Statistical optimization of process parameters for landfill leachate treatment using electro-Fenton technique

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Advanced Oxidation Processes

Background:

• Mature landfill leachate presents challenges due to its non-biodegradable nature and high organic content.
• Effective treatment of recalcitrant organics in landfill leachate is crucial for environmental protection.

Purpose of the Study:

• To optimize operating parameters for the electro-Fenton (E-Fenton) process in treating semi-aerobic landfill leachate.
• To model and evaluate the removal of recalcitrant organics using response surface methodology (RSM).

Main Methods:

• Utilized response surface methodology (RSM) to optimize electro-Fenton parameters: H(2)O(2)/Fe(2+) molar ratio, current density, pH, and reaction time.
• Developed significant quadratic polynomial models to describe COD and color removal efficiencies.
• Employed numerical optimization based on desirability functions for parameter optimization.

Main Results:

• Achieved high removal efficiencies: 94.07% for chemical oxygen demand (COD) and 95.83% for color.
• Optimized conditions included a 43-minute reaction time, pH 3, H(2)O(2)/Fe(2+) molar ratio of 1, and a current density of 49 mA/cm(2).
• Validated models demonstrated excellent fit with R(2) values of 0.9972 for COD and 0.9984 for color removal.

Conclusions:

• The electro-Fenton (E-Fenton) process is a highly effective technology for treating semi-aerobic landfill leachate.
• Optimized E-Fenton parameters significantly enhance the removal of refractory organics and color.
• RSM provides a robust framework for optimizing advanced oxidation processes for complex wastewater treatment.