Removal of Phenol from Wastewater Using Fenton-Like Reaction over Iron Oxide–Modified Silicates

Iron-containing active phase was deposited on natural layered silicate (vermiculite) using several techniques such as ion exchange, precipitation, and forced hydrolysis during hydrothermal digestion. Tuning of the synthesis conditions resulted in preparation of the catalysts with different loading of active phase and physicochemical properties. The composite materials were characterized with respect to their structure (X-ray diffraction), agglomeration state of Fe (diffuse reflectance UV-vis spectroscopy), and chemical composition. Catalytic tests were performed in semi-batch reactor under atmospheric pressure. Aqueous solution of phenol was used as a model industrial effluent, and hydrogen peroxide was added as an oxidant. Spectral techniques were used for identification of intermediate oxidation products. Spent catalysts were also characterized, and structural and chemical changes were determined, e.g., leaching degree of active phase