Multi-functionalized Cellulosic Biomass by Plasma-Assisted Bonding of α-Amino Carboxylic Acid to Enhance the Removal of Ibuprofen in Aqueous Solution

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 Delta H degrees and Delta G degrees suggested a spontaneous and exothermic process, which is typical for physical interaction in accordance with the Liu best-fitted isotherm model.