Synthesis of tea waste/Fe3O4 magnetic composite (TWMC) for efficient adsorption of crystal violet dye: Isotherm, kinetic and thermodynamic studies

We report the synthesis and application of tea waste/Fe3O4 magnetic composite (TWMC) for adsorption of crystal violet (CV) dye from aqueous solution. The best conditions were determined for 98.7% removal of CV dye using an adsorbent dosage of 1.0 g L−1, contact time of 90 min, an initial dye concentration of 100 mg L−1, and an initial pH of 7 at 298 K. In correlation with the results of kinetic study, the pseudo- second-order model fit for this study. The isotherm data of equilibrium study fitted well to Langmuir isotherm model. The composite's highest adsorption capacity for CV dye was 333.33 mg g−1. CV adsorption onto TWMC was heat releasing and spontaneous process. Adsorption of CV dye from aqueous solutions on TWMC was significantly favored, according to the findings of thermodynamic study. CV dye was effectively removed from aqueous solution, according to a phytotoxicity investigation. The study shows application of waste to useful strategy to synthesize tea waste magnetic composite and its efficiency in removing toxic dye CV from aqueous system. [Display omitted] •Tea waste is utilized for the synthesis of magnetic composite TWMC as adsorbent material.•The batch study confirmed easy separation of toxic crystal violet dye using TWMC with adsorption capacity 333.33 mg g -1.•Cytotoxicity study shows the removal of crystal violet impacts its concentration below the toxicity level.