Drinking water ultrafiltration: state of the art and experimental designs approach

Abstract

During cleaning steps, ultrafiltration membranes are mechanically and chemically stressed. This can result in membrane degradations, failures, and be shut down for membrane replacement and therefore affect the production rate of the process and its sustainability. These phenomena raise the problem of necessary optimization of the cleaning procedures that have to tackle simultaneously, the best cleaning efficiency and the less detrimental procedures for the membranes. Despite the fact that aging is becoming a major issue between end-users, membrane manufacturers, and chemical product suppliers, there is considerably less literature dedicated to membrane aging than to cleaning. First, this study briefly reviews articles dedicated to aging damages involved by NaOCl and commercial detergents (especially on polysulfone ultrafiltration membrane). Then, the present study details the innovative way setup: “Designs of experiments” is used to provide additional data that help with a thorough understanding of membrane aging. Thus, contrary to the accelerated aging approach that is commonly used in membrane-aging researches (concentration per time of contact: “c × t parameter”), designs of experiments were used to organize at best the aging experiments in order to achieve a relevant establishment of an aging pattern. Results show that this scientific approach provides a satisfying and reliable pattern to simulate membrane aging in function of the chosen chemical parameters.

Keywords:

• Experimental designs
• Polysulfone
• Aging
• Hypochlorite
• Commercial detergents

Acknowledgment

The authors are grateful to Serge Nitsche and Damien Chaudanson from the CINaM (Centre Interdisciplinaire des Nanosciences de Marseille) for their contribution in the experimental work.

Notes

Presented at the Conference on Membranes in Drinking and Industrial Water Production.Leeuwarden, The Netherlands, 10–12 September 2012.Organized by the European Desalination Society and Wetsus Centre for Sustainable Water Technology