Influence of commercial detergents on UF membrane ageing: Case of ă drinking water
Résumé
During cleaning steps, ultrafiltration membranes are mechanically and ă chemically stressed. This may result in membrane degradations and ă failures. In this paper, polysulfone membranes were used to evaluate ă membrane deteriorations by commercial detergents in static conditions. ă Ageing of the membrane was simulated by immersing samples in solutions ă containing commercial detergents with various concentrations, ă temperatures and times defined by experimental designs. Indeed, an ă innovative approach in the chemical membranes ageing researches, based ă on methodological tools, was used in order to achieve significant ageing ă experiments without using an accelerated ageing protocol. The ă macroscopic changes were monitored by permeability measurements and ă mechanical strength tests coupled with a microscopic characterization by ă ATR-FTIR and HRSEM. The present work details results obtained for three ă commercial detergents: an alkaline, an acidic and an enzymatic ă detergent. It was found that the detergents used in the industrial ă advised conditions (concentration, temperature and time of contact) were ă not detrimental for membrane properties (permeability and elongation at ă break) and so for the quality of the produced water. Over the industrial ă cumulated time of contact, different ageing effects can be observed and ă compared with the ones induced by NaOCl.