Evaluation of different structures of moving bed biofilm reactors (MBBR) for synthetic wastewater treatment

Abstract

Performance of three different structures of moving bed biofilm reactors (MBBR) treating synthetic wastewater was evaluated. The three systems were operated under the same conditions of dissolved oxygen (DO) 3 mg/L at 26 °C. The effluent of chemical oxygen demand (COD) decreased from 111.6 mg/L in reactor 1 (R1), 128.8 mg/L in reactor 2 (R2), and 154.5 mg/L in reactor 3 (R3), to less than 100 mg/L, respectively, with concentration of influent NH4+-N rising from 30 mg/L to 50 mg/L. The concentration of effluent NH4+-N for R1, R2 and R3 were close to 2 mg/L, 4 mg/L and 5 mg/L, respectively. The highest TN removal rate in R1 achieved average 84.4 %, which was 6.0 % and 9.7 % higher than those of R2 and R3, respectively. R1 with two baffles in it exhibited well fluidization and abundant microbes growing on carrier.