Mature landfill leachate wastewater (LLW) was characterized by high ammonia, refractory chemical oxygen demand (COD) and heavy metal contents, which limits the nitrogen removal in conventional activated sludge systems. Granular sludge is known to be more resistant to toxic compounds because of its dense structure and diverse microbial community. Here, granular sludge-based reactor (GSR) was applied with nitritation/denitritation (Nit/DNit) process for effective ammonia-rich mature LLW treatment at 20 °C. After a short startup period, the efficiencies of ammonia removal and total inorganic nitrogen removal stabilized at 99 % and 93 %, respectively, under a hydraulic retention time (HRT) of 6 h. High ammonia oxidation rate (~ 0.64 g N/g VSS/d) was achieved, with ~93 % ammonia conversing to nitrite before being reduced to nitrogen gas. Microbial analysis results revealed that Nitrosomonas (ammonia oxidizing bacteria) and Thauera (denitrifiers) were the dominant bacteria with key functional genes involved in the Nit/DNit. With an increase in the LLW loading, increased ammonia oxidation rates and biomass retention were also observed. This study demonstrated that granular sludge-based technology is feasible for mature LLW treatment.

成熟的垃圾渗滤液废水 (LLW) 的特点是氨含量高、难处理化学需氧量 (COD) 和重金属含量高，这限制了常规活性污泥系统中的氮去除。众所周知，颗粒污泥因其致密的结构和多样的微生物群落而对有毒化合物具有更强的抵抗力。在这里，基于颗粒污泥的反应器 (GSR) 与亚硝化/反亚硝化 (Nit/DNit) 工艺相结合，在 20 °C 下进行有效的富氨成熟 LLW 处理。在短暂的启动期后，在 6 小时的水力停留时间 (HRT) 下，氨去除率和总无机氮去除率分别稳定在 99% 和 93%。实现了高氨氧化速率（~ 0.64 g N/g VSS/d），其中约 93% 的氨在还原为氮气之前转化为亚硝酸盐。Nitrosomonas（氨氧化细菌）和Thauera（反硝化菌）是主要的细菌，其关键功能基因涉及 Nit/DNit。随着 LLW 负载的增加，还观察到氨氧化率和生物量保留增加。该研究表明，基于颗粒污泥的技术对于成熟的 LLW 处理是可行的。