Performances of a hybrid adsorption/submerged membrane biological process for toxic waste removal

This study focuses on a hybrid process, which combines adsorption on powdered activated carbon (PAC), membrane separation using immersed hollow fibers and biological activity. The first part shows that PAC addition in a complex system (containing dissolved molecules and biological particles) can reduce membrane fouling. In that system, DMP removal is function of the activated carbon concentration. Then, respirometric experiments allowed comparison of toxic sensitivity and biological degradation of different bioreactors (membrane bioreactor (MBR), adsorptive membrane bioreactor (PAC-MBR) and classical activated sludge bioreactor (AS)). Results point out that MBR sludge is less sensitive to the toxic than the AS. For high toxic concentration, PAC addition in the MBR decreases rapidly the toxic concentration under the EC50 in the bioreactor, which allows a better biodegradation of the toxic compound. DMP assimilation is completed more rapidly with the PAC-MBR than the MBR.