Synthesis of borax cross-linked Jhingan gum hydrogel for remediation of Remazol Brilliant Blue R (RBBR) dye from water: Adsorption isotherm, kinetic, thermodynamic and biodegradation studies

This paper reports synthesis of hydrogel from an unexplored Jhingan gum via microwave assisted technique for efficient remediation of toxic RBBR dye from aqueous solution. The synthesized hydrogel was confirmed through various analytical techniques. Adsorption mechanism was studied comprehensively and correlation coefficient (R-2) values of Langmuir (0.8492-0.9147), Freundlich (0.9802-0.9932), Temkin (0.7744-0.9048), Sips (0.9832-0.9987) recommended that adsorption process fitted best with Freundlich and Sips models. Additionally, the sorption energy E, calculated using the Dubinin-Radushkevich isotherm, has a value of 0.971-0.989 kJrnol(-1), which confirmed that the type of adsorption was physisorption. Kinetic study revealed that adsorption was well described by pseudo-second-order kinetic. Feasibility of adsorption process determined thermodynamically suggested an endothermic process accompanied with decrease in randomness and non-spontaneous nature. The synthesized hydrogel exhibited an excellent regeneration capacity. The biodegradation study revealed that the hydrogel degraded 89.5% in 180 days with a half-life of 53.3 days. (C) 2020 Elsevier B.V. All rights reserved.