Removal of methyl blue and malachite green from water using biodegradable magnetic Tamarindus Indica fruit seed biochar: Characterization, equilibrium study, modelling and thermodynamics

The removal of hazardous dyes from water by magnetic biosorbents has received a lot of interest in recent studies. This is because they are inexpensive and simple to separate from the solution phase. In this study, nano-magnetic Tamarindus indica fruit seed biochar was combined with iron to create a green nano-magnetic/ biochar (BC) composite (nM-BC). Compared to unmodified biochar, modified biochar composite significantly improved the ability to adsorb methyl blue (MB) and malachite green (MG). The Dubinin-Radushkevich, Scathard, Freundlich, Langmuir, and Temkin models were used to analyze the adsorption equilibrium data, and the Langmuir isotherm (R2 =0.952–0.995) provided a good match to the results. Saturated BC adsorption capacities for MB and MG were 3.055 mg/g and 5.577 mg/g, respectively, while nM-BC values for MB and MG were 3.326 mg/g and 20.408 mg/g, respectively. The adsorption process is accurately described by the pseudo-second-order kinetic model. BC and nM-BC both passed four reusability tests. Utilizing FT-IR and SEM instruments BC and nM-BC were characterized. The study demonstrates that biochar can be enhanced with nano-iron which has a potent ability to remove dyes utilizing a green manufacturing approach.