Physical-chemical leachate treatment

Leachate pollution potential in MSW landfills is largely originated by a series of organic and inorganic compounds. Further to experience gained in the field of sewage treatment and the focus on high organic pollution, the biological treatment of leachate was initially implemented in many countries. However, the effluent concentrations that remained following biological treatment, featuring a low biochemical oxygen demand(BOD) and relatively high residual chemical oxygen demand (COD), resulted in the development of a wide range of additional chemical/physical treatment steps, or even in the total replacement of biological treatment. In some cases, the need for removal of specific inorganic compounds (salts, heavy metals etc.) may require targeted chemical/physical treatment. The majority of the physicalechemical processes described are applied in combination with biological treatment or other physicalechemical processes. The same processes can be successfully applied to the treatment of leachates from industrial waste landfilling. This chapter illustrates the range of feasible physicalechemical processes suitable for application in leachate treatment. Processes are described, and design principles and calculations are illustrated. Performances of both pilot- and full-scale experiences are discussed.