A Modified Packed Anaerobic Baffled Reactor Based on Phase Separation for the Treatment of Decentralized Wastewater: Performance and Microbial Communities

Anaerobic baffled reactors (ABRs) play a vital role in wastewater treatment due to their stable performance. In this study, the aim was to evaluate the performance and relationship between the pollutant degradation and the microbial communities in each compartment of a modified packed anaerobic baffled reactor (MPABR)when treating decentralized wastewater. The removal efficiencies under different hydraulic retention times (HRTs), the characteristics of the organic matter and microbial communities in the different compartments were investigated. The relationship between the degradation of pollutants and the functional microbial communities was analysed. The maximum average removal efficiency of chemical oxygen demand (COD) reached 76.7%. Additionally, the maximum concentration of volatile fatty acids (VFAs) was 1.75 mmol.L-1 in MPABR-1. The excitation-emission matrix (EEM) fluorescence spectra showed that the main components of the dissolved organic matter (DOM) and the extracellular polymeric substances (EPS) were protein-like substances and soluble microbial products (SMPs), and their fluorescence intensities decreased gradually along the flow direction. The distributions and relative abundances of the dominant microbial communities were related to the degradation of pollutants.