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U.S. Department of Energy
Office of Scientific and Technical Information

Separation of free oil following coalescence

Technical Report ·
OSTI ID:6924433

Three processes are employed in the separation of oil from water or wastewater. These oil-water separation systems are commonly referred to as gravity separation, secondary de-oiling and tertiary polishing. Because of special problems created by stable oil-in-water emulsions, it has been necessary to develop special techniques for breaking these emulsions. To accomplish this task of destabilization, coalescence has gained considerable attention, and processes employing various coalescence techniques have become an integral part of most oily water separation processes. The study was conducted to design and evaluate various devices for separating free oil from water after coalescence has been achieved. Six separators were evaluated with emphasis on oil removal efficiency and headloss. The independent variables in this laboratory-scale research were hydraulic loading and influent oil concentration. The dependent variables included oil removal efficiency and headloss. All tests were conducted for six hours. Experimental results indicated that the Model I separator effectively removed the oil from water under low flow rate conditions. Similarly, the Model VI separator was more successful under high flow rates. For these tests it was possible to reduce the oil concentration from 50 mg/l in the influent to 1 mg/l in the effluent. This represents a removal of 98%. Coalescence was accomplished using a polyester mat and a flow rate of 10 gpm/ft/sup 2/.

Research Organization:
Texas Univ., Austin (USA). Center for Research in Water Resources
OSTI ID:
6924433
Report Number(s):
CRWR-143; EHE-77-01
Country of Publication:
United States
Language:
English