Industrial wastewater treatment using magnesium electrocoagulation in batch and continuous mode

Area of Science:

• Environmental Science
• Chemical Engineering
• Materials Science

Background:

• Industrial wastewater poses significant environmental challenges due to diverse contaminants.
• Primary clarification is often insufficient for complete pollutant removal.
• Electrocoagulation (EC) offers a promising approach for advanced wastewater treatment.

Purpose of the Study:

• To evaluate the electrocoagulation (EC) performance of a Mg-Mg system for treating mixed industrial wastewater.
• To investigate the effects of operating parameters (pH, time, current density) on pollutant removal efficiency.
• To assess nutrient (N and P) removal and characterize sludge properties.

Main Methods:

• Batch and continuous electrocoagulation experiments using Mg-Mg electrodes.
• Optimization of operating parameters including pH, reaction time, and current density.
• Sludge characterization using SEM, EDS, Fluorescence spectroscopy, and IR spectroscopy.
• Computational Fluid Dynamics (CFD) modeling for continuous reactor analysis.

Main Results:

• Optimized batch EC achieved 63.52% COD, 96% color, and 99.32% turbidity removal.
• Continuous EC removed 46.58% COD, 95.96% color, and 87.19% turbidity.
• High nutrient removal: 97% P and 67% N (batch), 98.5% P and 83% N (continuous).
• Reduced mineral content and organic/inorganic compounds in sludge post-treatment.

Conclusions:

• The Mg-Mg electrocoagulation system is highly effective for industrial wastewater treatment, including nutrient removal.
• Optimized batch and continuous EC processes demonstrate significant pollutant reduction capabilities.
• The energy cost for batch EC is economically viable at US$0.05/m³.
• CFD modeling confirms efficient mixing and turbulence in the continuous reactor.