Adsorbents for iron removal obtained from vermiculite

In presented work, raw, expanded and acid treated vermiculites were used as low-cost and active adsorbents for reducing o f environmental pollution with heavy metals. Acid treatment was performed at elevated temperature (95°C) for 2 and 24 h in solution of HNO 3 . Adsorption capacity towards Fe 3+ was studied in column, semi- b atch and batch mode. It was shown that all samples are effective in removal of heavy metals; however adsorption mechanism is based not only on ion exchange o f interlayer cations but also precipitation/ deposition processes. Starting material a nd modified samples as well as spent adsorbents were characterized with respect to the vermic ulite structure using X-ray diffraction metho

Vermiculite-based catalysts for oxidation of organic pollutants in water and wastewater

In presented work natural expanded vermiculite was used as a starting material for synthesis of Fe-doped cataly sts. Material was modified with increasing amount of Fe by ion-exchange and precipitation of iron oxide. Composite materials were characterized with respect to their stru cture (X-ray diffraction, Infrared spectra using Diffuse Reflectance), agglomeratio n state of Fe (Ultraviolet-Visible spectra using Diffuse Reflectance) and chemical composition. Activity in H 2 O 2 decomposition as well as in phenol oxidation was studied in liquid phase at atmosphe ric pressure and temperature up to 70 °C. It was shown that doping with Fe increases ca talytic activity. However, excess of iron result ed in formation of undesired side-products