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sexta-feira, 13 de julho de 2012

New Nanocatalyst Used to Purify Wastewater without Visible Light

TEHRAN (INIC)- Iranian researchers succeeded in the production of a new type of nanocatalyst that needs no visible light to remove colorants from wastewater.

Various methods have so far been proposed for the removal of colorants from wastewater, each of which has its own specific limitations. One the most well-known methods is the use of titanium oxide (TiO2) nanostructures as photocatalysts, which has some limitations due to the need for sunlight and visible light.
By carrying out studies on nanocatalysts, the Iranian researchers in Shiraz University used Pd/HAP/Fe3O4 as an appropriate nanocatalyst in order to remove azo dyes. The researchers synthesized Pd/HAP/Fe3O4 nanocatalyst, and they studied its performance in the water containing colorants.

They believe that in order to remove the colorant, the nanocatalyst firstly reacts with the oxygen dissolved in water in acidic atmosphere, and hydro-peroxide is formed. The obtained hydro-peroxide reacts with azo dye in the presence of HAP catalyst, and it results in the decomposition of the azo dye.

The results of the research show that the reaction of dye removal indicates the high efficiency of the nanocatalyst. Among the advantages of the nanocatalyst, mention can be made of high catalytic activity, ability to extract catalyst from the solution through magnetic methods, appropriate stability, ability to be recycled, and the lack of need for light or any other harmful substance.

The research has been published in detail in January 2012 in Journal of Hazardous Materials, vol. 201-202, pp. 125-131.