Selective Removal of Contaminant Compounds from Polyol-Rich Fermented Broth by Multicomponent Adsorption on New Adsorbent Materials

Cocoa pod husk (CPH), a lignocellulosic agroindustrial byproduct, offers a sustainable source for producing high-value sugar alcohols such as arabitol and xylitol through microbial fermentation. However, the fermented broth contains a complex mixture of impurities, residual sugars, and phenolic compounds that impair polyol purity and require selective removal. This study investigated six adsorbent materials with distinct physicochemical properties for their ability to selectively purify polyol-rich broth via multicomponent adsorption. Activated carbons (acidic, basic, and neutral), a synthetic resin (Sepabeads SP700), and two ion-exchange resins (Diaion HPA512L and UBK550) were evaluated. pH variation (3-9) showed negligible influence on adsorption, allowing neutral conditions (pH 7) for subsequent tests. Among the materials, acid-activated carbon and HPA512L resin demonstrated superior clarification performance while preserving the polyol content. Kinetic studies fitted the pseudo-second-order model (<i>R</i> ² = 0.93-1.00), indicating chemisorption. Adsorption equilibrium data were best described by Extended and Modified Langmuir isotherms (<i>R</i> ² > 0.991), evidencing competitive adsorption between polyols. Acid-activated carbon showed the highest adsorption capacities, while the HPA512L resin offered operational benefits at elevated temperatures. These findings provide a foundation for designing efficient and sustainable downstream processes for polyol purification from biomass hydrolysates.