Characteristics and Kinetic Analysis of Sorption Performance of Functionalised Biomass by Various Acidic Agents

Abstract

In this study, kiwi fruit peels were functionalized using hydrochloric acid (HCl), sulfuric acid (H2SO4) and phosphoric acid (H3PO4). The properties of the functionalized materials were determined. Fourier transform infrared spectrometer (FTIR) used to show functional groups caused by the agents. Crystalline or amorphous structure clarified by X-ray diffraction (XRD) analysis. Scanning electron microscope (SEM) revealed the changes by acidic agents on the surface of kiwi peel. The elemental composition was examined using energy-dispersive X-ray spectroscopy (EDX) analysis. The performance of kiwi peels functionalized with different acidic agents in sorption experiments were investigated. Kiwi peel functionalized with hydrochloric acid (HAFKP), kiwi peel functionalized with sulphuric acid (SAFKP), and kiwi peel functionalized with phosphoric acid (PAFKP) exhibited 94.53, 98.62, and 96.76% sorption, respectively, from 50 mL of 10 mg/L dye solution for 0.1 g after 24 h. The data obtained for the sorption of the materials were evaluated with kinetic models. Pseudo-first order, pseudo-second order, Elovich and Bangham models considered the processes as time-dependent. The processes carried out with HAFKP and PAFKP were fit the pseudo-second order kinetic model and determined to interact strongly with dye via chemical bonds. SAFKP, on the other hand, interacts physically with dye according to the pseudo-first order kinetic model.