A laboratory study on stabilization criteria of semi-aerobic landfill
The semi-aerobic landfill has been widely used as a sustainable landfill technology. However, the stabilization indicator system and stabilization criteria of semi-aerobic landfill have not been developed yet. In this study, the stabilization indicator system and stabilization criteria of semi-aerobic landfill were studied on the basis of simulation tests and a mathematical method. The results indicated that the stabilization process of the semi-aerobic landfill could be divided into three stages: the instability stage, the relative stabilization stage and the absolute stabilization stage, and the controlling indicators in each stage were different. Moreover, according to the physical process of stabilization and asynchronous changes of the indicators, two grade-stabilization criteria systems were developed. First, using the settlement as a controlling indicator, the second grade stabilization criteria of a semi-aerobic landfill was obtained as follows: chemical oxygen demand (COD) 400 mg L— 1, NH3-N 15 mg L—1, total dissolved solid (TDS)/total volatile solid (TVS) 6%, biodegradable matter (BDM) 5%. Second, using COD as a controlling indicator, the first grade stabilization criteria was obtained as follows: settlement 30% of height of landfill, NH3-N 15 mg L—1, TVS/TDS 3%, BDM 3%. The data obtained in this study provide an indicator system to evaluate the degree of stabilization, to manage landfill and finally, to direct its reuse.