Preparation and surface modification of hollow fibre membranes for drinking water disinfection and water reclamation

Polysulphone hollow fibres were spun according to phase inversion process under different conditions by extrusion of dimethylformamide solution of the polymer through double orifice spinneret using water or water-DMF mixture as gelation medium. The membrane surface was modified by in situ interfacial polymerisation of m-phenylenediamine with trimesoyl chloride. The nominal molecular weight cut-off (MWCO) values of the virgin fibres were 44,000?94,000 g/mol, which were decreased to 10,000?14,000 g/mol upon surface modification. The contact angle of the virgin fibres was about 87° and was decreased to about 65° by surface modification. HF modules exhibited pure water fluxes of 40?70 litre/m²h at 25 psi, and 4?5 log reduction for microorganisms like cocci, E. coli and bacillus when tested with water containing 1010 cfu/ml of bacteria. Fibres were tested for the treatment of municipal sewage water for a period of 20 days and constant rejection-flux profile was observed throughout the period.