基于天然椰丝纤维填料的低氨氮废水SNAP系统自然挂膜构建

针对低氨氮废水单级自养脱氮工艺(SNAP)系统的构建需要接种特殊种源且工程应用复杂的问题，采用生物亲和性好的天然椰丝纤维为填料，开展了低氨氮废水SNAP系统自然挂膜构建实验，考察了进水COD/TN对系统脱氮效能及脱氮路径的影响。结果表明：在温度为(30±1) ℃、进水氮负荷为0.1 kg·(m3·d)−1时，采用自然挂膜以及进水${rm{NH}}_4^{+} $-N质量浓度梯度递减(由(100±3) mg·L−1降至(50±2) mg·L−1)的运行方式，经过85 d的运行，初步构建出低氨氮废水SNAP系统；该系统${rm{NH}}_4^{+} $-N和TN去除率分别为94.58%和70.07%；系统脱氮功能菌属主要有Nitrosomonas、Candidatus Brocadia。此外，进水COD/TN对系统脱氮效能及脱氮路径影响显著。当进水COD/TN分别为0、0.2、0.5、1、2时，系统TN平均去除率分别为70.07%、72.09%、75.18%、82.19%、62.19%；对于低氨氮废水，当COD/TN≤0.2时，系统主要脱氮路径为厌氧氨氧化；当COD/TN为0.5~1.5时，系统脱氮路径以短程硝化反硝化为主，厌氧氨氧化为辅；当COD/TN≥2 时，系统通过短程硝化反硝化、厌氧氨氧化路径脱氮能力进一步降低。

Construction of natural film formation in SNAP system of low ammonia nitrogen wastewater based on natural coconut fiber filler

In view of the problems of the construction of single-stage nitrogen removal system of low ammonia nitrogen wastewater using the anammox and partial nitritation that required the inoculation of special microbial sources and complex engineering applications, the study on the construction method of SNAP system based on natural film formation was carried out using natural coconut fiber filler with good biocompatibility as filler, and the influence of influent COD/TN on the denitrification efficiency and path of the system was investigated. The results showed that under the conditions of temperature (30±1) ℃ and influent nitrogen load of 0.1 kg·(m3·d)−1, operation mode with the natural film formation and the gradient decreasing concentration of influent NH4+-N (from (100±3) mg·L−1 to(50±2) mg·L−1), the SNAP system treating low ammonia nitrogen wastewater was preliminary constructed after 85 days. The removal rates of NH4+-N and TN were 94.58% and 70.07%, respectively. The main denitrification function bacteria of the system were Nitrosomonas and Candidatus Brocadia. Influent COD/TN had a significant impact on the denitrification efficiency and path of the system. The average TN removal rates at COD/TN of 0, 0.2, 0.5, 1, 2 were 70.07%、72.09%、75.18%、82.19%、62.19%, respectively. For low ammonia nitrogen wastewater, at COD/TN≤0.2, the main denitrification path of the system was anammox; at COD/TN was 0.5~1.5, the main denitrification path of the system was short-cut nitrification and denitrification, and anammox was the auxiliary; at COD/TN≥2, the denitrification capacity of the system through short-cut nitrification and denitrification and anaerobic ammonia oxidation further decreased.