Equilibrium studies on the uptake of nitrate and phosphate ion onto low-cost adsorbent prepared via radiation-induced graft polymerization and hydrazine hydrate functionalization

Abstract

In the study, cellulosic fabric waste-based anion exchanger (‘Cell-AE’), with abundant N+(CH3)2 functional groups were prepared by graft copolymerization of acrylonitrile (AN) onto cotton fabric waste using γ radiation 60Co, followed by chemical modification with hydrazine hydrate and alkylation with dimethyl sulfate. Factors affecting the grafting process, such as radiation dose and monomer concentration, was investigated. The main adsorbent (‘Cell-AE’) and its intermediate precursors were characterized using Fourier transform infrared spectroscopy (FTIR) and scan electron microscopy (SEM). The nitrate and phosphate sorption potentials of the Cell-AE further evaluated via batch mode. Based on the results obtained, ‘Cell-AE’ showed higher adsorption affinity towards phosphate ion (19.56 mg/g), when compared to that of the nitrate ion (11.23 mg/g). Similarly, the phosphate and nitrate ion adsorption onto ‘Cell-AE’ obeys both Dubinin–Radushkevich (D-R) and Redlich-Peterson (R-P) isotherm models, respectively. The present study conclusively proffered a potential mitigation approach to cotton fabric waste management.