Membrane autopsies: helps to provide solutions to operational problems in reverse osmosis plants

Abstract

The problems of the need for water in the quantity and quality for the diverse uses that we require of it is one of the principal problems that we must address. More and more plants are installed for the production of water for potable, irrigation or industrial uses that employ membrane technologies, especially reverse osmosis. Moreover, with increasing frequency these techniques are also being employed in the recycling of waters from urban and industrial effluents. Paralleling the development of these techniques and their new applications is the need for advances in understanding of the processes that affect their functioning and yield. Any reverse osmosis installation will in the medium or long term encounter problems of membrane fouling that necessitate cleansing. The cleansing protocol depends on the type of deposit (biofilm, organic matter, inorganic deposits or natural colloids) present in the membranes, which makes its characterisation indispensable. A “membrane autopsy” combines different procedures of analysis and tests capable of revealing information relating to the nature of the deposits and other aspects that can be associated with deficiencies in the functioning of the installations. In this way we have a toolkit able to compile the data necessary for the planning of new guidelines for the management of installations that will minimise or delay the appearance of the problems detected.