RESEARCH ARTICLE Removal of amoxicillin from simulated hospital effluents by adsorption using activated carbons prepared from capsules of cashew of Para Diana Ramos Lima 1 & Eder C. Lima 1,2,3 & Cibele S. Umpierres 3 & Pascal Silas Thue 3 & Ghadir A. El-Chaghaby 4 & Raphaelle Sanches da Silva 2 & Flavio A. Pavan 5 & Silvio L. P. Dias 2,3 & Camille Biron 1 Received: 25 January 2019 /Accepted: 26 March 2019 # Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract High-surface-area activated carbons were prepared from an agroindustrial residue, Bertholletia excelsa capsules known as capsules of Para cashew (CCP), that were utilized for removing amoxicillin from aqueous effluents. The activated carbons were prepared with the proportion of CCP:ZnCl 2 1:1, and this mixture was pyrolyzed at 600 (CCP-600) and 700 °C (CCP700). The CCP.600 and CCP.700 were characterized by CHN/O elemental analysis, the hydrophobic/hydrophilic ratio, FTIR, TGA, Boehm titration, total pore volume, and surface area. These analyses show that the adsorbents have different polar groups, which confers a hydrophilic surface. The adsorbents presented surface area and total pore volume of 1457 m 2 g -1 and 0.275 cm 3 g -1 (CCP.600) and 1419 m 2 g -1 and 0.285 cm 3 g -1 (CCP.700). The chemical and physical properties of the adsorbents were very close, indicating that the pyrolysis temperature of 600 and 700 °C does not bring relevant differences in the physical and chemical properties of these adsorbents. The adsorption data of kinetics and equilibrium were successfully adjusted to Avrami fractional- order and Liu isotherm model. The use of the adsorbents for treatment of simulated hospital effluents, containing different organic and inorganic compounds, showed excellent removals (up to 98.04% for CCP.600 and 98.60% CCP.700). Keywords Adsorption . Bertholletia excelsa capsules . Activated carbon . Amoxicillin, emerging contaminant Introduction The release of pharmaceuticals to natural waters is one of the significant environmental concerns in the last days (Sophia et al. 2016; Sophia and Lima 2018), because these compounds could threaten the water resources (Abazari et al. 2019). These releases come from the pharmaceutical industries, excretions of humans and livestock animals, and also hospital effluents (Sophia et al. 2016; Abazari et al. 2019). Among the pharma- ceuticals, the antibiotic class is used with high frequency, and they could generate microbial resistance even in small amounts found in the waters (Bondarczuk and Piotrowska- Seget 2019; Qiu et al. 2019). The municipal wastewater treatment plants are not always able to remove antibiotics and other emerging contaminants (Krzeminski et al. 2019) altogether. In this way, tertiary water treatments methods are required (McConnell et al. 2018; Le et al. 2018; Moreira et al. 2015). The methods for treatment of water contaminated with antibiotics are removed by using membrane bioreactor systems (Le et al. 2018), photocatalytic methods (Moreira et al. 2015; Li and Shi 2016; Lu et al. 2019), Responsible editor: Tito Roberto Cadaval Jr Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11356-019-04994-6) contains supplementary material, which is available to authorized users. * Eder C. Lima eder.lima@ufrgs.br 1 Graduate program in Metallurgical, Mine and Materials Engineering (PPGE3M). School of Engineering, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, Porto Alegre, RS 9500, Brazil 2 Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, P.O. Box 15003, Porto Alegre, RS 91501-970, Brazil 3 Graduate program in Science of Materials (PGCIMAT). Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, Porto Alegre, RS 9500, Brazil 4 RCFF-Agricultural Research Center, Giza, Egypt 5 Federal University of Pampa (UNIPAMPA), Bagé, RS, Brazil Environmental Science and Pollution Research https://doi.org/10.1007/s11356-019-04994-6