Semicarbazide Functionalized Flax Fibers for Effective Adsorption of Cr(VI) from Wastewater Samples

Semicarbazid modified flax fiber (SC.MFF) was successfully synthesized for the removal of Cr(IV) from different wastewater samples. Preparation of the SC.MFF material occurred in two main steps, the first step is the oxidation of the flax fibers by potassium periodate and the next step is refluxing of the oxidized fibers with semicarbazide ligand. The results show that quaternary ammonium cations were grafted on the surface of SC.MFF successfully. Additionally, a series of characterization of the SC.MFF sorbent was carried out using scanning electron microscopy, FTIR, elemental analysis, and X-ray diffraction spectroscopy. The effects of pH and ionic strength on the adsorption capacity were also investigated, which showed the adsorption capacity of the adsorbent decreased significantly with the increase of ionic strength and pH. Under optimized extraction conditions, the sorption capacity of Cr(VI) is 97.4 mg. g^-1. The kinetic studies show that the experimental data matches well with the pseudo-second-order kinetic model. Furthermore, the studied Cr(VI) adsorbed on the sorbent according to the Langmuir adsorption model. Finally, the SC.MFF sorbent was successfully applied for the selective and high-efficiency recovery of Cr(VI) ions from different water samples.