Removal of as(V), Cr(VI) and Cr(III) heavy metal ions from environmental waters using amidoxime and quaternized hydrogels

Authors : Duygu ALPASLAN, Tuba ERŞEN DUDU

Pages : 104-114

Doi:10.51354/mjen.936970

View : 16 | Download : 9

Publication Date : 2021-12-06

Article Type : Research Paper

Abstract :Acrylonitrile insert ignore into journalissuearticles values(AN); and 1-vinyl imidazole insert ignore into journalissuearticles values(VI); based hydrogel was prepared in bulk insert ignore into journalissuearticles values(macro); dimensions via redox polymerization technique. Afterward, this hydrogel was quaternized insert ignore into journalissuearticles values(positively charged); and exposed to the amidoximation reaction. The prepared hydrogels insert ignore into journalissuearticles values(quart-pinsert ignore into journalissuearticles values(AN-co-VI);, amid-pinsert ignore into journalissuearticles values(AN-co-VI); and pinsert ignore into journalissuearticles values(VI);); characterized using fourier transform infrared spectroscopy insert ignore into journalissuearticles values(FT-IR); and thermal gravimetric analysis insert ignore into journalissuearticles values(TGA);. Swelling experiments were performed gravimetrically at room temperature in deionized water and different pH solution. Water absorbencies of both amidoximated hydrogels and quaternized hydrogels were founded to be high. Prepared hydrogels were used to remove heavy metal ions such as arsenicinsert ignore into journalissuearticles values(V); insert ignore into journalissuearticles values(Asinsert ignore into journalissuearticles values(V););, Chromiuminsert ignore into journalissuearticles values(VI); insert ignore into journalissuearticles values(Crinsert ignore into journalissuearticles values(VI);); and Chromiuminsert ignore into journalissuearticles values(III); insert ignore into journalissuearticles values(Crinsert ignore into journalissuearticles values(III);); from aqueous media. The sorption of Asinsert ignore into journalissuearticles values(V);, Crinsert ignore into journalissuearticles values(VI); and Crinsert ignore into journalissuearticles values(III); metal ions by hydrogels were carried out at different initial metal ion concentrations, different pHs, different times in batch sorption experiments at 25oC. The maximum metal ion sorption capacity by all hydrogels was in the order: Asinsert ignore into journalissuearticles values(VI);>Crinsert ignore into journalissuearticles values(VI);>Crinsert ignore into journalissuearticles values(III);. The maximum sorption capacity for Asinsert ignore into journalissuearticles values(VI);, Crinsert ignore into journalissuearticles values(VI); and Crinsert ignore into journalissuearticles values(III); ions was found to be 598, 303.8 and 4.9 mg g-1 for amid-pinsert ignore into journalissuearticles values(AN-co-VI);, respectively. As result of, amidoximated hydrogels have more sorption capacity to metal ions than quaternized hydrogels. Three different kinetic models insert ignore into journalissuearticles values(pseudo first order, pseudo second order and intraparticle diffusion model); were also used to investigate the sorption mechanisms. Furthermore, the Langmuir and Freundlich sorption isotherms were investigated for these metal ions. As a result of, amidoximation and quaternization of AN and VI based hydrogels have been a promising technique to increase the sorption rate and capacity of hydrogels and are thought to provide great advantages in the removal of metal ions from wastewaters. Especially, among the pinsert ignore into journalissuearticles values(AN-co-VI); modification processes, amidoximation reaction was found to give better results than quaternization reaction. Prepared hydrogels were found to be more selective than Crinsert ignore into journalissuearticles values(III); versus Asinsert ignore into journalissuearticles values(V); and Crinsert ignore into journalissuearticles values(VI);.
Keywords : hydrogel, sorption, kinetics, amidoximation, quaternization