Microorganism removal by conventional wastewater treatment process and membrane bioreactor

Efficacy of conventional wastewater treatment process and the membrane bioreactor technology in removing microbial pathogens was investigated. Total and fecal coliforms, somatic and F-specific coliphages were used as indicators of pathogenic bacteria and viruses. Up to 5.7 logs removal of coliforms and 5.5 logs of coliphages were observed in the conventional treatment process. Addition of chemical coagulants improved the efficacy of primary and secondary treatment for microorganism removal. Complete removal of coliforms and up to 5.8 logs removal of coliphages was observed in the MBR system. It was shown that the MBR system was capable of high removal of coliphages despite the variation in feed coliphage concentrations. The results of this study indicated that the MBR system can achieve better microbial removal by far fewer steps than the conventional treatment process with advanced tertiary treatment. The final effluent from both treatment processes have high quality which potentially can be reused.