Role of microbial communities on organic removal during petrochemical wastewater biological treatment with pure oxygen aeration

Pure oxygen aeration-activated sludge processes exhibit a better pollutant removal performance than the activated sludge systems with air aeration. The role of microbial community structure on system performance remains unclear in activated sludge system with pure oxygen aeration. Two activated sludge reactors with pure oxygen and air aeration were used to treat petrochemical wastewater treatment under different food-tomicroorganism (F/M) ratio conditions. The pure oxygen aeration reactor was more tolerant against unsteady F/M ratio conditions and had better aromatics' removal performance than the air aeration reactor. The results of microbial community structure showed that Proteobacteria and Bacteroidetes were the dominant phyla in both reactors. Although the richness and diversity of bacterial community under pure oxygen aeration was lower than that under air aeration, the chemoheterotrophic bacteria related to the stability of organic removal performance in the pure oxygen aeration reactor were more abundant than those in the air aeration reactor. The genera Hydrogenophaga and Acinetobacter responsible for aromatic compounds degradation were also enriched in the pure oxygen aeration reactor.

Automated summary

The pure oxygen aeration reactor showed better performance in handling unsteady F/M ratio conditions and removing aromatics compared to the air aeration reactor. The microbial community structure revealed that Proteobacteria and Bacteroidetes were dominant in both reactors, with chemoheterotrophic bacteria related to organic removal more abundant in the pure oxygen reactor.