Leachate recirculation effects on settlement and biodegradation rates in MSW landfills

Long term biodegradation of organic materials and associated settlement in municipal solid waste landfills hinder the reclamation of a landfill site a nd its conversion to other beneficial uses. The estimation of the extent of long tan biodegradation and landfill settlements become an integral part t owards final site closure and ultimate usage. The rate and magnitude of the se settlements depend not only on the refuse decomposition but also on oper ational-management practices and factors affecting biodegradation processes within landfills particularly moisture content. Field scale experiments we re conducted to evaluate biodegradation and associated refuse settlement ra tes with increased moisture content in the form of leachate recirculation. Biodegradation rates are evaluated as a function of methane gas generation rates which in rum are correlated with measured settlement rates.