Spent coffee grounds-derived carbon material as an effective adsorbent for removing multiple contaminants from wastewater: A comprehensive kinetic, isotherm, and thermodynamic study
Vedran Milanković, Tatjana Tasić, Snežana Brković, Nebojša Potkonjak, Christoph Unterweger, Danica Bajuk‐Bogdanović, Igor A. Pašti, Tamara Lazarević‐Pašti
Abstract
Environmental contamination from various industrial sources poses a significant global concern, demanding effective remediation strategies. This study investigates the efficacy of spent coffee grounds-derived carbon material in removing various contaminants, including organophosphate pesticides , pharmaceutical residues , and cationic dyes from aqueous solutions. Adsorption experiments were conducted at different temperatures (25 °C, 30 °C, and 35 °C), and the adsorption behavior was analyzed using various kinetic (pseudo-first-order, pseudo-second-order, Elovich, intraparticle diffusion) and isotherm models (Freundlich, Langmuir, Temkin, Dubinin-Radushkevich). Our findings reveal a complex adsorption process involving both monolayer and multilayer adsorption on the heterogeneous surface of the material. Temperature significantly influenced adsorption behavior, affecting maximum capacities and interactions. Using a material concentration of 0.5 mg mL −1 increases adsorption capacities for both pesticides, reaching 92.0 mg g −1 for malathion and 259 mg g −1 for chlorpyrifos adsorption. At a material concentration of 0.1 mg mL −1 , the carbon material exhibited high adsorption capacities for methylene blue , rhodamine B , amoxicillin , and ceftriaxone , reaching values of 2085 mg g −1 , 8250 mg g −1 , 82 mg g −1 , and 181 mg g −1 , respectively. The adsorbent was successfully regenerated using 25 % ethanol solution and reused for at least 10 cycles without significantly impacting the adsorption capacity. These results underscore the potential of spent coffee grounds-derived carbon material as an efficient adsorbent for diverse contaminants, highlighting its promising role in environmental remediation efforts.