Harnessing alkali assisted Calotropis gigantea leaf as phytosorbent for removal of crystal violet from water.

This study investigates using activated Calotropis gigantea (ACG) leaves as a natural, cost-effective phytosorbent for the sequestration of crystal violet (CV). The various techniques, including fourier transform infrared (FTIR), Powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM), dynamic light scattering (DLS), Brunauer-Emmet-Teller, and UV-Vis spectrophotometer, were used to illustrate the efficiency of the phytosorbent. The adsorption behavior of the biosorbent was examined by varying several parameters, such as pH, dye concentration, adsorbent amount, thermodynamics, and equilibrium time. Adsorption isotherms and kinetic models were also fitted. The maximum adsorption capacity of CV on ACG was found to be 111.11 mg/g achieved at 35 °C or 308.15 K. The calculated thermodynamic parameters, such as ΔH and ΔS for CV uptake on the adsorbent surface, come out to be 22.397 kJ/mol and -100.25 J/mol/K, respectively. The positive enthalpy change, confirms the endothermic nature of the adsorption process. The negative values of ΔG confirmed the spontaneous nature of the adsorption process. The recyclability of the adsorbent is also good after four cycles of regeneration, and the adsorbent has ∼80% removal with the real waste water sample. Overall, phytosorbents based on dried Calotropis gigantea leaves demonstrate strong potential as an effective biosorbent for the adsorption of CV via contaminated water.