Physico-chemical pretreatment to seawater reverse osmosis (SWRO): organic characterization and membrane autopsy

In this study, different pretreatment methods such as microfiltration (MF), Ultrafiltration (UF), nanofiltration (NF), powdered activated carbon (PAC) adsorption and ferric chloride (FeCl(3)) flocculation were evaluated in terms of their capability in removing seawater organic matter (SWOM) and the characteristics of the foulants on the seawater reverse osmosis (SWRO) membranes. A detailed experiment with a crossflow SWRO filtration unit was conducted with SR membrane (MWCO 100 Da) at 60 bar with seawater (conductivity = 48.9 mS/cm) drawn from south-western Korea. The SWOM removal by UF, NF, PAC adsorption and FeCl(3) flocculation was 20.3, 28.9, 46 and 23.3%, respectively. SWOM used in this study predominantly consisted of small size organic matter (