Fabrication of rice straw waste via surface grafting using vanadium/mercaptosuccinic acid redox pair as environmental remediation materials instead of synthetic resins

Graphical abstract Purpose The purpose of this paper is to convert rice straw bio-waste material into value-added products that are cost-effective, sustainable, biodegradable and durable. These products serve as alternatives to materials derived from natural resources and synthetic resins, which are used globally for wastewater treatment with high cost, nonbiodegradability and their environmental concerns. This was done by surface grafting with methacrylic acid using vanadium-mercaptosuccinic acid (MSA) as a unique redox pair in aqueous medium. Design/methodology/approach The chief factors affecting grafting include the concentrations of vanadium, MSA, MAA and nitric acid, as well as the liquor ratio and polymerization time at various temperatures. The grafting parameters were intentionally selected to optimize graft yield, graft reaction efficiency and the percentage of homopolymer while minimizing the consumption of water, energy and materials. Infrared spectroscopy, scanning electron microscopy (SEM), thermal gravimetric measurement, zeta potential and Brunauer–Emmett–Teller (BET) analysis were all used to appraise the newly synthesized poly (MAA)-rice straw graft copolymers as adsorbent. Findings The findings indicate that the grafting percentage reached 42.5% at 450°C while using 0.07 mol/L vanadium ions, 0.03 mol/L MSA and 0.05 mol/L nitric acid; with a 50% MAA concentration (based on substrate weight), a liquor ratio of 20, reaction duration of 120 min and polymerization temperature (45°C). Fourier transform infrared spectroscopy was used to confirm the structure of the resulting copolymers, whereas SEM, thermal gravimetric analysis, zeta potential and BET analysis were used to characterize the surface morphology and thermal properties. Originality/value The innovation addressed here, according to the authors’ knowledge, involves converting rice straw waste, a starting pollutant bio-waste, into value-added, cost-effective products that serve as environmental remediation materials for contaminated wastewaters. This process facilitates the removal of mercuric ions and malachite green dye from their solutions, with varying graft yields as one of the unpublished factors using this type of initiator. In addition, chemical resistance and biodegradation tests are conducted to justify commercialization in terms of product durability.