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

Abstract

Due to the low efficiency and high energy consumption of conventional rural wastewater bio-ecological processes, 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 communities 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, adsorption, 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 partitioning 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.