Start-up of pilot-scale anaerobic bioreactor landfill

The optimum start-up of a bioreactor landfill was studied. Three pilot-scale simulated test columns(denoted as R1, R2, and R3) with recirculated leachate 1.6 m3, 0.8 m3, and 0.2 m3 per week, respectively, and a control column(denoted as R4) with recirculated pure water 0.1 m3 per week were studied to analyze the variations of qualities of inflows and outflows as well as the generation of landfill gas. A relatively higher hydraulic loading could accelerate the hydrolysis of organic components in garbage and landfill gas generation rates. The proportion of net CODCr amounts flowing out of R1-R4 by mass was 6.75:3.74:1.16:1.00, while the proportion of cumulative landfill gas generation amounts was 100:00:7.92:4.78:1.30. At the initial stage of start-up, adopting higher hydraulic loading force was not favorable to the growth of the biomembrane, while it was capable of adopting lower hydraulic loading first and increasing it step by step. A larger recirculation volume accelerates the stabilization of the landfill. After 45 weeks, the quality of outflow of R1 took on partial characteristics of 'old age' leachate, with CODCr reduced to 1870 mg/L and BOD5/CODCr reduced to 0.12. Climate condition influenced the pollution loading of recirculated leachate, and the concentration of ammonia-nitrogen of the inflows had the highest value 3475 mg/L in the dry season, the lowest value 1274 mg/L in the rainy season. Rainy season is a proper time for the start-up of bioreactor landfills.