Phenolic wastewater treatment with ethers for removal and recovery of phenolics

摘要

Liquid-liquid extraction is used for the removal of phenolics from wastewater streams using an ether extractant which has a high partition coefficient and a low solubility in water such as methyl tertiary-butyl ether. The resulting phenolics-ether mixture may be separated by distillation or by the use of an aqueous solution of an alkali metal hydroxide to form a phenate in an aqueous phase and the ether in an organic phase followed by phase separation. Any ether dissolved in the wastewater is removed by distillation or the solubility of the ether in the wastewater is retarded by adding an aqueous alkali salt solution. In the distillation embodiment, an environmentally acceptable wastewater is readily obtained. In the salt treatment embodiment, the wastewater is suitable for treatment in the overall plant complex associated with the phenol/acetone plant.