Leachate treatment using a demonstration aged refuse biofilter.

Area of Science:

• Environmental Engineering
• Waste Management
• Water Treatment Technologies

Background:

• Landfill leachate poses significant environmental challenges due to high concentrations of pollutants.
• Aged refuse (AR) from landfills represents a potential resource for developing cost-effective treatment media.

Purpose of the Study:

• To evaluate the efficacy of a two-stage bioreactor using aged refuse as media for treating landfill leachate.
• To assess the removal rates of key pollutants including COD, NH4+-N, and BOD5.

Main Methods:

• Excavation and utilization of approximately 7000 m3 of aged refuse from Shanghai Refuse Landfill.
• Construction and operation of a two-stage bioreactor (AR biofilter) for treating 100 m3 of landfill leachate.
• Monitoring of influent and effluent concentrations of COD, NH4+-N, BOD5, suspended solids, color, and Escherichia coli.

Main Results:

• High removal efficiencies achieved: >64% for COD, 96.9%-99.8% for NH4+-N, and 95.8%-99.8% for BOD5.
• Effluent quality improved significantly, with concentrations reduced to below 300-400 mg/L (COD), 2-12 mg/L (NH4+-N), and 10-20 mg/L (BOD5).
• Total nitrogen removal was moderate (49%-63%), indicating limited denitrification capacity. Effluent met standards for suspended solids, color, pH, and E. coli.

Conclusions:

• The aged refuse biofilter is a highly effective technology for the biological treatment of landfill leachate, particularly for COD, NH4+-N, and BOD5 removal.
• The demonstration project proves the feasibility of using landfill waste as a resource for environmental remediation.
• Further research may be needed to enhance the denitrification performance of the AR biofilter.