HOLLOW-FIBER BIOREACTOR FOR WASTE-WATER TREATMENT USING BUBBLELESS MEMBRANE AERATION

A laboratory scale hollow fibre membrane bioreactor which used bubblel ess membrane aeration was tested over 5 months for its ability to trea t synthetic sewage. A biofilm was grown on the surface of 280 mu m dia meter, gas permeable, sealed-end, polypropylene based fibres. The fibr e lumens were pressurized with pure oxygen and synthetic sewage was pu mped over the surface of the biofilm. At the highest volumetric COD (c hemical oxygen demand) loading of 8.94 kg/m(3)/d and a hydraulic reten tion time (HRT) of 36 min, 86% COD removal was achieved. A daily backw ash was necessary to prevent channelling. The oxygen transfer efficien cy was 100%.