SUMMARY: Optimum landfill operation (f.e. bioreactor landfill) with leachate and gas
collection and treatment is the basis for a safe landfill with minimized emissions. Leachate
treatment is essential to reduce mainly the organic and nitrogen content in the leachate.
Biological processes are widely used as f.e. activated sludge plants and aerated lagoons. But the
remaining values of COD and AOX are still relatively high. This was the reason to develop
physical-chemical treatment steps as alternative or additional treatment methods. Many
experiences with these treatment methods have been made in the past so that leachate treatment
is state of the art. Although a great number of leachate treatment plants are under operation,
there is not only one general solution. The kind of leachate treatment chosen should be based on
the specific situation respecting the relevant regulations and costs.