A modified anaerobic baffled reactor for municipal wastewater treatment

A nine-chambered modified anaerobic baffled reactor (MABR) was developed to evaluate its suitability for the treatment of municipal wastewater and to establish the understanding of the relationship between reactor design and operational parameters. The paper presents the configuration of the MABR, its start-up, effect of variation of hydraulic retention time (HRT) on treatment efficiency, and performance evaluation of the MABR while treating the municipal wastewater. To assess the self-inoculation potential of the MABR, the start-up was carried out without seed sludge at a HRT of 6 d. An acclimatization curve was plotted and indicated that a start-up period of 90 d was required for the MABR. Reactor performance evaluation was carried out for 375 d at 11 different HRTs ranging from 6 d to 3 h. The HRT of 6 h was adjudged to be appropriate for this reactor configuration. At a HRT of 6 h, the efficiencies of reduction in suspended solids (SS), biochemical oxygen demand (BOD), and chemical oxygen demand (COD) were found to be 86%, 87% and 84% respectively. Specific biogas yield and methane content were found to be 0.34 m3CH4/KgCODr and 67% respectively. The study has evaluated the performance pattern of the MABR and identified it as a suitable reactor technology for municipal wastewater management in India.