Landfill Leachate Treatment

Characteristics of Landfill Leachate treatment

Landfill Leachate is a liquid that, in the course of passing through landfill gravity flow, or from precipitation and garbage itself contains water. There are many factors that could affect the liquid composition of leachate, including physical factors, chemical factors and biological factors in the migration process, so the composition of landfill leachate varies a fairly wide range. In general, the PH value between 4～9,COD in the range of 2000~62000mg/L,BOD5 in the range of 60～45000mg/L, concentrations of heavy metals in municipal wastewater are basically the same. Landfill leachate also contains highly concentrated organic wastewater, if left untreated, directly into the environment; it will cause serious environmental pollution.

Landfill Leachate treatment Process:

Landfill leachate treatment includes physical treatment and biological treatment. The physical and chemical treatment include activated carbon adsorption, chemical precipitation, density separation, chemical oxidation, chemical reduction, ion exchange, membrane dialysis, wet air oxidation, etc. At the condition COD range of 2000～4000mg/L, its changes of water quality and quantity. Outlet quality is relatively stable, especially BOD5/COD ratio is low (0.07 to 0.20). However, physical-chemical treatment requires a high cost, is not suitable for large amount of landfill leachate treatment. So it normally uses biological treatment. Biological treatment includes aerobic biological treatment, anaerobic biological treatment and a combination of both aerobic and anaerobic. Aerobic treatment includes activated sludge, oxidation aeration, aerobic stabilization ponds, trickling filters and rotating biological contactors etc. Anaerobic treatment includes upward flow sludge bed, immobilized anaerobic bioreactor, mixing reactor and an anaerobic stabilization pond.