title: Biofouling potential reductions using a membrane hybrid system as a pre-treatment to seawater reverse osmosis.
abstract: Biofouling on reverse osmosis (RO) membranes is the most serious problem which affects desalination process efficiency and increases operation cost. The biofouling cannot be effectively removed by the conventional pre-treatment traditionally used in desalination plants. Hybrid membrane systems coupling the adsorption and/or coagulation with low-pressure membranes can be a sustainable pre-treatment in reducing membrane fouling and at the same time improving the feed water quality to the seawater reverse osmosis. The addition of powder activated carbon (PAC) of 1.5 g/L into submerged membrane system could help to remove significant amount of both hydrophobic compounds (81.4%) and hydrophilic compounds (73.3%). When this submerged membrane adsorption hybrid system (SMAHS) was combined with FeCl(3) coagulation of 0.5 mg of Fe(3+)/L, dissolved organic carbon removal efficiency was excellent even with lower dose of PAC (0.5 g/L). Detailed microbial studies conducted with the SMAHS and the submerged membrane coagulation-adsorption hybrid system (SMCAHS) showed that these hybrid systems can significantly remove the total bacteria which contain also live cells. As a result, microbial adenosine triphosphate (ATP) as well as total ATP concentrations in treated seawater and foulants was considerably decreased. The bacteria number in feed water prior to RO reduced from 5.10E(+06) cells/mL to 3.10E(+03) cells/mL and 9.30E(+03) cells/mL after SMAHS and SMCAHS were applied as pre-treatment, respectively. These led to a significant reduction of assimilable organic carbon (AOC) by 10.1 μg/L acetate-C when SMCAHS was used as a pre-treatment after 45-h RO operation. In this study, AOC method was modified to measure the growth of bacteria in seawater by using the Pseudomonas P.60 strain.
authors.affiliation: Faculty of Engineering and IT, University of Technology, Sydney (UTS), P.O. Box 123, Broadway, NSW 2007, Sydney, Australia.
authors.forename: Sanghyun
authors.initials: S
authors.lastname: Jeong
authors.forename: Lan Hee
authors.initials: LH
authors.lastname: Kim
authors.forename: Sung-Jo
authors.initials: SJ
authors.lastname: Kim
authors.forename: Tien Vinh
authors.initials: TV
authors.lastname: Nguyen
authors.forename: Saravanamuthu
authors.initials: S
authors.lastname: Vigneswaran
authors.forename: In S
authors.initials: IS
authors.lastname: Kim
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D002853:Chromatography, Liquid; D008567:Membranes, Artificial; D009995:Osmosis; D012623:Seawater; D014871:Water Microbiology
chemical_list: D008567:Membranes, Artificial; D000255:Adenosine Triphosphate