Development of a Biopolymer‐Based Adsorbent From Natural Gums for Efficient Removal of Methylene Blue

ABSTRACT This study reports the sustainable synthesis of a biodegradable hydrogel designed for efficient removal of methylene blue dye from water. Natural polymers, sodium alginate, hydroxyethyl cellulose (HEC), and Acacia AR gum were employed as the hydrogel matrix, while environmentally benign crosslinkers, citric acid, and calcium chloride, were used to develop nontoxic, eco‐friendly hydrogel networks. The primary objective was to fabricate an adsorbent material that combines high dye removal efficiency with environmental safety. Among the prepared formulations, the S7‐H3CL hydrogel exhibited the highest swelling capacity (3960.6%). Fourier transform infrared (FTIR) analysis confirmed successful crosslinking within the polymer network, while scanning electron microscopy (SEM) revealed a highly porous surface morphology that supports enhanced water uptake. X‐ray diffraction (XRD) results indicated reduced crystallinity and a predominantly amorphous structure in the S7‐H3CL hydrogel, which is favorable for high swelling performance. Swelling behavior was systematically evaluated under different pH conditions, temperatures, and time intervals. The S7‐H3CL hydrogel achieved maximum swelling of 3960.6% in distilled water after 5 h, 1840% under alkaline conditions, and maintained high swelling (∼3960%) even at low temperature (3°C). UV–vis spectrophotometric analysis demonstrated effective dye adsorption, with the S7‐H3CL sample showing the lowest residual methylene blue absorbance (2.265). Biodegradation studies further confirmed the environmental compatibility and structural stability of the developed hydrogel. Overall, the results demonstrate that the prepared biodegradable hydrogel is a promising and sustainable candidate for water purification applications. Overall, this research highlights a promising, biodegradable, and nontoxic hydrogel composite for effective dye removal from wastewater, contributing to sustainable water purification technologies.