Treatment of stabilized landfill leachate by physico‐chemical and bio‐oxidation processes

Abstract

Abstract In this work the treatment of leachate originating from an old landfill was compared using a variety of methods both singularly and in combination. Aerobic biological treatment gave a COD removal ranging from 32–35%, but it was very effective for BOD and ammonia removal (97% and 99%, respectively). By using chemical oxidation a COD reduction up to 33% was achieved. The application of chemical precipitation gave a COD removal in the range of 36–42%. The combination of biological and chemical oxidation, biological oxidation and chemical precipitation or chemical oxidation and chemical precipitation, led to a COD reduction up to 57%. The best results were obtained when a biological oxidation was applied in two stages combination with chemical oxidation and chemical precipitation reducing COD concentration values up to 87%.