Potassium Hydroxide-Activated Formaldehyde Film Resin Residue for Methyl Violet Adsorption– Batch and Dynamic Studies

Re-purpose of formaldehyde film resin residue is a sustainable solution to abate harmful effects to human and environment. The present work was aimed to evaluate the adsorption properties of activated carbons derived from formaldehyde resin film for methyl violet removal. The activated carbons were prepared via potassium hydroxide activation with different weight ratios (KOH-to-resin) of 0.5, 1 and 2 to yield surface area in the range of 300 to 476 m²/g. The adsorption performance was evaluated through isotherm kinetic, thermodynamic and dynamic studies. The dye capacities of activated carbons are in the order of FR2> FR1> FR0.5. The equilibrium data fitted well with the Langmuir model, while the kinetics could be described by the pseudo-second order model. The adsorption capacity of FR2 increased with increasing temperature suggesting an endothermic and spontaneous process at high solution temperature. The dynamics of methyl violet adsorption obeyed the Thomas and Yoon-Nelson models. The formaldehyde film resin can be potentially valorized into activated carbons for dye adsorption from wastewater.