新型碳源用于脱氮的经济性对比及生物群落分析

Economic comparison and microbial community analysis of nitrogen removal with new carbon sources

以淄博某污水厂生化出水为原水,通过活性污泥法反硝化小试试验,重点考察了3种新型碳源(农产品副产物BC5、制糖副产物二次加工品BC6和乙酸盐复配产品BC8)和2种常规碳源(C_(6)H_(12)O_(6)、NaAc)的反硝化脱氮效果,以确定较优厂试新型碳源。小试结果表明,BC8在较优投加C/N为4.5时,可在160 min内将进水总氮由32.4降至<7 mg/L,最大反硝化速率达21.6 mg-NO_(3)^(-)/(L·h)。在88 d厂试期内,在TN约5 mg/L同等出水水质条件下,BC8日均用量和使用成本仅为葡萄糖的38.2%和92%,经济性良好。对厂试活性污泥微生物群落多样性分析表明,碳源类型对微生物优势菌门类影响不大,但有助于提高Pseudomonas、Comamonas等反硝化菌群丰度。

A laboratory denitrification test was performed for the biological treatment of the secondary biochemical effluent of a wastewater treatment plant in Zibo.Five external carbon sources,including conventional carbon sources(glucose,sodium acetate)and new carbon sources(BC5,BC6 and BC8),were investigated through batch denitrification experiments by the activated sludge process.The results of the laboratory test showed that BC8 performed best synthetically.When the carbon source changed from glucose to BC8,the influent TN could be reduced from 32.4 mg/L to<7 mg/L within 160 minutes when the C/N ratio was 4.5 and the maximum value of denitrification rate was 21.6 mg NO_(3)^(-)-N/(L·h).Furthermore,during 88 days’plant test,the average daily dose and cost of BC8 were only 38.2%and 92%of glucose.Analysis of microbial community diversity in activated sludge showed that carbon source type had little effect on the dominant microbial bacteria.However,it was helpful to increase the abundance of denitrifying bacteria such as Pseudomonas and Comamonas.