High pressure membrane foulants of seawater, brackish water and river water: origin assessed by sugar and bacteriohopanepolyol signatures

Abstract

The present work aimed to study the origin of foulant material recovered on membranes used in water treatment. Firstly, sugar signatures were assessed from the monosaccharide composition. As results were not conclusive, a statistical approach using discriminant analysis was applied to the sugar data set in order to predict the origin of the foulant material. Three groups of various origins (algal, microbial, continental dissolved organic matter) were used as sugar references for the prediction. The results of the computation showed that the origin of reverse osmosis (RO) seawater foulant material is influenced by both the location of the water sources and the season. RO brackish water and nanofiltration river water foulant materials had a terrestrial origin. Secondly, bacteriohopanepolyol signatures indicated that RO seawater foulant material had a marine signature, RO brackish water foulant material had both a marine and a terrestrial origin and the nanofiltration river water foulant material contained only a terrestrial signature.

Keywords:

• fouling
• membrane deposit
• reverse osmosis
• nanofiltration
• sugars
• bacteriohopanepolyol

Acknowledgements

The authors are grateful to Dr F. Monna for valuable discussion on discriminant analysis. They also thank CNRS (Centre National de la Recherche Scientifique) for financial support. Robert Gibson (Newcastle University) is thanked for technical assistance. The Science Research Infrastructure Fund (SRIF) from HEFCE is thanked for funding the purchase of the ThermoFinnigan LCQ ion trap mass spectrometer (Newcastle University).