Treatment of Landfill Leachate by Anaerobic Filter: Part I: Laboratory Studies

Abstract

Abstract Widespread use of sanitary landfills for the disposal of solid waste and recognition of the serious pollution potential of leachate emanating from these landfills have forced municipalities to consider the treatment and safe disposal of this liquid waste. Limited studies conducted at relatively high temperatures (25-35°C) have established that the anaerobic filter process is more economical and effective for the treatment of leachate than other biological systems. However, there seems to be no information on the efficiency of anaerobic filters at lower temperature for the treatment of leachate. Laboratory studies were carried out over a period of 6 months to evaluate the anaerobic filter process for the treatment of leachate (COD 2,000 mg/L, BOD/COD ratio 0.5) at low temperature (10 and 25°C) . Studies on the digestion of leachate were conducted in two separate units (vol. 6.0 L) at 10 and 25°C. The hydraulic detention times were 6, 12, 24, 48 and 72 hr. Results indicated that partially stabilized leachate (i.e. from old landfills) can be treated anaerobically at low temperatures (10°C). Up to 90% of the influent COD was removed at 10°C with a 72-hr detention time and at 25°C with a 12-hr detention time. The average total gas production was 400 and 425 L/kg COD destroyed at 10 and 25°C, respectively.