Performance of aerobic granular sludge in different bioreactors

Abstract

Inoculated sludge from the Brewery wastewater treatment plant was cultured in a sequencing batch reactor (SBR). The granular sludge was then used to process the artificial simulation wastewater to compare the performance and efficiency of the granular sludge in organic matter removal by using SBR and granular membrane bioreactor (GMBR). Results showed that the granular sludge in the SBR exhibited desirable characteristics and good removal efficiency. The mixed liquor suspended solids (MLSS) and the sludge volume index (SVI) were approximately 2.56 g/L and 78.13 mL/g, respectively, and it exhibited a satisfactory settling ability. The removal efficiency of the resulting chemical oxygen demand (COD), NH3-N and total phosphorus (TP) reached 89.35%, 96.49% and 83.76%, respectively. The removal efficiency of both nitrate nitrogen and total nitrogen (TN) reached 90%. The performance of the granular sludge as well as the removal efficiency of the organic matter in the GMBR was subsequently observed. Results showed that the process influenced the characteristics and microbial biomass of the granular sludge. The SVI and the MLSS were about 175.82 mL/g and 1.14 g/L, respectively. The removal efficiency of COD and TP increased to 93.17% and 90.42%, respectively. The removal efficiency of NH3-N was slightly affected, whereas that of both nitrate nitrogen and TN increased to 95%. In this study, the physical properties and the removal efficiency of granular sludge in different bioreactors were compared. The comparison demonstrated that granulation membrane bioreactors perform more efficiently compared with SBR in wastewater treatment for organic matter removal.