Аннотация:The catalytic activity of natural bentonite clay containing 98 wt % montmorillonite is studied. The
clay is modified with sodium metasilicate solution through reaction of oxidative destruction of organic azo dyes using hydrogen peroxide according to the Fenton–Raff mechanism in neutral medium. It is shown that the high catalytic activity of natural bentonite clay is due to presence of iron cations contained in the montmorillonite structure. In addition, protonated silanol and aluminol groups available at the surface of the ribs of the aluminosilicate layers act as Brønsted acid centers. The degree of conversion of Synozol Blue azo dye having an initial concentration of 20 mg/L in solution was 99% within 4–6 min of contact time at room temperature. The resulting material has good filtration properties and it can be recommended to treat wastewater to remove organic substances.