Study On Preparation And Application Of Novel Slow-rilease Carbon Source Filter

Tail waterof municipal wastewater treatment plant contain arelatively highconcentration of nitrate,withouting effective denitrificationbeforewastewater reuse, will brings security hidden danger to urban landscape greening, roadsprinkling and lakes supply etc wastewater reuse, therefore, wastewater further denitrificationbecome the key problems of the reclaimed water Securitilyreuse. Due to the low C/N tail water, reclaimed water further denitrification often need additional carbon source, the traditional liquid carbon source exists additive quantity is not easy to control, cause secondary pollution and incomplete denitrificationproblems.in recent years, the research direction is to alternatives traditional carbon source by the preparation of solid-phase slow-release carbon that is superior performance, low price.In this study, To improving denitrification rate, effectively controlling the release rate and using lifetime of the traditional starch/polyvinyl alcohol(PVA) carbon source, by adding acetate starch, hydrophobic emulsifier(SPAN80), externalcarbon sourcepackaging internalcarbon sourceand surface borate crosslinking etc methods,prepare a novel slow release carbon source.throughreleasing carbon and denitrification test, investigatethe best ratio of material, carbon source release rules and operation features of denitrification processof the novel slow-release carbon source, and through high-throughput sequencing technology analyzed the microbial community structurein denitrification process system. Specific research results are as follows:Using external carbon source packaging internal carbon source,and supplemented a small amount(5%)emulsifier(SPAN80) and borate cross-linked etc preparation method can effectively control the carbon release rate, the carbon release rate of unit mass novel slow-release carbon source is 0.034 mg/(g·h); improveing the ratio(58.2%) of the starch in novelslow-release carbon source, helping extend carbon sourceusing cycle; Acetate starch/PVA blend system denitrification rate is higher than ordinary starch/PVA blend system more than 5 times, the internal carbon source of novel slow-release carbon source using acetate starch/PVA blend systemcan improve the quality of the overall carbon source.Adding a certain proportion of sulphur powder inexternal carbon source of novel slow-release carbon source, can prepare novel slow-release carbon source filter material with high mechanical strength and long using cycle, using the novel slow-release carbon source fill denitrification filter, and studingdenitrificationprocess to the water containing nitrate nitrogen,then achieving the ideal effect of denitrification,,nitrate nitrogen removal rate can reach 100%( a influent NO3--N concentration of 22–38mg/L);Denitrification process can realize the balance between release and use of carbon source, stable effluent COD(average 21.54 mg/L); Denitrification process System have a certain ability toadapt the fluctuation of inffluent water quantity and quality, nitrate nitrogen removal loadingcan autonomiclly response fluctuations of water quantity and quality, when the hydraulic retention time is 0.5h, the highest denitrification loadof reactoris up to 12.11 mg/L·h); The denitrification system canneutralize alkalinityproduced by denitrifyingbecause of carbon source hydrolysis acidification, effluent water p H can stay in neutral range(average 7.22); When carbon source is plenty in the denitrification system, the sulfur autotrophic denitrification is not obvious, SO42- increment of in and out water is only 0.05 mg/L.In denitrification process system of novel slow-release carbon source, main phylumisproteobacteria, Bacteroidetes and Firmicutes, the three additive proportion is more than 90% of the total of microbes; Denitrifying bacteria genera are all subordinate to proteobacteria, each species are: Dechloromonas, Zoogloea, Hydrogenophaga, Thauera, Sulfurospirillum, Pseudomonas, Sulfurimonas, the priority of denitrifying bacteria is heterotrophic denitrifyinggenera, also having little hydrogen and sulfur autotrophic denitrificationgenera(existing hydrogen autotrophic denitrification is because that hydrolysis acidification of carbon source produce the small molecular substances such as CH4, H2). The Bacteroidetes phylumand Firmicutes phylummainly do the hydrolysis acidification of slow-release carbon source.This study has noveltyin slow-release carbon source material selection, formula and preparation methods, the novel slow release carbon source filter by preparetionhave good denitrificationperformance and reasonable denitrification cost; At the same time,from the microbial level parsing the inherent law of denitrification functionof the novel slow-release carbon source filter. The results has a certain application value and guiding rolefor the improvement of sewage plant tail water further denitrification technology.