Keywords: landfill leachate, ozonation, ammonia removal, biological treatment, Fenton reactive, old landfills, leachate treatment, coagulation, flocculation, chemical oxidation, biodegradability
Sequential treatment of an old-landfill leachate
This work investigates the performance of combined techniques applied to the treatment of an old-landfill leachate, which presents high salinity, low biodegradability (BOD5/COD around 0.05) and high ammonia concentration. Three sequences of processes were employed, including coagulation/flocculation, chemical oxidation, biological treatment and ammonia stripping. The association of coagulation/flocculation with ozonation promoted an increase on landfill leachate biodegradability (BOD5/COD raised to 0.20). Ammonia stripping was an essential procedure for reducing toxic effects on the biological treatment step. The treatment sequence combining coagulation/flocculation, ammonia stripping, ozonation and biological treatment led to high global removals of COD (92%) and DOC (95%).