Conversion of char from pyrolysis of plastic wastes into alternative activated carbons for heavy metal removal Pereira, Ledicia Castillo Ramos, Ventura Calero De Hoces, Francisca Mónica Blázquez García, Gabriel Rodríguez Solís, Rafael Martín Lara, María Ángeles Char Activated carbon Plastic waste Adsorption Heavy metals Agrochemicals The authors acknowledge the Ministry of Science and Innovation and the Research State Agency 10.13039/501100011033, and the European Union Next Generation EU/PRTR, Projects Oriented to Ecological and Digital Transition 2021 for the project TED 2021-130157 B–I00 CARBOPLASTIC. They also thank the support provided for the external services of investigation of the University of Granada (Centro de Instrumentación Científica. CIC). Funding for open access charge: Universidad de Granada/CBUA. The valorization of post-consumer mixed plastics in pyrolysis processes represents an abundant reservoir of carbon that can be effectively converted into useful chars. This process not only holds appeal in terms of improving plastic waste concerns but also contributes to the reduction of greenhouse gas emissions, thus aligning with the principles of a circular economy paradigm. In this study, the char produced from the pyrolysis of post-consumer mixed plastic waste has been activated with Na2CO3, KOH, NaOH, and K2CO3 to improve the textural, structural, and composition characteristics, leading to improved adsorption capability. These characteristics were studied by N2 adsorption-desorption isotherms, scanning electron microscopy, elemental and immediate analysis, and X-ray photoelectron spectroscopy. The developed surface area (SBET) was 573, 939, 704 and 592 m2 g−1 for Na2CO3, KOH, NaOH and K2CO3 activated carbons, respectively. These activated chars (ACs) were tested for the adsorption of heavy metals in both synthetic waters containing Pb, Cd, and Cu and industrial wastewater collected at an agrochemical production plant. Na2CO3-AC was the best performing material. The metal uptake in synthetic waters using a batch set-up was 40, 13 and 12 mg g−1 for Pb, Cd and Cu. Experiments in a column set-up using Na2CO3-AC resulted in a saturation time of 290, 16, and 80 min for Pb, Cd, and Cu synthetic waters, respectively, and metal uptakes of 26.8, 4.1, and 7.9 mg g−1, respectively. The agrochemical effluents, containing mainly Cr, Cu, Mn, and Zn were tested in a plug-flow column. The metal uptake notably decreased compared to synthetic water due to a competition effect for active sites. 2024-03-01T10:15:41Z 2024-03-01T10:15:41Z 2024-02-24 journal article Pereira, Ledicia et al. Conversion of char from pyrolysis of plastic wastes into alternative activated carbons for heavy metal removal. Environmental Research 250 (2024) 118558. https://doi.org/10.1016/j.envres.2024.118558 https://hdl.handle.net/10481/89711 10.1016/j.envres.2024.118558 eng info:eu-repo/grantAgreement/EC/NextGenerationEU/TED 2021-130157 B–I00 http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier