Utilizing gamma radiation to induce polymerization of acrylonitrile/methacrylic acid on nonwoven fibers and its potential use in metal recovery

Abstract

In this research, the focus was on creating new polymeric adsorbents through radiation-induced synthesis to effectively eliminate zinc from aqueous solutions in batch processes. The study explored the radiation-induced grafting method, a novel approach for producing polymer adsorbents, due to its advantages of process control and the absence of initiators. During the simultaneous irradiation process, acrylonitrile, methacrylic acid monomers, and phosphoric acid were grafted onto polypropylene nonwoven fiber as functional groups. To enhance zinc adsorption, the grafted polymers were modified with different amines, including diethylamine, triethylamine, ethanolamine, tributylamine, and tripropylamine. Among these, the modification with diethylamine exhibited the most promising results for zinc adsorption. After characterizing the adsorbent structure through SEM, FTIR, and TG analysis, the impact of various factors such as pH, contact time, adsorbent mass, and solution concentration on the adsorption process was investigated. Notably, under acidic conditions (pH=3) and an initial concentration of 40 ppm, a remarkable adsorption rate of over 98 % was achieved. To optimize the adsorption process, the response surface method (RSM) based on the central composite design was used to determine the ideal adsorption state. The Langmuir isotherm and the pseudo-second-order model yielded the best fit (R2=0.995) for describing the adsorption process and rate.