Eco-Friendly Magnetic N-doped graphene derived from orange peel for Elimination of sodium dodecyl benzenesulfonate from aqueous media

Document Type : Original Research Paper

Authors

1 a Department of Environmental Engineering, Faculty of Natural Resources and Environment, University of Birjand, Birjand, Iran b University of Sistan and Baluchestan, Iran

2 Department of Environmental Sciences, Faculty of Natural Resources and Marine Sciences, University of Tarbiat Modares, Tehran, Iran

10.22111/cnmst.2025.53384.1269

Abstract

Surfactants such as sodium dodecylbenzene sulfonate (SDBS) are extensively used in industrial and household applications, causing serious environmental concerns due to their persistence and toxicity in aquatic systems. Conventional treatment methods are often ineffective for complete SDBS removal. To address this issue, this study introduces an eco-friendly magnetic nitrogen-doped graphene (MNG) synthesized from orange peel as an efficient and sustainable adsorbent for SDBS elimination. The aim of this research is to investigate the adsorption behavior of MNG toward SDBS in batch experiments. Various characterization techniques, including vibrating sample magnetometry (VSM), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, elemental analysis, and Brunauer–Emmett–Teller (BET) surface area analysis, were used to confirm the successful synthesis of the nano adsorbent. The FTIR and Raman spectra verified the presence of nitrogen- and oxygen-containing functional groups and the graphitic structure of the material. SEM and AFM images revealed a wrinkled, layered morphology with a large surface area, while VSM results demonstrated strong magnetic properties enabling easy separation. The BET analysis indicated a high specific surface area suitable for efficient adsorption. Several parameters influencing adsorption performance, including adsorbent dosage, temperature, contact time, pH, and initial SDBS concentration, were systematically evaluated. The maximum adsorption capacity reached 556 mg/g at 45 °C and pH 3. The adsorption data fitted well with the Langmuir isotherm and pseudo-second-order kinetic models. Thermodynamic analysis confirmed a spontaneous and endothermic adsorption process.

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