Effect of Lime-Stabilized Sludge as Landfill Cover on Refuse Decomposition

Abstract

Increased quantities of wastewater-treatment sludge coupled with more stringent regulations make it important to develop alternatives for residuals management. The use of a mixture of anaerobically digested, lime-stabilized wastewater sludge (LSS) and soil as a cover material was evaluated for its effect on refuse decomposition and leachate quality. Tests were conducted in 4-L reactors filled with shredded refuse and operated to accelerate refuse stabilization. Cover mixtures evaluated in quadruplicate included pure soil, pure lime, and mixtures containing 40% and 70% LSS in soil. Methane production and leachate stabilization were enhanced in reactors containing added lime or LSS. The presence of LSS in the cover did not increase the concentrations of NH