Three management options for the treatment of leachate from landfilled domestic solid waste have been evaluated. Research results show that leachate can be treated effectively in aerobic systems, with high organic carbon and ammoniacal nitrogen removals of >90% and >85% respectively. Optimum SRT of about 10 days is required. Anaerobic treatment (UASB) with HRT's of between 1.0 and 4.0 days results in COD destruction of about 85% with high methane production (400-600 mg/g COD removed) and provides an intermediate effluent suitable for polishing to a high standard.
Recirculation of leachate through the landfill by itself cannot provide a complete treatment, although significant reductions in volume and strength of leachate can be obtained.