Microbial Communities In Biological Process For Coal Gasification Wastewater Treatment

China is facing environmental problems due to massive growth of coal gasification industries. Biological treatment process is the core process for coal gasification wastewater treatment, in which microbial communities play major role in pollutant removal. However, the microbial communities in biological process for coal gasification wastewater treatment remained elusive. Therefore, this research focused on microbial communities in two experimental systems(fixed carrier anoxic/oxic-MBR), which were tested for the optimization of treatment processes to provide an insight for the design and operation of biological processes for coal gasification wastewater treatment.Hence, mixed liquor was collected on regular basis from the experimental systems and selected samples were analyzed for 16 S r RNA genes through Illumina sequencing. Based upon the analysis of sequencing data, the taxonomical study illustrated that Proteobacteria and its sub-groups were dominating microorganisms in the treatment systems.Moreover, the analysis on microbial diversity reported that there was no significant difference(P>0.05) in microbial diversity, evenness and richness among different tanks of system 1 respectively. Adonis, ANOSIM and MRPP tests also illustrated that there was no significant difference(P>0.05) among the microbial community structures in different tanks of system 1, while cluster analysis reported that microbial communities in adjacent tanks were closely related. Further, Mantel test results revealed that total nitrogen(TN) concentration was positively correlated with microbial community structure at high significance level(P<0.05).Moving window analysis reported that microbial change rates(0.83%-7.72%) in membrane tank(E) of system 2 were relatively low than microbial change rates(0.85%-15.63%) in membrane tank(D) of system 1 because the increase in hydraulic loading rate(from 222L/m3.d to 267L/m3.d) for system 2 was lesser than the increase in hydraulic loading rate(from 222L/m3.d to 356L/m3.d) for system 1. It might suggest that the greater the change in hydraulic loading rate, the higher the elevation in microbial change rate.Taxa-time relationship(TTR) analysis illustrated that the communities in both membrane tanks followed power law relationship with the temporal turnover rate of microbial taxa of 0.13(R2= 0.99) for membrane tank(D) of system 1 and 0.20(R2= 0.99) for membrane tank(E) of system 2.