Study of phenol adsorption by modified birch leaves: Preparation and adsorption characteristics

Abstract

Aim and Scope: One of the priority areas of chemistry and ecology is the receipt of highly effective, cheap, and accessible sorption materials. The waste from industrial and agricultural production is considered as the sources of such sorption materials. In connection with the foregoing, modified sorption materials based on birch leaves (Betula pendula) were prepared by surface treatment with the solutions of sulfuric acid at the concentrations of 1–5% and their sorption properties were studied with respect to phenol in the static adsorption regime.[1] Material and Methods: The study of the sorption properties of materials was carried out in the static adsorption regime on model systems. Result and Discussion: Sulfuric acid-modified birch leaves were obtained by the processing of material surface with the solutions of sulfuric acid at the concentrations of 1, 2, 3, 4, and 5%. Sorption properties of native and modified sorption materials were studied with respect to phenol in the static adsorption regime. They created the isotherms of phenol sorption by studied materials. It was found that the process of phenol sorption by native birch leaves at the temperature of 25°C is best described by the Dubinin-Radushkevich equation, and at 35°C and 45°C by Langmuir’s equations, while the process of phenol sorption by modified birch leaves at all three temperatures is best described by Temkin’s equations.Conclusion: Thermodynamic constants of the phenol sorption process by native and modified birch leaves have been calculated. It has been established that the processes of phenol sorption by native and modified birch leaves refer to physical processes (according to modulus: E < 8 kJ/mol, ΔH < 100 kJ/mol, ΔG < 20 kJ/mol) with maximum sorption capacities of 0.06 mmol/g and 0.128 mmol/g, respectively, at 25°C.