Hybrid process, electrocoagulation-biofiltration for landfill leachate treatment

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Wastewater Management

Background:

• Landfill leachates contain complex organic, inorganic, and microbial pollutants, necessitating advanced treatment methods.
• Single treatment processes are often insufficient for effectively treating landfill leachate to meet discharge standards.
• A combined treatment approach is generally required for efficient leachate management.

Purpose of the Study:

• To evaluate the efficacy of a sequential electrocoagulation (EC) and biofiltration (BF) process for treating landfill leachate.
• To assess the removal of specific pollutants, including total chemical oxygen demand (COD), insoluble COD, humic acids, turbidity, true color, zinc, phosphorus, and ammonia.
• To determine the potential of the hybrid EC/BF process for treating refractory wastewaters.

Main Methods:

• Sequential application of electrocoagulation (EC) followed by biofiltration (BF) to landfill leachate.
• Characterization of leachate composition and measurement of pollutant removal efficiencies.
• Fractionation of organic compounds to assess EC's effectiveness on different organic fractions.

Main Results:

• Electrocoagulation (EC) removed 37% of total COD, primarily targeting insoluble COD and humic acids.
• EC significantly reduced turbidity (82%), true color (60%), zinc (95%), and phosphorus (82%).
• Subsequent biofiltration (BF) achieved complete ammonia removal (>99%) and 42% removal of dissolved COD.

Conclusions:

• The sequential EC/BF process is effective in removing a wide range of pollutants from landfill leachate.
• This hybrid treatment approach demonstrates potential for treating various refractory wastewaters, including industrial and municipal effluents.
• The combination of EC and BF offers a robust solution for stringent leachate discharge standards.