Removal of Dyes and Heavy Metals with Clays and Diatomite

In recent years, many researches are focused to use clay and diatomaceous earth like the most and the effective solution to reduce this problem, thanks for their abundance, the cheapness, and the important surface area. This chapter aims to discuss the removal of organic and inorganic pollutants such as dyes (methyl orange, indigo carmine, phenol red, acid brown 75, basic yellow 28, etc.) and heavy metal ions (such as Zn (II), Cd (II), Pb (II), Ni (II), Cr (II), etc.) from water by adsorption on clays and diatomaceous earth. The application of chemical and physical modifications of the functional groups of clay and diatomite enhance their adsorption capacities. The kinetics and the models used to describe the adsorption processes are discussed. The reported results for a variety of clays and diatomite derivatives showed that these materials could be applied successfully for the removal of dyes and heavy metals from wastewater.