Development of a bioprocess combined with membrane technology for the treatment and recycling of textile effluent

A mixed culture of dye‐decolorising Pseudomonas spp. was immobilised on polyurethane foam, and used in a bench‐scale continuous culture bioreactor to treat textile effluent for colour removal. The provision of soluble wheat starch (0.2% w/v) to the culture medium promoted growth of biomass and enhanced decolorisation of effluent in the bioreactor. The bioprocess was further combined with membrane filtration technology to improve the quality of treated effluent. The treated effluent showed 90, 82 and 60% reduction in COD, BOD5 and toxicity levels, respectively, and had potential for re‐use in dyeing processes. The colour difference of the cotton fabrics dyed using the treated effluent samples compared to those dyed using normal supply water was found to be industrially acceptable. The described process could improve treatment efficiency and allow water recycling within the textile factory.