Removal of pentachlorophenol from aqueous solutions by dolomitic sorbents

Abstract

The partial decomposition of dolomite carried out within the temperature range 600–1000 °C provides new sorbents, called dolomitic sorbents. Their surface properties and identification by X-ray diffraction are discussed. The lowest specific surface area value was found for the raw dolomite, while the highest value was achieved by the D-1000 sample. The adsorption equilibrium of pentachlorophenol from aqueous solutions on the examined sorbents was investigated at 30, 40, and 50 °C via a bath process. Langmuir, Freundlich, Langmuir–Freundlich, and Redlich–Petersen models were fitted to experimental equilibrium data, and their goodnesses of fit are compared. The adjustable parameters of Langmuir–Freundlich and Redlich–Petersen isotherms were estimated by nonlinear least-squares analysis. Langmuir and Freundlich models were found insufficient to explain the adsorption equilibrium, while Langmuir–Freundlich and Redlich–Petersen isotherms provide the best correlation of the pentachlorophenol adsorption onto dolomitic sorbents.