فهرست نشریات علمی دسترسی آزاد ایران

Water pollution caused by synthetic dyes continues to attract serious attention from environmental researchers, particularly because many of these compounds are toxic, non-biodegradable, and remain in aquatic systems for long periods of time. This study developed a nanocomposite hydrogel utilising graphene oxide and a copolymer of acrylic acid and maleic anhydride, designated as GO/P(AA-MA), through free radical polymerisation. Its efficacy as an adsorbent for Fuchsin Basic (FB), a cationic dye commonly used in the textile industry and biological staining, was assessed. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and field-emission scanning electron microscopy (FESEM) were used to study the synthesised material. These tests showed that GO was successfully added to the polymer matrix and that the material had a rough, porous shape that was good for dye uptake. Batch experiments were conducted to investigate the influence of contact time, initial dye concentration, adsorbent mass, pH, ionic strength, and temperature on the adsorption behaviour. Kinetic data fitted the pseudo-second-order model very well (R² > 0.99), while equilibrium data were best described by the Langmuir isotherm, giving a maximum monolayer capacity of about 285 mg g⁻¹ at 298 K. Thermodynamic analysis indicated that the process is spontaneous, endothermic, and entropy-driven. The adsorbent was further tested over five adsorption–desorption cycles with only a modest loss of efficiency, which suggests that GO/P(AA-MA) is a promising and reusable material for the treatment of dye-contaminated water.