Combined ozone-activated sludge treatment of landfill leachate

Biological treatment is widely preferred by many landfill owners to remove the bulk of the pollutants in leachate. Specific problems due to toxicity a nd nutrient deficiencies are however frequently reported. This study invest igates the possibility of pre-treating leachate to decrease its toxicity an d increase its biodegradability, using ozonation. Lab-scale and pilot testi ng has shown that nitrification toxicity was minimised by ozone pre-treatme nt. A decrease of the COD/BOD-ratio from 16 to 6 was achieved, making the p re-treated leachate co-treatable in municipal sewage treatment. The operati onal cost for the pretreatment was estimated at 1.34 Euro/kg COD.