Electrochemical treatment of landfill leachate

Abstract

A significant municipal solid waste is managed by disposition in a landfill. This kind of management system makes producing leachate with toxic characteristics unavoidable. Landfill leachate is a potential pollutant source containing several types of organic and inorganic pollutants that can induce risk toward public health and ecosystems if they are not appropriately treated. Among the parameter affecting the landfill leachate, the age of the landfill is considered to be a determinant factor controlling the leachate composition. Conventionally, the leachate has been treated by an individual or combination of biological, physical, and chemical methods. Recently, electrochemical methods have paid particular attention to the treatments of landfill leachate, presenting high efficacy for the degradation of refractory compounds. Electrochemical methods offer several advantages: small space requirement, short treatment time, low requirements of chemical reagents, and easy automation. Electrochemical methods commonly used for the treatment of landfill leachates are: electro-oxidation, electro-coagulation, and electro-Fenton. Each of these methods can be affected by different parameters. Commonly, electrochemical processes are influenced by several operating parameters such as electrode material and design, the inter-distance between electrodes, treatment time, initial pH value and conductivity of the solution, applied current density, mixing and electrolytes added. The electrochemical process can also be combined with biological and physicochemical processes as pre- treatment or post-treatment to enhance the treatment of landfill leachate.