Abstract: Two molecularly imprinted polymers (MIP) - poly (methacrylic acid-co-TRIM) and poly (acylamide-co-TRIM)- were synthesized in different solvents for the selective recovery of isovaleric acid (template) generated during the anaerobic digestion process. The chemical and structural characterization of the synthetic adsorbent were carried out by FT-IR, thermogravimetric analysis (TGA) and porosimetry through N2 adsorption-desorption isotherms. The selective and adsorptive performances of the imprinted polymers were evaluated by kinetic, isothermal, thermodynamic, selectivity studies and by adsorbent reuse experiments. The poly (methacrylic acid-co-TRIM) synthesized with DMSO: Chloroform presented higher selectivity and adsorption capacity for isovaleric acid in the presence of six volatile fatty acids (VFA). The kinetic results were well adjusted to the pseudo-nth-order and intraparticle diffusion models, leading to k values of 10-4 and 6 x 10-5 for the best synthesis of MIP and NIP, respectively. Moreover, the Sips model best described the adsorption isotherm and generated maximum adsorption capacity of ~ 209 mg.g-1 (at 25 °C). Cycles of MIP use-desorption-reuse indicated that the selective adsorbent performed better than commercial adsorbents losing less than 3% of adsorption capacity after 3 cycles. This article is protected by copyright. All rights reserved
Author keywords: Molecularly imprinted polymers, volatile fatty acids, Selective adsorption, anaerobic digestion, biorefinery