Application of ultra-low concentrations of moderately-hydrophobic chitosan for ultrafiltration membrane fouling mitigation

Membrane fouling is a major obstacle for ultrafiltration (UF) in water treatment. Here, strategy mitigation, by applying an ultra-low concentration of moderately-hydrophobic chitosan (MHC) and using mildly elevated backwash temperature was proposed. The effects MHC type, concentration, were investigated continuous-flow tests PVDF hollow fiber membranes model raw water. Compared to the process without MHC, or with addition conventional coagulant polyaluminum chloride, MHC-based UF system under optimal conditions (MHC: 0.01 mg/L; temperature: 40 °C) demonstrated its superiority reduction ~55% reversible (RR) ~80% irreversible (IRR), as well improved effluent quality. A mechanistic study experimental analyses theoretical computations revealed that performance attributed following: (1) inhibited contaminant accumulation on membrane through hydrophilization surface-modification effect PVDF; (2) increased promoted release (by destabilizing cake layer structure) enhanced effect. additional cost dosing heating estimated at ~0.126 Chinese Yuan per ton produced water, environmental risk lower than treatment chemicals. In summary, has potential be feasible cost-effective approach control.