Enhancing H 2 O 2 Generation Using Activated Carbon Electrocatalyst Cathode: Experimental and Computational Insights...

Area of Science:

• Environmental Chemistry
• Electrochemistry
• Water Treatment Technologies

Background:

• Granular activated carbon (GAC) is a cost-effective electrocatalyst for water treatment.
• Electrochemical generation of reactive oxygen species (ROS), including hydrogen peroxide (H2O2) and hydroxyl radicals (•OH), is crucial for contaminant degradation.
• p-Nitrophenol (PNP) serves as a model organic pollutant in water remediation studies.

Purpose of the Study:

• To investigate the impact of current intensity and cathode mesh size on ROS generation and PNP removal using GAC.
• To evaluate the effect of reactor configuration (single vs. series) on electrochemical water treatment efficiency.
• To develop and validate a numerical model for simulating H2O2 concentration profiles and understanding process dynamics.

Main Methods:

• Experimental investigation of GAC electrocatalytic performance under varying current intensities and cathode mesh sizes (-20 + 40 mesh GAC utilized).
• Comparative analysis of single and two-reactor series configurations for PNP removal and H2O2 generation.
• Numerical simulations to model H2O2 concentration, reaction kinetics, and electrode utilization efficiency.

Main Results:

• Current intensity and cathode mesh size significantly influenced PNP removal via a factorial effect.
• The -20 + 40 mesh GAC demonstrated superior performance due to optimal porosity and surface area.
• A two-reactor series configuration increased H2O2 generation by 23% and PNP removal by 32% compared to a single reactor.
• Numerical model validation showed high accuracy (R² ~0.76-0.99) in predicting H2O2 concentrations.

Conclusions:

• Optimizing GAC cathode parameters and reactor configuration is key for efficient ROS generation and contaminant removal.
• The study provides fundamental insights for enhancing electroactive surface area and electrode efficiency in sustainable groundwater remediation.
• Effective management of current magnitude, operation duration, and bubble blockage is crucial for maximizing treatment efficacy.