Development of an eco-friendly and cost-effective hydrogel composite utilizing leather shaving dust for solid waste reduction, heavy metal removal, wastewater treatment, and sustainable goods production

This study reports the development of a cost-effective and eco-friendly hydrogel composite (HC) by incorporating leather shaving dust (SD), a tannery byproduct, into an acrylamide-based polymer matrix. The composite was synthesized using acrylamide as a monomer, potassium persulfate as an initiator, and N, N′-Methylenebisacrylamide as a crosslinker. Comprehensive characterization was conducted to evaluate swelling behavior, mechanical performance, heavy metal adsorption, types of interactions of heavy metals in hydrogel composite, comparison with other adsorbent, theoretical explanation of the adsorbing and mechanical reusability of hydrogel composite, kinetics of the heavy metal adsorption, biodegradability, and cost-effectiveness. The composite exhibited excellent swelling properties, with swelling ratios varying according to shaving dust content and acrylamide concentration. Mechanical testing was demonstrated enhanced tensile strength, reaching a maximum fracture stress of 17.7 kPa at 9 % SD, and compressive strength peaking at 0.082 MPa under similar conditions. Adsorption experiments revealed high uptake capacities for cadmium (52 mg g −1 , 37.5 %), chromium (17.8 mg g −1 , 9.3 %), and lead (12.7 mg g −1 , 47.3 %), with efficiency plateauing at higher metal concentrations due to saturation. The composite also demonstrated partial biodegradability, with the SD fraction degrading within weeks to months, and could be regenerated for up to 10 reuse cycles. Cost analysis estimated a production cost of approximately $0.77 per liter, which is projected to decrease significantly under mass production. Beyond wastewater remediation, the hydrogel composite showed potential for manufacturing biodegradable and water-absorbing goods such as agricultural membranes, moisture-retaining packaging, and biomedical devices. These findings establish the hydrogel composite as a scalable, sustainable material that addresses dual challenges of heavy metal pollution and industrial waste management, while offering a viable alternative to conventional plastics in alignment with circular economy principles. • Development of innovative hydrogel composites for environmental remediation. • Demonstrated superior adsorption properties for heavy metals (Cd, Cr, Pb) and dyes. • Eco-friendly and cost-effective materials for wastewater treatment. • Potential for scalable application in diverse environmental contexts. • Production of cost-effective renewable goods using this sustainable material prepared from leather wastes.