The Preparation Of Iron And Cobalt-doped Nano-TiO₂ And Their Application In The Treatment Of Textile Dyeing Wastewater

In this paper, we studied the preparation and the photocatalytic properties of iron and cobalt-doped nano-Ti02 to modify the photocatalytic activity. Pure nano-TiO2, Fe-TiO2, Co-TiO2 and Fe-Co-TiO2 were prepared by Sol-Gel method and were characterized by XRD, UV-Vis, XRF, SEM and Nitrogen adsorption-desorption. The photocatalytic activity was measured by the degradation of the Rhodamine B solution under UV irradiation. We also researched the preparation conditions such as calcination temperature, calcination time and doping amount of Fe and Co impacting on the photocatalytic activity to determine the best preparation. The results showed that the samples which were made under the best preparation conditions were all anatase type. Doping appropriate amount of Fe and Co can inhibit the growth of grain and promote its phase transition. In addition, absorption intensity and absorption wavelength range of catalysts were enhanced after doping appropriate amount of Fe and Co. After doping appropriate amount of Fe and Co, photocatalytic activity of TiO2 improved significantly. Comparing to other samples,0.07%Fe-0.1%Co-TiO2 had the best photocatalytic activity. Under UV irradiation, the degradation rate of Rhodamine B treated by 0.07%Fe-0.1%Co-TiO2 was 96.99%.We also used flocculation method and nano-TiO2 photocatalytic oxidation technology to treat textile dyeing wastewater and studied the photocatalytic degradation of textile dyeing wastewater processed by catalysts which was evaluated by the COD removal rate of textile dyeing wastewater. We researched the factors such as the amount of catalyst, pH and light source impacting on the degradation of textile dyeing wastewater and measured the recyclability of 0.07%Fe-0.1%Co-TiO2. The results showed that the COD removal rate of textile dyeing wastewater was the highest after being treated by 0.07%Fe-0.1%Co-TiO2. Under UV and visible light irradiation, the COD removal rate of textile dyeing wastewater was respectively 79.3% and 49.5%. The COD of the textile dyeing wastewater which has been treated reached the emission requirement of Emission Standard of Water Pollutants from Textile Dyeing Industry (GB 4287-2012). Further more, the recyclability of 0.07%Fe-0.1% Co-TiO2 was good. Its photocatalytic activity reduced insignificantly after being used multiple times.