厌氧氨氧化污泥包埋固定化及其脱氮效能

Nitrogen Removal Performance of Immobilized Anammox Sludge

为维持水中厌氧氨氧化菌生物量,采用水性聚氨酯(WPU)对厌氧氨氧化污泥进行包埋固定化,同时对比聚乙烯醇(PVA)、海藻酸钠(SA)以及PVA-SA包埋后颗粒的机械稳定性和厌氧氨氧化性能.结果显示:4种包埋颗粒均表现出良好的厌氧氨氧化性能,WPU颗粒生物活性最好,机械稳定性最高,相比其他几种材料具有明显的优势,适合作为厌氧氨氧化包埋材料.在WPU包埋颗粒的连续流实验中,通过不断降低水力停留时间(HRT)的方式增加容积负荷,当容积负荷为1.697 kg/(m3·d)时,WPU包埋颗粒仍能达到80%总氮(TN)去除率,并且在100 d内没有观察到出水SS增加和颗粒碎裂的现象,表明WPU包埋颗粒具有很强的抗负荷冲击能力和厌氧氨氧化性能,并且在长期运行中能保持良好的污泥截留能力和稳定性.通过16S r DNA-Cloning分析发现:WPU包埋颗粒内厌氧氨氧化菌主要是Candidatus Brocadia fulgida(JX243641.1),包埋材料作为载体,起到保护厌氧氨氧化菌和提高生物量的作用,但对菌体本身和菌群结构没有影响.

In order to maintain the anammox biomass,waterborne polyurethane（ WPU） was employed as carriers to immobilize anammox sludge,as compared to polyvinyl alcohol（ PVA）,sodium alginate（ SA）and mixture of PVA-SA. The physical stability and anaerobic ammonium oxidation activity of the granules were evaluated. The results indicate that the four immobilized granules all have higher anaerobic ammonium oxidation activity. WPU is the most suitable immobilizing material among others,because WPU granules have shown the best biological activity and physical stability. In continuous flow experiments,the physical stability and anaerobic ammonium oxidation activity of the granules were further investigated through increasing volume loading by lowering hydraulic retention time（ HRT）. It was found that for WPU immobilized granules,there were no increasing effluent SS and granule fracture in the 100-day operation,and the total nitrogen（ TN） removal rate still reached 80% when volume loading was1. 697 kg /（ m^3·d）. Meanwhile WPU immobilized granules showed strong capability of retaining sludgeand good stability in long-term-run. Through 16 S r DNA cloning,it was discovered that the primary ANAMMOX bacteria inside the WPU-immobilized granules were affiliated to Candidatus Brocadia fulgida（ JX243641. 1）. As carriers,WPU protected ANAMMOX bacteria and increased biomass. However,they had no effect on bacteria and bacterial community structure.