Leachates Recirculation Impact on the Stabilization of the Solid Wastes – A Review

Abstract

In most countries, controlled landfills are currently the most common disposal method for municipal solid wastes (MSWs). Despite many benefits, the generation of heavily contaminated leachate with substantial differences in both chemical composition and flow rate represents a major drawback. The realization of this has compelled authorities to adopt ever more stringent establishment of pollution control requirements. Landfill leachate is a serious problem in the treatments of municipal solid wastes using landfills methods. This leachate is usually heavily contaminated, but little attention is paid to its treatment. Optimal treatment of leachates to completely decrease the harmful environmental impacts is today's challenge. However, the complex composition of leachates makes it challenging to formulate general recommendations. Leachate variability, particularly over time and within sites, suggests that the most appropriate treatments are adaptable, universal, and simple. Landfill leachate is characterized by high biological and chemical oxygen demand and is usually composed of undesirable ingredients such as inorganic and organic pollutants. Landfill leachate varies with landfill age and content, decomposition methods, hydrological and climate conditions. Recirculation of leachate does not affect alterations in the degree of biodegradability of the waste. During landfill operations, recirculation of leachate is often applied to help stabilize landfill degradation. Leachate recirculation is widely used in practical engineering, and recirculation using vertical wells is one of the more effective methods.

Experimental investigation and multi-performance optimization of the leachate recirculation based sustainable landfills using Taguchi approach and an integrated MCDM method

“…In addition, the smaller particle size of waste influences the mechanical and hydraulic properties of the compacted waste, which can be regulated by controlling the recirculation of the collected cold leachate into the landfill. Higher surface area allows for increased bacterial decomposition activity, resulting in a rise in the internal temperature of the landfill 40 . In terms of mechanical properties, the smaller particles can interlock more effectively, creating a denser and more stable waste matrix.…”