16s-RNA sequencing analysis of the influence of UV radiation on the metabolic pathways of pollutants in the A2O process
It is currently known that the addition of ultraviolet (UV) radiation can effectively improve the removal efficiency of pollutants in sewage, but there is little knowledge about the metabolism of carbon, nitrogen and phosphorus in this process. In order to reveal the carbon, nitrogen and phosphorus metabolism pathways of activated sludge (AS) with UV radiation, five different doses of UV radiation were added to the AS. Using 16s-RNA sequencing and chemical analysis methods, through a 50-day culture study, the AS microbial community and enzyme gene changes were studied. The results show that a proper amount of UV radiation is helpful to the removal of nitrogen, and a large dose of UV radiation is not conducive to the removal of pollutants. Different doses of UV radiation can significantly change the microbial community structure of AS and the abundance of key functional enzymes. Among AS to which UV radiation is added, Bacteroidetes, Proteobacteria, Actinobacteria and Firmicutes are the advantages. 16s-RNA sequencing analysis shows that UV radiation can promote the formation of phosphoric acid, glycerol, acetyl and glyceraldehyde in carbon metabolism, as well as the decomposition of amino acids and peptide bond cleavage in nitrogen metabolism, and it is most obvious under 10 minutes of UV radiation, But UV radiation has an inhibitory effect on the pathways of specific enzyme gene function. UV radiation shows greater inhibition of phosphorus metabolism, and the addition of UV radiation cannot effectively increase the removal rate of TP.