Adsorption of Volatile Fatty Acids from Fermentation Broth Using Weakly Basic Ion Exchange Resins

Abstract

Volatile fatty acids produced during fermentation processes are valuable chemical intermediates with significant applications in biofuel production, biochemical synthesis, and sustainable industrial processing. Efficient recovery and separation of these organic acids from fermentation broth remain critical challenges due to the presence of complex aqueous mixtures and dissolved impurities. The present study investigates the adsorption of volatile fatty acids from fermentation broth using weakly basic ion exchange resins under controlled operating conditions. The research focuses on evaluating adsorption capacity, selectivity, regeneration efficiency, and process optimization for enhanced volatile fatty acid recovery. Experimental analysis was conducted to examine the influence of pH, temperature, initial acid concentration, resin dosage, contact time, and competing ions on adsorption performance and separation behavior. Results demonstrate that weakly basic ion exchange resins effectively adsorb volatile fatty acids through reversible ion exchange and electrostatic interaction mechanisms, resulting in significant recovery efficiencies and improved product purification. The study further reveals that optimized pH conditions substantially enhance resin affinity toward targeted organic acids while minimizing adsorption interference from non-acidic components present in the fermentation medium. Adsorption equilibrium and kinetic analyses indicate favorable mass transfer characteristics and stable resin performance during repeated adsorption–desorption cycles. Comparative assessment with conventional solvent extraction and membrane separation methods confirms the operational advantages of ion exchange systems, including lower chemical consumption, simplified recovery processes, and reduced environmental impact.