Insight into the performance and fouling characteristics of submerged ceramic membrane bioreactor in wastewater treatment

Submerged membrane bioreactor (SMBR) is a promising technology in municipal wastewater treatment, but the membrane fouling has restricted its development. In this study, an integrated submerged ceramic membrane bioreactor (C-SMBR) was constructed to treat domestic wastewater, and the characteristics of membrane fouling and the microbial community structure were investigated. The results showed that the average removal efficiencies of COD, TN, NH₄⁺-N reached 94.97%, 61.69% and 71.61% respectively, under different ammonia nitrogen loading rate (NLR). The increase of soluble microbial products (SMP) and extracellular polymeric substances (EPS) in the suspension jointly accelerated the membrane fouling process, resulting in an increase in the trans-membrane pressure (TMP), which led to membrane fouling. Microbial community structure analysis showed that the dominant phylum bacteria were Patescibacteria, Proteobacteria, Actinobacteria, Bacteroidota and Chloroflexi, and the dominant class bacteria were Saccharimonadia, γ-proteobacteria, Actinobacteria, Bacteroidia, Anaerolineae, α-proteobacteria, etc. In summary, the conditions, microbial information and membrane fouling characteristics of wastewater treated by C-SMBR obtained in this study can provide reference and data support for further promotion and improvement of the application of C-SMBR and membrane fouling control.