生物循环流化床工艺自养反硝化研究

Study on Process of Autotrophic Denitrification in Biological Circulating Fluidized Bed

对城市污水厂排水进行深度处理时,生物循环流化床提供的兼性环境有利于好氧硝化细菌和兼性厌氧自养反硝化细菌的生长,自养反硝化细菌可以在低有机碳源的情况下,以硫为电子供体进行自养反硝化从而去除NO3--N.试验以硫作为反硝化的电子供体引入自主研发的生物循环流化床中进行脱氮,试验进水各项指标参照北京市水污染物排放标准(DB11 307-2005)二级限值.在6个不同的工况下运行,工况5出水水质可达到国家再生利用景观环境用水的水质,出水ρ(NO3--N)为9.23 mg/L,去除率为70.61%;出水ρ(NH4+-N)为2.36 mg/L,去除率为77.54%;出水ρ(TN)为13.53 mg/L,去除率为68.91%;出水ρ(SO42-)为245.15 mg/L,去除的NO3--N与生成的SO42-质量比为1∶7.7.

While conducting advanced treatment of the discharge from municipal wastewater treatment plant （MWWTP）, the biological circulating fluidized bed （BCFB） can provide facultative environment for aerobic nitrifying bacteria and facultative anaerobic autotrophic denitrifying bacteria. Autotrophic denitrifying bacteria can keep significant nitrate removal under low concentration of organic carbon in the wastewater. In the experiment, sulfur took as a donor to realize autotrophic denitrification in BCFB. The influent was a simulation of discharge from MWWTP in Beijing with the concentration of Class Ⅱ standard. The reactor was operated in six different modes. In Mode 5, the effluent removal rates of NO3 ^--N, NH4^＋ -N and TN were 70.61% , 77.54-% and 68.91% respectively. The diluent concentration of NO3^ - -N, NH4^ ＋ -N and TN were 9.23, 2.36 and 13.53 mg/L, respectively. Its qualities achieved the national water quality standards for scenic environment use. The mass ratio of nitrate removal to sulfate produce was 1：7.7.