A novel in situ method to enhance mature leachate quality in Aerobic-Anaerobic Recirculation Landfill

The in-situ aeration combined with leachate recirculation technology is an effective method for treating carbon and nitrogen pollutants in landfill. This paper determined the effect of in-situ treatment of aged landfill leachate in aerobic-anaerobic recirculation simulated landfill (AARL) and the feasibility of hydroxylamine addition to promote TN removal. The results showed that the hydroxylamine treatment group had higher TN removal and SND efficiency. The high-throughput sequencing technology showed that the addition of hydroxylamine could promote the abundance of Nitrosomonas (Ammonia Oxidizing Bacteria) in the aerobic zone. However, due to the higher nitrite oxidation efficiency of nitrate oxidizing bacteria (NOB) compared with the ammonia oxidation efficiency of Ammonia Oxidizing Bacteria (AOB), there is no accumulation of nitrite. It was found that Methylocaldum was the dominant bacteria in AARL. This study would contribute to the development of AARL landfill in the in situ remediation treatment of mature landfill leachate.