Abstract
Whereas the use of recycled municipal wastewater has been practiced for a number of years, the use of recycled wastewater in the petroleum industry has been limited. Nonetheless, tightening effluent regulations and diminishing freshwater supplies have generated interest in the treatment of refinery wastewaters for reuse. Historically, refinery wastewater has been treated to various degrees of effluent quality by means of oil/water separation and biological secondary treatment. This level of treatment was not able to produce a treated effluent that is suitable for reuse in the refinery process. Recent developments in membrane technology have enabled refineries to implement treatment strategies that allow process wastewater to be treated and reused. Applications of the reuse within the refinery include cooling tower make-up and boiler feed water.
An added benefit of membrane technology is the flexibility of how it can be implemented into greenfield sites or retrofitted into existing plants. Membrane bioreactors eliminate the need for a secondary clarification step and ensure a minimal footprint. Tertiary filtration is an excellent polishing step for existing plants that need further treatment or the reliability that membranes are able to guarantee. Regardless of which configuration is chosen, the end result is a high quality effluent that is suitable for re-use, including feed to reverse osmosis.
Case studies of full-scale systems operating with reinforced immersed hollow fiber membrane technology are included to provide an example of applications where refineries have employed this technology to achieve their treatment objectives and reuse goals.
