Adsorption of polystyrene nanoplastics on sawdust-based activated carbons
The rapid increase in global plastic production has led to the significant accumulation of plastic waste in aquatic environments. Nanoplastics, defined as particles <1 μm in size, have been detected in various water bodies, raising environmental and health concerns due to their persistence and ch...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universidad Autónoma de Madrid |
| Repositorio: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.uam.es:10486/717357 |
| Acceso en línea: | http://hdl.handle.net/10486/717357 https://dx.doi.org/10.1016/j.jwpe.2024.106891 |
| Access Level: | acceso abierto |
| Palabra clave: | Adsorption Breakthrough Curves Polystyrene Nanoplastics Sawdust-Based Activated Carbon Waste Valorization Water Treatment Química |
| Sumario: | The rapid increase in global plastic production has led to the significant accumulation of plastic waste in aquatic environments. Nanoplastics, defined as particles <1 μm in size, have been detected in various water bodies, raising environmental and health concerns due to their persistence and challenges in management. This research examines the adsorption efficiency of sawdust-derived activated carbons (ACs) for polystyrene nanoplastics (PSNPs). Several agents were investigated in chemical activation, including the use of phosphoric acid (H3PO4), ferric chloride (FeCl3), and potassium hydroxide (KOH). Different carbonaceous adsorbents with varying textural properties and points of zero charge (pHPZC) were synthesized. S-Char exhibited no porosity and a basic surface (pHPZC of 10.3). S-H3PO4 achieved a BET surface area of 837 m2·g−1, predominantly mesoporous, and had an acidic surface (pHPZC of 3.0); S-FeCl3 demonstrated a BET surface area of 451 m2·g−1, mainly microporous, with a pHPZC of 5.9; S-KOH presented the highest BET surface area of 1037 m2·g−1, meso-microporous, and a pHPZC of 6.3. The adsorption kinetics were best represented by the pseudo-second-order model, indicating that the adsorption process is predominantly governed by chemical interactions. Notably, the adsorption capacity of S-KOH increased with temperature, underscoring the endothermic nature of the process. Adsorption isotherms of S-KOH, determined at temperatures of 25, 50, and 75 °C, conformed well to the Sips model, with a maximum adsorption capacity of 40.84 mg·g−1 at 75 °C. The enthalpy and entropy of adsorption were calculated to be 6.99 kJ·mol−1 and − 3.27 J·mol−1·K−1, respectively, suggesting an endothermic reaction and a decrease in randomness at the solid-liquid interface during adsorption. Breakthrough curves were generated at various adsorption temperatures, fitting accurately to a logistic-type equation representative of the Bohart-Adams, Thomas, and Yoon-Nelson models |
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