Adsorptive removal of crystal violet dye from aqueous solutions utilizing fox nutshell activated carbon (FNAC)

Over the past few years, environmental concerns regarding dye contamination have grown. Removing dye from wastewater from industry is crucial for environmental sustainability. The removal of crystal violet (CV) dye has been reported using a variety of activated carbons made from solid waste materials, however, these materials have very low adsorption capacities. Fox nutshell, an agricultural byproduct, is widely available in India. Its fibrous texture and high cellulose, hemicellulose, and lignin content make it ideal for dye adsorption. By sodium hydroxide activation followed by carbonization at 600 degrees C, fox nutshell was converted into low-cost fox nutshell activated carbon (FNAC). The removal of CV dye was achieved through its adsorption on FNAC. A porous framework with 2176.6 m2/g 2 /g surface area and 2.24 nm average pore diameter was discovered in the FNAC using SEM, and BET investigations. FTIR analysis shows the presence of the -OH, C=O, C=C, and -COOH functional groups on the surface of FNAC. The adsorption system adhered to a pseudo-second-order kinetic model, with the equilibrium time being determined at 90 minutes. The Langmuir model accurately simulated the adsorption isotherms. The optimum pH for CV (500 mg/l) adsorption onto FNAC (0.09 gm/100 ml) was 6.0, with an adsorption capacity of 454.6 mg/g at 25 degrees C. Negative Delta G degrees and Delta H degrees indicate spontaneous CV adsorption onto FNAC, decreasing with temperature.