Technology assessment of landfill leachate treatment by evaporation
Leachate treatment by evaporation is beginning to be applied in Europe. The technology allows around 95% removal of COD, ammonia, and metals. The success of its application to landfill leachate depends upon the pH of evaporation with ammonia escaping at high pH and organic acids escaping at low pH. Process system design options include two-step, acidic/basic evaporation, carbon dioxide degassing, and gas stripping. Combustion of landfill gas can provide a low-cost energy source for the evaporation. Although the timing of gas and leachate production can cause problems, during active methane generation methane production should be sufficient for evaporation needs. Leachate evaporation is unlikely to be the only treatment process needed, but it can be a useful option for younger, stronger leachates.