Diclofenac sodium adsorption on activated carbon: experimental, modeling and bayesian statistics

Area of Science:

• Environmental Science
• Chemical Engineering
• Pharmaceutical Science

Background:

• Diclofenac sodium is a common pharmaceutical pollutant.
• Activated charcoal is a widely used adsorbent for water treatment.
• Effective modeling is crucial for optimizing contaminant removal processes.

Purpose of the Study:

• To develop and validate a mass balance-based model for diclofenac sodium adsorption on activated charcoal in a fixed bed column.
• To investigate the influence of a novel solid-phase mass transfer driving force model with a gamma exponent.
• To evaluate the performance of various adsorption isotherms (Langmuir, Freundlich, Sips, Redlich-Peterson) within the model.

Main Methods:

• A mass balance-based model for a fixed bed adsorption column was developed.
• A novel solid-phase mass transfer driving force model with a gamma exponent (0 < γ ≤ 2) was proposed.
• Bayesian statistics and Markov chain Monte Carlo (MCMC) methods were employed for parameter estimation.
• The model was validated using experimental data under varying initial diclofenac sodium concentrations.

Main Results:

• The developed model successfully simulated the adsorption of diclofenac sodium.
• The proposed driving force model with the gamma exponent provided a flexible representation of mass transfer kinetics.
• Model validation confirmed its accuracy across different operating conditions.
• Comparison with established isotherms provided insights into the adsorption equilibrium.

Conclusions:

• The study presents a robust modeling framework for diclofenac sodium adsorption on activated charcoal.
• The novel mass transfer model enhances the understanding of adsorption dynamics in fixed-bed systems.
• This research contributes to the development of efficient water treatment strategies for pharmaceutical contaminants.