Micro-aeration and leachate recirculation for the acceleration of landfill stabilization: Enhanced hydrolytic acidification by facultative bacteria.

[Display omitted] • Micro-aeration and leachate recirculation accelerate the stabilization of landfill. • The integrated process promotes the enrichment of facultative bacteria. • Bacteria that cause hydrolytic acidity benefit the stabilizing process. • Synergy between methanogens and acidifying bacteria is enhanced in integrated process. The long duration of landfill stabilization is one of the challenges faced by municipalities. In this paper, a combination of micro-aeration and leachate recirculation is used to achieve rapid degradation of organic matter in landfill waste. The results showed that the content of volatile fatty acids (VFAs) in the hydrolysis phase increased significantly and could enter the methanogenic phase quickly. Until the end of the landfill, the removal rates of chemical oxygen demand (COD), total phosphorus (TP) and ammonia nitrogen (NH 4 +–N) by micro-aeration and leachate recirculation reached 80.17 %, 48.30 % and 48.56 %, respectively, and the organic matter degradation rate reached 50 %. Micro-aeration and leachate recirculation enhanced the abundance of facultative hydrolytic bacteria such as Rummeliibacillus and Bacillus and the oxygen tolerance of Methanobrevibacter and Methanoculleus. Micro-aeration and leachate recirculation improved the organic matter degradation efficiency of landfill waste by promoting the growth of functional microorganisms. [ABSTRACT FROM AUTHOR]