Hybrid membrane filtration process for leachate treatment

A hybrid technology known as the ultrafiltration-biologically active carbon (UF-BAC) process that amalgamates adsorption, biodegradation and membrane filtration is found to be highly efficient for treatment of landfill leachates. The process employs bioactive powdered activated carbon (PAC) with a leachate-acclimated microbial culture for the simultaneous sorption and biodegradation of organic constituents. Tubular cross-flow ultrafiltration membrane modules separate out colloids and microorganisms, and a high quality permeate is obtained. Batch biokinetic studies were performed for the two leachates to evaluate their extent of biodegradability and biodegradation kinetics. The process efficiencies for both leachates were in the range of 95-98% in terms of TOC removal, and exceeded 97% for specific organic pollutants. The UF-BAC process compared well with the PACT process in terms of organic removal, and produced higher quality effluent in terms of suspended solids (100% removal). The study demonstrated that addition of 1% PAC mitigated permeate flux deterioration attributed to membrane fouling and concentration polarization, and enhanced permeate transport. Possible mechanisms for flux amelioration are discussed. Copyright (C) 1996 Elsevier Science Ltd