In order to prevent contamination of surface and ground water caused by industrial operations, remediation of cyanide containing waste and process waters that today is very needed. The free cyanide form is the most toxic form while iron�cyanide complexes, Fe(CN)63- and Fe(CN)62-,are relatively less toxic. Researchers recently have aroused interest in the study of niobium oxide, which shows a remarkable catalytic activity in different types of reactions (dehydration of alcohols, sugars, oxidation of nitrogen compounds), in its simple form of oxide and salts niobium and combination with other oxides such as titanoniobiatos (HTiNbO5), which possesses properties as a photocatalyst. This study examines novel catalytic systems based on niobium-titania, as an alternative to the removal of free cyanide. These precursors synthesized with NbO3, TiO2, kCO3 and / or KHCO3, titanium lactate, oxalate niobium using synthesis methods as sol-gel, ceramic, citrate and combustion. The catalysts were characterized using FT-IR, XRD, BET and  acidity, we saw differences in the vibrational bands related Nb-O and Nb-O-Nb,  can be attributed to them,   be responsible for photocatalyst activity. The best degradation conditions were obtained, using 2.5g / L of catalyst and pH 9.5,with one yielding  of about 80% of  cyanide removal, when using  solids, which were prepared by ceramic and citrate method, which had basic character, it was confirmed, that this reaction depends on the characteristics of acidity or alkalinity of photocatalyst used. The laminar structure of HTiNbO5 and NaTiNbO5 contributed to achieve of stability, cyanate was the main oxidation product obtained and a 60% decrease in COT.

Effect of synthesis method of niobium-titanium photocatalysts for  free cyanide removal

248th National Meeting (2014)

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