Adsorption kinetics and thermodynamics of Fe3O4-nanoparticle-based detoxification of process inhibitors in pretreated waste potato peel hydrolysate

This study evaluates the efficiency of Fe 3 O 4 nanoparticle adsorbent based on contact time, pH, temperature, inhibitors' initial concentration and nanoadsorbent dosage in the removal of inhibitory compounds (ICs) in pretreated waste potato peel hydrolysate using batch adsorption studies. The results revealed chemisorptive interaction between the nanoadsorbent and the ICs. The adsorption of phenol and HMF closely followed the Langmuir model ( R 2 = 0.997 and 0.966, respectively). Meanwhile, acetic acid and formaldehyde adsorption followed the Freundlich model ( R 2 = 0.985 and 0.980, respectively), whereas furfural followed the Temkin model ( R 2 = 0.970). Moreover, the ΔG 0 (the thermodynamics) decreased with increasing temperature, implying that the nature of the adsorption process is spontaneous (shown by ΔS 0 ) and endothermic (indicated by ΔH 0 ), except for furfural inhibitor. Fe 3 O 4 -nano-based adsorbent demonstrates a multi-adsorption mechanism capable of both uniform and variable binding, primarily relying on strong interactions with adsorbate molecules, which is consistent with chemisorptive mechanisms. • Adsorption kinetics of nanoadsorbent inhibitor removal were successfully studied. • The isotherm data fitted the Freundlich, Langmuir and Temkin models suitably. • Monolayer and multilayer adsorption of the inhibitors onto Fe 3 O 4 NP was revealed. • Adsorption of the inhibitors onto Fe 3 O 4 NP was mostly spontaneous and endothermic. • Chemisorptive interaction between the nanoadsorbent and the inhibitors was revealed.