Degradation of Congo Red dye on zeolite

The toxicity of a number of dyes, which are common pollutants of natural and wastewater, determines the high importance of their removal by accessible and effective methods. The aim of this work was to study the photodegradation of Congo red solution on modified Ag-containing natural clinoptilolite and gamma-alumina. The porous structure of clinoptilolite was developed by using dealumination with ethylenediaminetetraacetic acid. Utilizing silver nitrate impregnation and its reduction with glucose the silver particles were deposited on the samples. TEM studies confirmed the formation of nanosized silver particles on the surface of both samples. Photocatalytic dye conversion tests showed that the natural zeolite modified with nanosilver (1 wt. %) demonstrates significant photocatalytic activity, which is only slightly inferior to the activity of silver-containing alumina.