TPH) content in recovered oil from about 40% to 60% for both MEK and EA extractions, but little effect was observed for CHX extraction. Although the solid residue after oil recovery had a significantly decreased TPH content, a high concentration of heavy metals was observed, indicating that this residue may require proper management. In general, the combination of solvent extraction with freeze/thaw is effective for high-moisture oily hazardous waste treatment.

• 出版日期2015-2-11
• 单位温州大学; 武汉大学