Abstract:

Aiming at the water quality of complex composition and low chemical oxygen demand (COD) in rare earth tailings wastewater, the anammox immobilized fillers were used for treatment. First, the adaptation and domestication of the anammox immobilized fillers were carried out, and then the nitrogen removal performance of the anammox immobilized fillers alone and the anammox immobilized fillers coupled with denitrification immobilized fillers in the treatment of rare earth tailings wastewater were respectively explored. The results showed that, the anammox immobilized fillers had good adaptability to rare earth tailings wastewater. After the adaptation and domestication by adopting the stepped substrate and shortening hydraulic retention time (HRT) operation strategy, the total nitrogen removal load rate (NRR) of the anammox immobilized fillers could reach up to 0.99kg N/(m³·d), which was 8.39 times higher than that before adaptation and domestication. The results of high-throughput sequencing showed that the relative abundance of the anammox dominant genus (Candidatus Kuenenia) increased from 5.53% to 35.67%, which achieved effective enrichment, while the dominant genus (CandidatusBrocadia) before adaptation and domestication were not adapted to the environment and were eliminated. When the concentration of ammonia nitrogen in the raw water fluctuated, the NRR of the anammox immobilized fillers alone for treating rare earth tailings wastewater could reach up to 1.02kg N/(m³·d), the average concentration of effluent ammonia nitrogen was 3.98mg/L, the removal rate of ammonia nitrogen and nitrite nitrogen reached 94.43%, and 60% of organic carbon sources were saved. By controlling the C/N ratio to 1.5∶1, the coupling of the anammox and denitrification immobilized fillers was successfully achieved, and the activity of the anammox immobilized fillers was not significantly affected. The average concentration of total nitrogen in the effluent was 0.65mg/L, the average removal rate of total nitrogen was 95.6%, and 84% of organic carbon sources were saved theoretically.

Key words: anammox immobilized fillers, rare earth tailings wastewater, nitrogen removal performance, microflora structure

摘要：

针对稀土尾矿废水的成分复杂和低化学需氧量（chemical oxygen demand，COD）的水质条件，采用厌氧氨氧化包埋填料进行处理。首先进行了厌氧氨氧化包埋填料的适应和驯化，然后分别探究了厌氧氨氧化包埋填料单独处理稀土尾矿废水和耦合反硝化包埋填料处理稀土尾矿废水的脱氮性能。结果表明，厌氧氨氧化包埋填料对稀土尾矿废水有良好的适应性，采用阶梯式底物和缩短水力停留时间（hydraulic retention time，HRT）的运行策略进行适应和驯化后，总氮去除负荷（nitrogen removal load rate，NRR）最高可达0.99kg N/(m³·d)，较适应和驯化前提高了8.39倍。高通量测序结果表明，厌氧氨氧化优势菌属（Candidatus Kuenenia）的相对丰度从5.53%上升至35.67%，实现了有效富集，而适应和驯化前的优势菌属（Candidatus Brocadia）不适应环境被淘汰。面对原水氨氮浓度波动时，厌氧氨氧化包埋填料单独处理稀土尾矿废水的NRR最高可达1.02kg N/(m³·d)，出水氨氮的平均浓度为3.98mg/L，氨氮和亚硝酸盐氮的去除率达到94.43%，可以节省60%的有机碳源。控制C/N比为1.5∶1，成功实现了厌氧氨氧化包埋填料与反硝化包埋填料的耦合，厌氧氨氧化包埋填料的活性没有受到明显影响。出水总氮的平均浓度为0.65mg/L，总氮去除率平均为95.6%，理论上可以节省84%的有机碳源。

关键词: 厌氧氨氧化包埋填料, 稀土尾矿废水, 脱氮性能, 菌群结构