CRI系统厌氧氨氧化协同反硝化脱氮的启动及性能

Start-up and Performance of Anammox and Denitrification for Synergistic Nitrogen Removal in CRI Systems

为进一步提高脱氮效率,该文采用人工快渗(CRI)系统作为厌氧氨氧化反应器,考察了有机物添加对氮素污染物转化及菌群结构的影响,探讨了厌氧氨氧化协同反硝化脱氮的可行性。结果表明,通过逐步提高进水COD浓度至20 mg/L,可在49 d内实现CRI系统厌氧氨氧化协同反硝化的快速启动,稳定运行期间TN平均去除率达到98.1%,相比未添加有机物时启动周期缩短了11 d,TN平均去除率提高了7.3%。当进水COD浓度提高至25 mg/L时,厌氧氨氧化对脱氮的贡献率降低了27.2%,主要厌氧氨氧化功能菌属Candidatus Kuenenia的相对丰度降至12.42%,而反硝化功能菌属Flavobacterium的相对丰度升至11.16%,反硝化菌与厌氧氨氧化菌竞争反应基质而导致厌氧氨氧化活性被削弱,TN平均去除率下降了13.5%。因此,将进水有机物浓度控制在适宜范围时可有效改善厌氧氨氧化的脱氮性能。

To further improve the nitrogen removal efficiency,constructed rapid infiltration(CRI)systems were adopted as the anammox reactors to investigate the effect of organic matter addition on nitrogen transformation and bacterial structure,and to explore the feasibility of anammox synergistic denitrification.The results showed that anammox synergistic denitrifi⁃cation of the CRI system could be rapidly started up within 49 days via increasing influent COD concentration gradually to 20 mg/L.The average removal efficiency of TN achieved 98.1%during stable operation,which shortened the start-up period by 11 days and increased the average removal efficiency of TN by 7.3%compared with that without adding organic matter.When the influent COD concentration increased to 25 mg/L,the contribution of anammox to nitrogen removal dropped by 27.2%,the relative abundance of the main anammox functional bacteria Candidatus Kuenenia dropped to 12.42%,while that of denitrifying functional bacteria Flavobacterium increased to 11.16%.The average removal efficiency of TN dropped by 13.5%due to the weakened anammox activity as a result of competition between denitrifying bacteria and anammox bacteria for the reaction substrate.Therefore,controlling the influent organic matter concentration in a suitable range can effectively improve the nitrogen removal performance of anammox.