Characteristics of the community-structure of A²O processes under different dissolved oxygen conditions in plateau areas

Abstract

This study conducted a Pilot-Scale Anaerobic-Anoxic-Aerobic Process (A2O) experiment in a highland city of Linzhi. Four Dissolved oxygen (DO) working conditions of 2.0, 1.5, 1.0, and 0.5 mg/L was designed in this experiment. The 16SrRNA gene sequencing was performed on sludge from the anaerobic, anoxic and aerobic tanks. Through the composition analysis of sludge on Phylum, Class and Genus level, it can be found that the number of bacterial community at each level of the bacterial community was relatively low. Indicators of community richness, community evenness and community diversity were relatively low compared to other regions. The bacterial communities at different levels are significantly different from the reported dominant community and abundance. Correlation analysis between environmental factors and bacterial community structure proved that DO had significant correlation with bacterial community structure (P<0.05). The removal rates of the total phosphorous (TP), Total nitrogen (TN), Ammonia nitrogen (NH3-N) and Chemical Oxygen Demand (COD) were all affected by the sample communities structure. The composition of the bacterial community structure included nitrifying bacteria, denitrifying bacteria and polyphosphate-accumulating organisms, but the abundance was relatively low. The results also showed that the dominant community in different DO conditions and different reactors has large differences.

Effects of ultraviolet radiation on the community structure and metabolic pathways of A2O process in Plateau environment

“…23% are inhibited under UV irradiation except for 30 minutes, and Cyanoamino acid metabolism 0.2 1%～0.2 9% is strengthened under UV irradiation. With reference to the existing literature Hao et al 2021 , the phosphorus metabolism pathway mainly includes Oxidative phosphorylation map00190 and Pentose phosphate pathway map00030 . The Pentose phosphate pathway map00030 participates in both carbon metabolism and phosphorus metabolism, so it is no longer to analyze its metabolic pathway, only Oxidative phosphorylation map00190 is analyzed, and its relative abundance is shown in Fig.…”

The study on the changing pattern of microbial community function and phenotypes in anaerobic–anoxic–oxic (A2O) process under the influence of temperatures in plateau habitats

“…In recent years, studies related to the microbial community of domestic wastewater treated by the A 2 O process have also appeared in the plateau region of Tibet, which mainly focuses on the relevant personnel of our group. 22,23 Meanwhile, we based on Illumina MiSeq high-throughput sequencing technology and have predicted the function of the microbial community by PICRUSt in combination with the metabolic processes of pollutant decomposition, adsorption and transformation in wastewater. The structure and abundance of functional proteins, functional enzymes and functional genes of microbial communities in the activated sludge of the A 2 O process were investigated, and the functional modules and metabolic pathways of pollutants in the C, N and P were resolved.…”

Effects of ultraviolet radiation on the community structure and metabolic pathways of A2O process at Plateau environment

“…Tibet is located in the southwestern of the Qinghai-Tibet Plateau, with an average elevation of more than 4000meters , and is known as the roof of the world. High altitude creates unique habitat conditions of high cold, low air pressure and strong ultraviolet(UV) rays, which have a greater impact on the operation of sewage treatment, which is manifested by poor nitrogen and phosphorus removal effects and even sewage treatment that cannot meet the sewage discharge standards (Zong et al, 2020;Li et al, 2021).…”