咖啡果胶水解液作为反硝化碳源的脱氮试验研究

Study on denitrification with coffee pectin hydrolysate as carbon source

以咖啡果胶水解液作为外加碳源,通过分析不同HRT和m(COD)/m(TN)(记作C/N)下反硝化生物滤池(DNBF)的脱氮效果和反应器中微生物的群落特征,探究了咖啡果胶水解液的脱氮性能,并将其与传统碳源乙酸钠进行比较。研究结果表明,咖啡果胶水解液系统的最佳HRT=1 h,最佳C/N为6,在此条件下,当进水TN、NH4+-N分别为(33.97±2.06)、(3.09±0.19)mg/L时,咖啡果胶水解液系统可将出水TN和NH4+-N分别降至(3.12±0.59)mg/L和(2.19±0.14)mg/L,出水NO3--N稳定在1 mg/L以下,NO3--N去除率达到97.13%,NO_(2)--N无明显累积,单位质量COD反硝化去除的NO3--N为0.22 g/g,接近于对照组乙酸钠的反硝化能力。咖啡果胶水解液系统中的微生物多样性优于乙酸钠体系,Zoogloea、Ignavibacterium、unclassified_Prolixibacteraceae、Longilinea等降解有机物的功能微生物和反硝化功能微生物大量存在,保证了咖啡果胶水解液作为碳源的反硝化效果。

Coffee pectin hydrolysate as an additional carbon source,the denitrification performance was explored by analyzing the denitrification effect in denitrifying biofilter(DNBF)reactor under different HRT and m(COD)/m(TN)(C/N)and microbial community characteristics,and compared with the traditional carbon source of sodium acetate.The results showed that the optimal HRT for the coffee pectin hydrolysate system was 1 h,and the optimal C/N was 6.Under these conditions,when the influent TN and NH4+-N were(33.97±2.06)mg/L and(3.09±0.19)mg/L respec-tively,coffee pectin hydrolysate as carbon source could reduce the effluent TN and NH4+-N to(3.12±0.59)mg/L and(2.19±0.14)mg/L,respectively.The effluent NO3--N was stabilized below 1 mg/L,and the removal rate reached 97.13%.NO_(2)--N had no obvious accumulation.The NO3--N removed by denitrification per unit COD was 0.22 g/g,which was close to that of the control group sodium acetate.The microbial diversity in the system of coffee pectin hy-drolysate was better than that of sodium acetate.There were a large quantities of microorganisms with organic degra-dation function and denitrification function,such as Zoogloea,Ignavibacterium,unclassified_prolixibacitraceae and Longilinea,which ensured the denitrification effect of coffee pectin hydrolysate as a carbon source.