Effectiveness of ceramic ultrafiltration as pretreatment for seawater reverse osmosis

Abstract

The Gulf Cooperation Council (GCC) region's considerable reliance on seawater reverse osmosis (SWRO) for freshwater production is amplifying with increasing population and industrial growth. Nonetheless, harsh seawater conditions in the region coupled with ineffective pretreatment have triggered frequent SWRO plant shutdowns, premature RO membrane and cartridge filter replacements, and low plant availability. To improve plant performance and sustainability, an effective pretreatment is needed; a promising option is the use of ceramic membranes. To investigate their effectiveness for handling variable seawater conditions experienced in the region — specifically harmful algal blooms (HAB) — this work presents a pilot scale ceramic UF (CUF) pretreatment study. Operational reliability and treated water quality of CUF was evaluated against existing polymeric MF and UF pretreatment in adjacent SWRO plants. CUF operated at full capacity during HAB season, compared to 30–40 % reduction for the MF/UF plants. Furthermore, it produced superior permeate quality, despite variations in feedwater conditions — for instance, it removed over 5× more Dissolved Organic Carbon (DOC) and 1.5× more Transparent Exopolymer Particles (TEP) than the polymeric membranes. These results indicate the potential for CUF as an effective pretreatment for SWRO to minimize plant downtime and ensure consistent permeate quality during all seawater conditions.