Removal of Methyl Violet Dye from Aqueous Solution by sf Platanus Carpinifolia Tree Leaves as Highly Efficient Sorbent: Multivariate Optimization, Isotherm Modeling, and Kinetic Studies

Abstract

This study introduces a novel and highly efficient biosorbent called Platanus Carpinifolia tree leaves to remove Methyl violet from aqueous solution. A Box-Behnken design of experiment based on three main factors (initial concentration ( C d ), sorbent amount (S), and pH) through the response surface methodology approach was chosen to model the removal efficiency (R%) of Methyl violet. The optimum conditions were found from the obtained model as C d = 500 mg/L and S = 0.11 g/L with no pH significant influences. Langmuir, Freundlich, and Temkin isotherms were applied to scrutinize the equilibrium aspect of biosorption by fitting the adsorption experimental data with isotherms. The adsorbent's maximum capacity uptake ( q max ) was obtained to be 555.5 mg/g from the Langmuir model, which has shown better description of the equilibrium process. Kinetic of biosorption was studied with making use of the pseudo-first order and pseudo-second order models along with intra-particle diffusion. The results showed that the adsorption process behaves in accordance with the pseudo-second order model, and intraparticle diffusion is not solely the rate-limiting step. Regarding the thermodynamical investigation, Δ G°, ΔH ○ , and ΔS°respectively, were predicted to be 1.96, 37.34 kJ/mol, and 132 J/mol. This implies that chemisorption is the predominant portion of adsorption mechanism.