Membrane operations

The success of any industrial pretreatment program is dependent on correct choice of technology and management. The rapid growth in the industrial sector has increased the mass of toxic and hazardous pollutants to the municipal wastewater treatment works. This may again inhibit the conventional biological treatment processes. Membrane separation is in this context a physical pretreatment process which splits the now of water in two; a less toxic permeate and a more concentrated retentate. Typically, the volume reduction is one order of magnitude from the feedflow to the retentate. Engineering contractors in general do not possess proper knowledge of membrane technology to convincingly include membranes as a viable process option in design of pre-treatment systems. Attractive features of membranes are low weight and space requirements without use of chemicals. Moreover, the equipment is modular and can be scaled up or operated at partial capacity. The paper documents examples of accumulated field experiences with the intention to prove that membrane separation is a mature technology for the industry to utilize and for the engineering contractor to master. Also, the paper conveys information pertinent to advances in membrane separation to better enable academia to adjust curricula to meet industrial demands for separation engineers. The challenge is to pick the right membrane for a specific wastewater and couple the membrane to compatable auxiliary equipment such as pumps, pipes, valves and meters. (C) 1997 IAWQ. Published by Elsevier Science Ltd.