[Experimental study of autotrophic denitrification bacteria through bioaugmentation of activated sludge from municipal wastewater plant].

Activated sludge of municipal wastewater treatment plant was domesticated by sulfur as the electron donor under autotrophic. The sludge activity was determined by measuring growth rate of sludge. The removal efficiency of nitrate and sulfate production efficiency were analyzed by continuously measuring the concentration of NO3(-)-N and SO4(2-). When the removal efficiency of nitrate was more than 90%, 16S rRNA genetic libraries were built up to compare their microbial biodiversity. The growth rate of sludge is 0.177 g/(L x d). The relation between concentration of nitrate and time meets first order reaction kinetics. The bacteria in the sludge affiliated with Beta-Proteobacteria, Deta-Proteobacteria, Gamma-Proteobacteria and Unclassified bacteria. Beta-Proteobacteria is the main phylum in the sludge. Bacteria related to Thiobacillus denitrificans from denitrifying bioreactor perform 48.65%. In addition, the bacteria of Denitratisoma sp., Curvibacter sp., Thermomonas sp., Geobacter sp. are existed in the sludge. The study of autotrophic denitrifying bacteria diversity is conducive to optimization of reaction conditions and efficient removal of nitrate.