Irwan Kurnia, Luthfia Sofi Nur Fadlila, Hersandy Dayu Kusuma, Haryono, Nurochma Juliasih, Tarmizi Taher, Uji Pratomo, Joko Waluyo, Antonius Indarto, Yusi Deawati, Yeni Wahyuni Hartati
The rayon yarn production process generates zinc-containing waste effluent that poses significant environmental concerns. Due to stringent environmental regulations and restrictions on harmful metals and other pollutants, wastewater discharges are strictly regulated. In this study, real samples of rayon viscose effluent were investigated for zinc removal using a two-stage adsorption process with standard steam activated carbon (SAC) and thermally air-treated steam activated carbon (SAC-350). In the two-stage adsorption process, SAC-350 adsorbed 63.5% of the Zn2⁺ with a cumulative adsorption capacity of 780 mg g−1. Furthermore, kinetic study analysis confirms that Zn2⁺ adsorption on SAC-350 follows a pseudo-first-order model, indicating a physisorption process. Moreover, density functional theory (DFT) calculations confirm that carboxylic groups on carbon material play an important role in Zn2⁺ interaction, showing the lowest adsorption energies among the other evaluated functional groups. The treated rayon viscose effluent demonstrated a decrease in chemical oxygen demand (COD) that consequently enhanced the wastewater quality. This study demonstrates that thermally air-treatment can improve the adsorption capacity of activated carbon and provide an environmentally friendly method for the efficient removal of heavy metals from industrial wastewater. © 2025 Wiley-VCH GmbH.
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang, Indonesia; Study Center of Sensor and Green Chemistry, Faculty of Mathematics and Natural Science, Universitas Padjadjaran, Bandung, Indonesia; Department of Applied Sciences, School of Vocational, Universitas Padjadjaran, Sumedang, Indonesia; South Pacific Viscose Company, Purwakarta, Indonesia; Department of Environmental Engineering, Institut Teknologi Sumatera, Lampung Selatan, Indonesia; Department of Chemical Engineering, Sebelas Maret University, Surakarta, Indonesia; Department of Bioenergy Engineering and Chemurgy, Faculty of Industrial Technology, Institut Teknologi Bandung, Sumedang, Indonesia