Sorption Extraction of Zn2+ Ions from Aqueous Environment with Zoo Compost of Black Soldier Fly

Abstract

The paper presents the results of experimental studies to determine the possibility of sorption extraction of zinc ions (Zn2+) from aqueous environment using the zoo compost of the Black soldier fly (Hermetia illucens). The indicators of zoo compost on the content of biogenic elements in it are given. The adsorption of zinc ions was studied on model solutions using a static method at a temperature of 20 °C and a sorption interaction time of 24 h. The concentration of Zn2+ ions in the initial and purified solutions was determined photocolorimetrically at a wavelength of ƛ = 213.8 nm. The obtained values of the concentrations of zinc ions in solutions before and after the adsorption process were used to determine the sorption capacity of the material (A). It was found that the maximum sorption capacity of the zoo compost for zinc ions is 0.149 mmol/g. To determine the mechanism of the process, the resulting adsorption isotherm was processed using the Langmuir, Freundlich, and Dubinin-Radushkevich models. It is established that the adsorption process is well described by the Langmuir isotherm, which indicates the course of monomolecular adsorption. The necessary constants and thermodynamic parameters are calculated. The Gibbs energy of the adsorption process is determined, the negative value of which indicates the spontaneous flow of the process.