Abstract：
Abstract:This paper investigated the effect of nitrogen loading rates (NLRs) on stability of aerobic granular sludge (AGS) for treating simulated ionic rare earth mine wastewater with high ammonia nitrogen and extremely low organic content. Mature AGS from a sequencing batch reactor (SBR) was seeded into five identical SBRs (R1, R2, R3, R4 and R5). The five reactors were operated with different NLRs (0.2, 0.4, 0.8, 1.2 and 1.6 kg/m3·d). After 30 days of operation, R1, R2 and R5 were dominated by broken granules, while most of the granules in R3 and R4 still maintained a complete structure. The properties of granules from R1, R2, R3, R4 and R5 deteriorated to varying degrees, while the granules from R3 and R4 showed better stability than that from R1, R2 and R5. In R1, R2, R3 and R4, the steady-state ammonia nitrogen removal efficiencies were all greater than 90%, and the steady-state removal efficiencies of total inorganic nitrogen (TIN) were approximately 30%. In R5, the removal efficiencies of ammonia nitrogen and TIN were both approximately 70%. The dominant nitrifying and denitrifying bacterial genera of the granules from the five reactors were Nitrosomonas and Thauera, respectively, and their relative abundance was much higher in granules from R3 and R4. The results demonstrated that a relative equilibrium between the growth and metabolism of nitrifying/denitrifying bacteria was achieved when NLR was between 0.8 and 1.2 kg/m3·d, which could provide technical support for the stability maintenance of AGS in the treatment of ionic rare earth mine wastewater.
摘要：
摘要：研究了氮负荷率(NLRs)对好氧颗粒污泥(AGS)处理高氨氮和极低有机物含量离子稀土矿山废水稳定性的影响。将来自序批式反应器(SBR)的成熟AGS接种到五个相同的SBR(R1、R2、R3、R4和R5)中。五个反应器以不同的NLR(0.2、0.4、0.8、1.2和1.6kg/m3·d)操作。手术30天后,R1、R2和R5以破碎颗粒为主，而R3和R4中的大多数颗粒仍然保持完整的结构。R1、R2、R3、R4和R5颗粒的性能有不同程度的恶化,而来自R3和R4的颗粒显示出比来自R1、R2和R5的颗粒更好的稳定性。R1、R2、R3和R4的稳态氨氮去除率均大于90%,总无机氮(TIN)的稳态去除效率约为30%。在R5中，氨氮和TIN的去除效率均约为70％。来自五个反应器的颗粒的主要硝化和反硝化细菌属是Nitrosomonas和Thauera，分别,在R3和R4的颗粒中，它们的相对丰度要高得多。结果表明，当NLR在0.8和1.2kg/m3·d之间时，硝化/反硝化细菌的生长和代谢之间达到相对平衡。为AGS处理离子型稀土矿山废水的稳定性维护提供技术支持。
