混合液回流比和碳源对缺氧-好氧生物脱氮系统中NDMA总前体物去除的影响

Effect of mixed-liquor return ratio and carbon sources on NDMA precursor removal in Anoxic/Oxic biological nitrogen removal system

在缺氧-好氧(A/O)脱氮系统中调节混合液回流比和外加碳源,研究了混合液回流比和不同碳源对低碳氮比城市污水中NDMA总前体物去除效果的影响.实验结果表明提高混合液回流比可以提高A/O系统对NDMA总前体物的去除效果,其作用主要通过影响缺氧池来实现;混合液回流比为400%时,可同时较大幅度提高常规指标和NDMA总前体物的去除率.外加碳源有利于A/O系统中NDMA总前体物的去除,当葡萄糖和蛋白胨作外加碳源时,A/O系统中缺氧池对NDMA的去除起主要作用;当乙酸钠作外加碳源时,缺氧池所起的作用下降;蛋白胨的加入会使进水中NDMA总前体物浓度大幅度增加;综合常规指标和NDMA总前体物的去除效果,选择葡萄糖作外加碳源比较合适.

In the Anoxic/Oxic biological nitrogen removal system, the influences of mixed-liquor return ratio and carbon sources on the removal efficiency of total NDMA precursors in the municipal wastewater with low carbon/nitrogen ratio were investigated. The results showed that： the removal efficiency of total NDMA precursors increased with the increase of the mixed-liquor return ratio in the A/O system. The anoxic tank played a major role in removing total NDMA precursors. When the mixed-liquor return ratio was 400% , both the removal efficiencies of total NDMA precursors and the conventional parameters greatly increased. The external carbon sources could increase the removal efficiency of total NDMA precursors. When glucose or peptone was added, the anoxic tank played a major role in removing total NDMA precursors. When the sodium acetate was added, the role of the anoxic tank decreased. The addition of peptone made the concentration of total NDMA precursors increase significantly. Considering the removal efficiencies of total NDMA precursors and the conventional parameters, the glucose is preferable as the external carbon source.