PROCESS FOR REMOVING ORGANIC AND INORGANIC CONTAMINANTS FROM REFINERY WASTEWATER STREAMS EMPLOYING ULTRAFILTRATION AND REVERSE OSMOSIS

摘要

A process for removing soluble and insoluble organic and inorganic contaminants from refinery wastewater streams employing ultrafiltration and reverse osmosis is provided. The process comprises: (a) passing the refinery wastewater stream into contact with the high pressure side of an ultrafiltration membrane to remove insoluble contaminants present therein and recover from the low pressure side of the ultrafiltration membrane an ultrafiltration permeate; (b) passing the ultrafiltration permeate through a sequential softening system to remove divalent and trivalent metal cations present therein and provide a reverse osmosis feedwater; (c) subjecting the reverse osmosis feedwater to a pH adjustment to stabilize the solubility of the soluble organic contaminants and provide a pH adjusted reverse osmosis feedwater; and, (d) passing the pH adjusted reverse osmosis feedwater into contact with the high pressure side of a reverse osmosis membrane to remove soluble contaminants present therein and recover from the low pressure side of the reverse osmosis membrane a reverse osmosis permeate having a reduced concentration of soluble and insoluble organic and inorganic contaminants.