LAUSR

The present study concerns the removal of ibuprofen (IBP) from aqueous medium using glycine grafted plasma-modified cocoa shell as an effective and promising sorbent. The plasma pretreatment prior to the grafting process creates hydroxyl (–OH), carbonyl (–CO) and carboxyl (–COOH) groups, which were used as binder sites for glycine graft immobilization. The grafting technique was successful as an IR spectra of grafted biosorbent exhibited specific functional groups (N–H, C–N, –OH, C=O, COOH), which were characteristics of newly formed atomic bonds. The attachment to biomass was made through a single glycine and a glycine dipeptide esterified. The results of the removal tests demonstrated that the amounts of IBP uptake at equilibrium were higher with glycine grafted biomass (BG) than un-grafted, so going from 15.24 to 19.88 mg/g for initial 20 mg/L IBP and from 23.18 to 26.98 mg/g for 30 mg/L IBP. Amongst the tested kinetics model to predict adsorption behavior of the experimental results, the Avrami fractional-order model was the most suitable. The values of ΔH° and ΔG° suggested a spontaneous and exothermic process, which is typical for physical interaction in accordance with the Liu best-fitted isotherm model.