Characterization and performance analysis of leather trimming waste incorporated graphene-based composite (UPR-GO-LTW) for the removal of dye from aquatic media: A waste valorization approach

This research tackles the environmental issue of dye pollution in aquatic media, which is a significant concern due to the toxic and persistent nature of synthetic dyes. In this research, a novel composite such as, unsaturated polyester resin-graphene oxide-leather trimming waste (UPR-GO-LTW) was developed by incorporating leather trimming waste (LTW) into a graphene based polymer matrix. This composite offers an effective, sustainable, and low-cost solution for removing harmful dyes from wastewater and becomes vital to align with the sustainable development goals (SDGs) and mitigate the adverse environmental and social impacts. The integration of LTW valorizes industrial waste and enhances the adsorption properties of the composite. Different analytical techniques were employed to reveal the structural, morphological, and chemical attributes of the composite. The ability of developed adsorbent was studied under various parameters viz. pH, dose, contact time, concentration and temperature to remove C.I. acid violet 54 (AV54) dye from synthetic solution. The composite was characterized by FTIR, XRD, EDX, and FESEM to confirm its effective synthesis. The XRD results revealed that developed composite was amorphous. The optimum pH, dose, contact time, and temperature for maximum dye removal were of 3.0, 1.0 g/L, 120 min, and 318 K, respectively. The isotherm, kinetics and thermodynamics were studied to find the adsorption mechanism. The experimental coefficient value, R 2 = 0.993 of Freundlich isotherm indicating heterogeneous adsorption. The maximum capacity of UPR-GO-LTW composite was 67.11 mg/g at its optimum pH 3.0. The study also revealed that AV54 dye adsorption was endothermic, physical, spontaneous, and practicable at higher temperature as the value of enthalpy (ΔH), entropy (ΔS) and Gibbs free energy (ΔG) were 54.47, 1.90 and (-2.0449 to −7.3350) kJ/mol, respectively. The study concluded that a plenty of devoid leather trimming waste can be effectively consumed for production of valuable composite that has huge potential to remove dye from leather dyeing effluents to mitigate water pollution besides reduction of solid waste accumulation. • Characterization and use of synthesised unsaturated polyester resin-graphene oxide-leather trimming waste (UPR-GO-LTW). • The dye removal parameters, i.e. dose 1.0 g/L, contact period 120 min, pH 3.0, and temperature 318 K were optimised. • Maximum adsorption capacity was 67.11 mg/g for AV 54 dye from aqueous solution.