A novel enhanced bio-ecological combined reactor for rural wastewater treatment: Operational performance and microbial communities

Due to the low efficiency and high energy consumption of conventional rural wastewater bio-ecological pro-cesses, a novel multi-compartment enhanced hydrolysis-composite media ecological filter bed combined reactor (EH-CMEFB) was constructed. The combined reactor's start-up, operational performance, and microbial com-munities were studied for low-strength rural wastewater treatment. The results showed that EH-CMEFB could achieve synchronous start-up quickly, with the average removal efficiencies of chemical oxygen demand (COD) and total phosphorus (TP) reaching 87.20 % and 87.98 %, respectively, during the stable period. The multi-compartment partition hydrolysis of the enhanced hydrolysis unit (EH) increased the hydrolysis of tryptophan-like protein and soluble microbial products (SMPs), thereby improving the biodegradability of wastewater. The synergistic effect of Acorus calamus root and filling materials on pollutant absorption, adsorp-tion, and precipitation in the composite media ecological filter bed (CMEFB) achieved the main removal of pollutants. High-throughput sequencing technology assessments indicated that the population and relative abundance of dominant functional bacteria in the different compartments of EH were different, and the parti-tioning hydrolysis function enhanced the hydrolysis of different types of pollutants in different compartments. This novel combined reactor has a competitive advantage in rural wastewater treatment owing to its economic benefits.