Abstract:

A sulfur autotrophic denitrification (SADN) coupled anaerobic ammonium oxidation (ANAMMOX) autotrophic denitrification system was successfully developed by adding ANAMMOX sludge to an SADN reactor with sodium thiosulfate as electron donor. The nitrogen removal performance of the coupled system during start-up and stable operation was investigated. The coupled system achieved high efficiency and stable operation at (36±1)℃ and a total nitrogen loading rate of 0.8kg/(m³·d), with a maximum total nitrogen removal efficiency of 94.6%, which was higher than the maximum ANAMMOX theoretical total nitrogen removal efficiency of 89%. The influence of S/N (ratio of influent S₂O{}_{\mathrm{3}}^{\mathrm{2}-}-S to NO{}_{\mathrm{3}}^{-}-N) on the nitrogen removal was investigated, and the optimal operating parameters were determined. Among them, the coupled system could maintain the best nitrogen removal efficiency when the influent S/N was in the range of 1.6—2.2. The contribution of ANAMMOX and SADN pathways to nitrogen removal was stable at about 96.2% and 3.8%, respectively, and ANAMMOX dominated the coupled system. The sludge activity after long-term operation was tested by batch experiments, and the results showed that both SADN and ANAMMOX bacteria were able to maintain high activity, and the two were synergistic cooperation with complementary substrates in the coupled system.

Key words: sulfur autotrophic denitrification(SADN), anaerobic ammonium oxidation(ANAMMOX), deep nitrogen removal, S/N ratio

摘要：

通过在以硫代硫酸钠为电子供体的硫自养反硝化（SADN）反应器中加入厌氧氨氧化（ANAMMOX）污泥，成功构建了SADN耦合ANAMMOX自养脱氮系统。试验探究了耦合系统的启动与稳定运行期间的脱氮性能，在温度为(36±1)℃、进水总氮（TN）负荷为0.8kg/(m³·d)的条件下，耦合系统实现了高效稳定运行，总氮去除率最高达到94.6%，大于ANAMMOX理论最高总氮去除率89%。研究了S/N比（进水S₂O{}_{\mathrm{3}}^{\mathrm{2}-}-S与NO{}_{\mathrm{3}}^{-}-N的比值）对脱氮效果的影响，确定了最佳运行参数。其中，在进水S/N比在1.6~2.2时，耦合系统能够保持最佳的脱氮效率。ANAMMOX和SADN途径对总氮去除贡献率分别稳定在96.2%和3.8%左右，ANAMMOX在耦合体系中占据主导地位，进水总氮主要由ANAMMOX途径去除。通过批次实验测试长期运行后的污泥活性，结果表明SADN菌和ANAMMOX菌均能够保持较高的活性，两者在耦合体系中为底物互补的协同合作关系。

关键词: 硫自养反硝化, 厌氧氨氧化, 深度脱氮, S/N比