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

## TL;DR

Researchers developed new adsorbent materials to selectively remove contaminants from fermented cocoa pod husk broth, improving the purity of valuable sugar alcohols like arabitol and xylitol.

## Contribution

The study introduces new adsorbent materials and evaluates their effectiveness in purifying polyol-rich fermented broths through multicomponent adsorption.

## Key findings

- Acid-activated carbon and HPA512L resin showed superior performance in clarifying the broth while preserving polyol content.
- Adsorption equilibrium data fit Extended and Modified Langmuir isotherms, indicating competitive adsorption between polyols.
- Acid-activated carbon had the highest adsorption capacities, while HPA512L resin performed better at higher temperatures.

## Abstract

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 (R
2 = 0.93–1.00), indicating chemisorption. Adsorption
equilibrium data were best described by Extended and Modified Langmuir
isotherms (R
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.