Irwan Kurnia, Sausan Salma Zhafira, Tarmizi Taher, Eka Djatnika Nugraha, Diana Rakhmawaty Eddy, Irkham Irkham, Hersandy Dayu Kusuma, Nova Rachmadona, Joko Waluyo, Radhia Pradana, Rusbani Kurniawan, Surachai Karnjanakom, Yeni Wahyuni Hartati, Shinji Tokonami
This study evaluates a simple thermal air oxidation strategy to enhance commercial steam-activated carbon from coconut shells (SAC) for multifunctional environmental remediation. SAC samples oxidized at different durations showed that SAC-90 (90 min at 350 °C) achieved the highest Pb2+ adsorption capacity (87.96 mg g⁻1), nearly twice that of SAC (44.50 mg g⁻1), due to increased surface oxygen-containing functional groups and specific surface area. Adsorption isotherm analysis indicated that the Langmuir and Redlich–Peterson models best described Pb2+ uptake on SAC-90, reflecting predominantly monolayer adsorption on a heterogeneous surface. Thermodynamic parameters confirmed that Pb2+ adsorption on SAC-90 is endothermic and spontaneous. In addition, SAC-90 displayed enhanced CO₂ adsorption (1.61 mmol g⁻1) and substantially improved 222Rn uptake (0.2933 cps g⁻1) while maintaining good performance over five adsorption–desorption cycles. Overall, thermal air oxidation provides an efficient and environmentally benign route to upgrade commercial activated carbon for simultaneous treatment of aqueous Pb2+ and gaseous CO₂ and 222Rn. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2026.
Department of Chemistry, Universitas Padjadjaran, Sumedang, 45363, Indonesia; Department of Environmental Engineering, Institut Teknologi Sumatera, Lampung Selatan, 35365, Indonesia; Research Center for Safety, National Research and Innovation Agency (BRIN), Metrology, and Nuclear Quality Technology, Research Organization for Nuclear, South Tangerang, 15343, Indonesia; Department of Applied Sciences, Universitas Padjadjaran, Sumedang, 45363, Indonesia; Department of Chemical Engineering, Sebelas Maret University, Surakarta, 57126, Indonesia; Department of Chemistry, Rangsit University, Pathumthani, 1200, Thailand; Institute of Radiation Emergency Medicine, Hirosaki University, 1 Honcho, Hirosaki, 036-8564, Japan