Adsorption of ferulic acid from an alkali-pretreated hydrolysate using a new effective adsorbent prepared by a thermal processing method

Abstract A new adsorbent (AEPA250) was prepared using the enzymatic hydrolyzed residue of rice straw in an air environment at 250 ℃ by a thermal processing method. Compared to the commercial adsorbent, AEPA250 possessed a larger specific surface area of 277.680 m2 g-1, and the maximum adsorption efficiency of ferulic acid from alkali-pretreated hydrolysate of rice straw achieved 70.33% at the optimum conditions. Adsorption kinetics and isotherm studies showed that the pseudo second-order (PSO) (0.997 ≤ R2 ≤ 0.999) and Liu models (0.931 ≤ R2 ≤ 0.997) exhibited better fitting results, which indicated that chemical and saturable adsorption existed between ferulic acid and AEPA250. An adsorption thermodynamics study revealed the spontaneous and endothermic adsorption process (ΔHo > 0 and ΔSo