废水同步脱硫脱氮关键工艺参数及微生物群落结构的研究

A large amount of untreated wastewater which contains sulfide and nitrate caused serious environment problems. The simultaneous desulfurization coupling denitrification systems based on the anaerobic biotrickling filter reactor could remove S^2- and NO_x ^--N in wastewater according to the principle of "treating waste with waste". Among all the packing materials, the biofilm growing on the polyurethane foam had the strongest biological activity and the highest efficiency of desulfurization and denitrification. The functional bacteria in the biofilm preferred oxidizing S^2- to S⁰and then further oxidizing S⁰ to SO₄ ^2- after S^2- was removed completely.Meanwhile, the degradation rate of NO₃ ^--N was faster than that of NO₂ ^--N. The relative content of SO₄ ^2- in the product was lower with the increasing of influent S/N molar ratios. Considering the actual application, the influent S/N molar ratios should be controlled between 5/3~5/4 and the influent concentration of S^2- should be below 538 mg•L^-1. The results of microbial community analysis show that Thiobacillus genus had an overwhelming superiority in the four reactors and the relative abundance was higher than 40%. Rhodanobacter, Arenimonas and Truepera genus with relatively high abundances were closely related to anaerobic denitrification. Alpha-diversity analysis of microorganisms in the four reactors shows that the system was more effective, accompanying higher the species diversity index.