Attenuation of Carcinogenic Cr (VI) Using Tea Waste-Anthracite @ Chitosan Composite(Tw-An@Cs) from Wastewater; Statistical Analysis

Abstract Locally available tea waste was used in this work as a precursor for the tea waste-anthracite @ chitosan (Tw-An@Cs) composite material, which isolates Cr(VI) from wastewater. The precursor and (Tw-An@Cs) composite were fully evaluated using N 2 adsorption-desorption surface area, FT-IR, XRD, and SEM techniques. The full Cr (VI) uptake study was conducted utilizing the batch adsorption approach under various operating conditions. With a maximal monolayer coverage of 68.49 mg/g, the results showed that Langmuir gave the best description of Cr (VI) ion adsorption. The pseudo-second-order mode provided a good fit to the sorption kinetics models. Furthermore, the adsorption of Cr (VI) was influenced by numerous pathways, as confirmed by the Boyd, Elovich, and intraparticle diffusion models. The negative ΔH (− 17.207 kJ/mol) suggested the chemisorption of Cr(VI), indicating an exothermic adsorption mechanism. From − 33.317 to − 35.833 kJ/mol at the studied temperature range, the negative value of ΔG confirms the process’s potential as a spontaneous sorption reaction. Coefficient determination (R 2 ), adjusted R 2 , and expected R 2 were 0.9666, 0.93321, and 0.808, respectively, based on the results of the ANOVA. After four successive cycles of adsorption, the resulting (Tw-An@Cs) composite showed a favorable degree of reusability and a significant sorption affinity for Cr (VI) ions. Furthermore, the (Tw-An@Cs) composite can be used as a recyclable and eco-friendly sorbent to remove Cr (VI) from wastewater. Highlights Sustainable Tea Waste-Anthracite Chitosan Composite for Cr (VI) removal. Kinetic data fits well with the pseudo-second-order model. ANOVA analysis was conducted. Langmuir isotherm best describes Cr (VI) sorption in both linear/nonlinear models. The sorption process is exothermic and spontaneous, with high reusability potential.