Microbial Community Structure And Mechanism Of Phosphorus Removal By Gasification

Phosphorus pollution in water is becoming more and more serious.The eutrophication of water bodies seriously threatens the natural environment.The traditional sewage phosphorus removal process has a series of problems such as complicated process and secondary pollution.The process can not effectively solve the contradiction between the lack of phosphorus resources and the phosphorus pollution of water bodies.In order to realize the transformation from "phosphorus removal" to "phosphorus recovery",the microbial community structure,mechanism of action and kinetic model of phosphate reduction system based on the technology of phosphorus removal by gasification are deeply studied to provide theoretical basis for practice and promote the application in practice.The 16S rRNA sequencing technique was used to detect the microbial community structure in the initial,middle and best period of phosphine production in the system.The species composition of the three periods was analyzed.The order of species richness was:the medium period,the best period and the initial period;the order of species uniformity was:the medium period,the initial period and the best period;the order of species diversity was:the medium period,the early period and the best period.At the "gate" taxonomic level,combined with the species composition and the significant difference between the medium and the best period,it is considered that the phosphate-reducing species or the synergistic species might be Proteobacteria,Saccharibacteria,Chloroflexi,Gemmatimonadetes and Firmicutes.The species that may contain competing species are Bacteroidetes and Actinobacteria.At the"species" taxonomic level,the Venn diagram of the species relationship and the Sunburst analysis were combined to filter out the phosphate-reducing bacteria or the collaborator.The more likely target species and the highly competitive with phosphate-reducing bacteria were found to be mostly unclassified and non-human cultured.Through the classification analysis of COG function,it was found that the phosphate reduction system enhanced the eight functions from the initial stage of phosphine production to the optimal period.They are carbohydrate transport and metabolism,energy production and conversion and so on,which promoted the production of phosphine.According to the KEGG function analysis,there were 286 enzymes related to phosphorus and the phosphorus-related metabolic pathways were 5 such as Phosphatidylinositol signaling system.Combined with thermodynamic comprehensive analysis,it is speculated that the mechanism of phosphate reduction may be:the system transports glucose by PTS pathway,the phosphate and hypophosphite metabolic pathways and cell transmembrane transport provided H2PO4-,the pentose phosphate metabolic pathway provides energy and the phosphatidylinositol signaling system and phosphoinositide metabolic pathway provide a favorable intracellular environment for the production of phosphine.The regression equation was established by experiment to determine the kinetic model of organic degradation,microbial growth equation and phosphorus removal equation.lt provides theoretical basis and practical technology for the amplification experimental research of this process,and promotes its application in practical engineering.