Adsorption of Cationic Dyes onto Bentonite

摘要

The removal of dyes from wastewater effluents is a challenging issue in environmental engineering. Among the techniques employed, adsorption technology is generally considered highly efficient and industrial bentonite clay has been extensively used for this purpose. The aim of this study is the systematic and comparative presentation of the available information on the adsorption of cationic dyes from aqueous solution onto raw or modified bentonites. The review outlines the bentonite modification methods and presents a list of isotherm and kinetic models used for the interpretation of adsorption. A brief description of each article and information on the type and the characteristics of the adsorbent are given in tables. In addition, data is included concerning single and competitive adsorption of basic dyes on bentonite. Experimental conditions are outlined and the kinetic and isotherm parameter values of proposed models are listed in tables. The effect of various factors on the adsorption efficiency is discussed and the most important aspects referring to adsorption thermodynamics are reviewed.