Heavy metal removing by modified bentonite and study of catalytic activity

Due to the high hydrophobicity and surface area, clays are efficient adsorbents for the removal of liquid impurities and purification of gases when they are modified. In this work, bentonite was modified with imidazole and imidazolium groups and resulting clays were characterized by different techniques such as 1H NMR, 13C NMR, TEM, SEM, XPS, TG, and FT-IR. Applications of these clays were studied in the removal of Co, Cu, and Pb in the wastewater. Effects of contact time, pH, initial heavy metal ions concentration, and kinetic were investigated. The catalytic activity of the metals adsorbed by imidazole modified bentonite was studied in A3 coupling reactions of various amines, aldehydes, and alkynes. •Synthetic strategy by the modification of the bentonite by imidazole and imidazolium groups.•Applications of these clays were studied in the removal of Co, Cu, and Pb in water.•Kinetic studies indicated imidazole modified has higher efficiency in heavy metal removal than imidazolium modified one.•These materials indicated good adsorption efficacy in the heavy metal ion adsorption of industrial wastewaters.