Monitoring and long-term prediction of refuse compositions and settlement in large-scale landfill

Settlement and changes in refuse composition for total sugar, raw cellulose, biological degradable matter, volatile solid, organic carbon, were monitored in a large-scale experimental landfill unit and closed landfill units at Shanghai Refuse Landfill from April 1995 through to October 1998. Mathematical simulation formulae between these parameters and refuse age were developed based on the data obtained from the experimental landfill unit and validated by data from landfill units closed in April of 1991, 1992, 1993 and 1994. Long-term predictions for these parameters for the landfill were made using these formulae. It was predicted that the refuse might be fully mineralized and the cumulative settlement might be over 30% of the initial height after around 22 to 30 years. The stabilization process and reuse approaches for landfills based on the compositions and settlement are discussed.