Abstract:In order to improve the efficiency of denitrification in wastewater treatment, the denitrifying strains N1, N9 and N10, which have been screened out in the laboratory, were prepared into a composite microbial agent. The influence of different temperatures, carbon-to-nitrogen ratios (C/N), and carbon source types on the growth and denitrification characteristics of the composite microbial agent was investigated, showing significant practical value. The results showed that 92.61% nitrate nitrogen, 60.02% total nitrogen, and 58.48% chemical oxygen demand could be removed by the compound microbial agent under the conditions of 30 ℃, C/N ratio of 10, and soluble starch as the carbon source after 48 h. Moreover, the denitrification effect was substantial within the C/N ratio range of 2 to 10, indicating that the composite denitrification microbial agent could have application prospect in the denitrification process of low C/N ratio wastewater.