Algal Blooms and Membrane Based Desalination Technology

This thesis addresses the need to study algal blooms and their impact on the operation of UF pre-treatment and SWRO systems. Theoretical and experimental studies were performed to characterise the properties and fouling propensity of transparent exopolymer particles (TEP) released by bloom-forming algae. A method to measure TEP down to 10 kDa size was developed and applied to assess the effectiveness of various pre-treatment processes in 5 RO plants. It was demonstrated that algal blooms can cause non-backwashable fouling in UF and can accelerate biological fouling in RO system. However, it is unlikely that algae themselves are the main cause of fouling but rather the TEPs which they produced. Both algae and TEPs can be effectively removed by UF pre-treatment before the SWRO system.