Characteristics of the community-structure of A2O processes under different ultraviolet conditions in plateau areas.
Description
In this study, a laboratory-scale A2O wastewater treatment was performed in Linzhi City at an altitude of 3,000 meters. The UV conditions were designed to include a total of five irradiation times of 0, 5, 10, 30, and 180 min with the goal of sterilizing anaerobic, anoxic and aerobic tanks. The sludge in the oxygen tank was sequenced using the 16SrRNA gene, and the colony composition of the phyla, classes, orders, families, genera, and species was analyzed. There were significant differences in the numbers of families, genera, and species (P≤0.05). The community richness, uniformity, diversity and other indicators differed to some degree compared with those of other regions. The analysis of composition of bacterial colonies revealed different levels. The significance test of the difference between the groups, the significance of the dominant species, and the mechanism of UV was analyzed. A CCA diagram was used to verify that UV is an important factor in the colony structure composition, and the correlation heatmap diagram was used to analyze the microorganisms that are significantly related to UV. A sample hierarchical cluster analysis showed that the time of UV exposure can be divided into two categories, and the effects of UV exposure increase sequentially as the time of exposure increases. A comprehensive analysis found that the enhancing and inhibitory effects of UV radiation affect the composition of the community structure in the sample, and the time of irradiation will affect the enhancing or inhibitory effect, that is, the community structure from the samples that were irradiated for different amounts of time differs greatly.