Application of Carbon-Containing Sorption Material for Wastewater Purification from Methylene Blue Dye

Abstract

The equilibrium sorption of methylene blue coloring agent on carbon-containing sorption materials has been studied. As an initial sorbent the carbon-containing material, obtained by thermal processing of oil extraction industry waste kieselguhr sludge at temperature 500 ºC in conditions of lack of oxygen, notionally named TKS500, was used. TKS500 was activated by treating it with 30% nitric acid solution and 1 M sodium hydroxide solution. It has been demonstrated that the dye’s sorption isotherms for the initial and for the activated TKS500 samples are of the S-type. In low concentrations range of the dye solution a monolayer is formed. With the further increase of the dye content, after monolayer formation the methylene blue molecules are extended to dimer molecules and the sorption becomes polymolecular, which is shown in the isotherm as a sharp increase of sorption capacity. This is characteristic for both the initial sorption material, and for the material, modified with sodium hydroxide and nitric acid solutions. In the low concentrations range of the dye solution the sorption isotherms for the initial TKS500 and for the TKS500, modified with HNO3 solution, are described with Freundlich model’s equations, and the sorption isotherm for the TKS500, modified with NaOH solution, is described with Temkin model’s equation. It has been determined that the maximum sorption capacity (0.244 mmol/g) is possessed by the carbon-containing sorption material TKS500, activated with the 30% nitric acid solution.