Performance and microbial community in a constructed rapid infiltration system with hydrochar and coke as filler for advanced treatment of N, N-dimethylformamide

Abstract

In this study, the treatment of wastewater with N, N-dimethylformamide (DMF) was carried out by a constructed rapid infiltration system (CRIS). The decontamination efficiency of the system with different fillers was investigated and the microbial communities and metabolic pathway were also analyzed. It was indicated that the removal of COD and DMF in the hydrochar-coke group (RA) and coke group (RB) were 58.91–59.93 % and 71.89–51.46 %, respectively. Compared with the influent, the average NH3-N concentration in the effluent increased by 77.04 % and 55.09 %, and the average removal rate of NO3--N by the two group was 72.95 % and 62.04 %, respectively. The abundance of DMF-degrading Paracoccus (5.10 %, 21.01 %) in the hydrochar and coke layers in RA was higher than the coke layer of RB (0.44 %), indicating that hydrochar promoted the growth and propagation of DMF-degrading bacteria. Hydrochar promoted the expression of gene PFK (0.2113 %), GADPH (0.3038 %), IDH (0.1832 %) and MDH (0.1758 %). In nitrogen metabolism, the relative abundance of glutamine synthetase was the highest. This research provided a theoretical foundation and technical support for the treatment DMF wastewater by CRIS.