Simulation the kinetics of fluoride removal by electrocoagulation (EC) process using aluminum electrodes

Area of Science:

• Environmental Chemistry
• Water Treatment Technologies
• Chemical Engineering

Background:

• Fluoride contamination in water poses significant health risks.
• Electrocoagulation (EC) is a promising method for removing fluoride from water.
• Understanding the reaction kinetics is crucial for optimizing EC processes.

Purpose of the Study:

• To apply a variable order kinetic (VOK) model to electrocoagulation (EC) for fluoride removal.
• To investigate the influence of initial fluoride concentration, applied current, and initial acidity on the VOK model's simulation accuracy.
• To identify conditions under which the VOK model effectively describes fluoride removal kinetics.

Main Methods:

• Utilized a variable order kinetic (VOK) model derived from the Langmuir equation.
• Conducted experiments using synthetic fluoride solutions.
• Varied initial fluoride concentration, applied current, and initial acidity to assess model performance.

Main Results:

• The VOK model successfully simulated fluoride removal in most electrocoagulation systems.
• Model accuracy decreased when the initial acidity was less than the initial fluoride concentration.
• Rapid pH changes and equivalence points in titration curves correlated with model failure at high initial acidity.

Conclusions:

• The VOK model is a viable tool for describing fluoride removal kinetics in EC, with specific limitations.
• Initial solution chemistry, particularly acidity relative to fluoride concentration, significantly impacts model predictability.
• Further refinement of kinetic models may be needed to account for complex pH dynamics during defluoridation.