Simulation of hexavalent chromium removal by electrocoagulation using iron anode in flow-through reactor

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Electrochemistry

Background:

• Hexavalent chromium (Cr(VI)) poses significant environmental and health risks.
• Effective removal of Cr(VI) from industrial wastewater is crucial.
• Electrocoagulation (EC) offers a promising approach for heavy metal remediation.

Purpose of the Study:

• To develop and validate a comprehensive electrocoagulation (EC) model for hexavalent chromium (Cr(VI)) reduction and precipitation.
• To investigate the influence of key operational parameters on Cr(VI) removal efficiency.
• To provide design parameters for a flow-through EC system for Cr(VI) remediation.

Main Methods:

• Development of a coupled reaction and transport model using MATLAB and PHREEQC.
• Simulation of batch electrocoagulation processes considering complexation, precipitation, acid/base, and redox reactions.
• Verification of the model against experimental data from Sarahney et al. (2012).

Main Results:

• The model accurately predicts Cr(VI) removal efficiency under varying initial concentrations, pH, current densities, and ionic strengths.
• Optimal current density range identified as 0.05-0.3 mA/cm².
• Design and operational parameters for a flow-through EC reactor were established for Cr(VI) concentrations of 10-50 mg/L.

Conclusions:

• The developed EC model provides a robust tool for simulating and optimizing hexavalent chromium removal.
• Electrocoagulation with iron electrodes is an effective method for treating Cr(VI) contaminated water.
• The study offers practical design insights for implementing EC technology in industrial wastewater treatment.