High-energy ball milling enhances bisphenol A adsorption by increasing site accessibility and modifying adsorption energetics in powdered activated carbon
High-energy ball milling enhances bisphenol A adsorption by increasing site accessibility and modifying adsorption energetics in powdered activated carbon
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DOI: https://doi.org/10.22533/at.ed.1317632627033
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Palavras-chave: Bisfenol A; Moagem de alta energia com esferas; Carvão ativado em pó; Isotermas de adsorção; Acessibilidade do sítio de adsorção; Distribuição energética..
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Keywords: Bisphenol A; High-energy ball milling; Powdered activated carbon; Adsorption isotherms; Site accessibility; Energy distribution.
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Abstract: The environmental persistence of the plasticizer Bisphenol A (BPA) necessitates innovative and green adsorption solutions. High-energy ball milling (HEBM) has emerged as an effective, low-cost method for enhancing the adsorption performance of carbonaceous materials, particularly powdered activated carbon (PAC). In this study, two PACs were subjected to HEBM under identical conditions and evaluated for BPA adsorption in aqueous solution. Equilibrium data were analyzed using Langmuir, Freundlich, and Temkin isotherm models to elucidate changes in adsorption capacity and surface energetics. Ball milling increased the Langmuir maximum adsorption capacity (qmax), from 159.4 to 1027.0 mg/g for PAC-VBM and from 305.7 to 863.6 mg/g for PAC-MBM. Comparative model analysis revealed a mechanistic transition induced by HEBM. Unmilled carbons showed adsorption behavior governed by energetic heterogeneity and coverage-dependent heat variation, with the Temkin model providing the best fit. After milling, adsorption shifted toward a more site-accessible, capacity-dominated regime, with improved Langmuir representation and diminished Freundlich heterogeneity. Despite the substantial increase in capacity, affinity constants decreased, indicating that adsorption enhancement was primarily driven by increased site accessibility rather than stronger binding energy. These results demonstrate that HEBM reorganizes the distribution of effective adsorption energies, shifting BPA adsorption from an energy-controlled to an accessibility-controlled regime. The integration of multiple isotherm models offers a strong mechanistic framework for understanding structure-performance relationships in mechanically activated carbon adsorbents.
- Antonio Ilderlanio de Sousa Leite
- Ricardo de Lima Isaac