Treatment of oil-in-water Emulsions: Performance of a Modified Resin Bed Coalescer

摘要

Large amounts of oily wastewater is generated in process industries such as metallurgical, petrochemical and transportation industries and introduced into water body. The current treatment methods of wastewater containing emulsified oil remain unsatisfactory. The aim of this work is to assess the performance of a modified resin as filter media for the treatment of oil-in-water emulsions. The effect of operating conditions on the performance of the modified resin bed coalescer was investigated. Small amounts of quaternary ammonium (cetyltrimethyl-ammonium bromide) were grafted onto the resin, acting as demulsifier to achieve the emulsion breakdown because of the high stability of the emulsion. The influence of flow rate, bed height, temperature and the pH value of wastewater was studied. Experimental results show that several processes are involved in oil removal from oil-in-water emulsions, i.e. coalescence, adsorption or straining. More than 85% of oil content in the influent stream was removed. Experimental results show that modified resin bed coalescer is feasible to be used in the treatment of oil-in-water emulsions due to no chemicals added into the wastewater.