Fouling propensity of forward osmosis: investigation of the slower flux decline phenomenon.
Forward Osmosis (FO) is a membrane process that uses the natural osmotic pressure of a concentrated draw solution to extract pure water from a feed stream. The attraction of the FO process is that it uses dense membranes, while operating at ambient pressure. This means that the FO process could potentially produce high quality water with lower energy consumption, as compared to the other desalination or reclamation processes. As FO does not entail the use of hydraulic pressure, FO has been hypothesized to have lower fouling propensity than pressure driven membrane processes. Membrane fouling has significant impact on the operational sustainability and economics of the process. This study examines the possible contributing factors to the slower flux decline observed in FO experiments based on a combined experimental and modelling approach. It was found that these factors could include low water fluxes, use of hydrophilic and smooth membranes, and the effect of internal concentration polarisation that is inherent of FO. It was also found that the transmission of draw solutes from the draw solution into the feed can have significant effect on FO performance.
Lay
Winson C L
WC
Singapore Membrane Technology Centre, Nanyang Technological University, Singapore 639798, Singapore.
Chong
Tzyy Haur
TH
Tang
Chuyang Y
CY
Fane
Anthony G
AG
Zhang
Jinsong
J
Liu
Yu
Y
D004867:Equipment Design; D008567:Membranes, Artificial; D009995:Osmosis; D009997:Osmotic Pressure; D010316:Particle Size; D010539:Permeability; D012492:Salts / Q000737:chemistry; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
D008567:Membranes, Artificial; D012492:Salts; D014874:Water Pollutants, Chemical; D014867:Water