Pigments Templated TiO₂Aerogels For Photocatalytic Treatment Of Cr（Ⅵ）and Coking Wastewater

The wastewater containing chromium from related chemical industry will do immeasurable harm to the natural environment and human health. Chromium pollution control is imminent. This article will take aerogel materials, which are synthesized and templated by pigments,for photocatalytic treatment of Cr(VI):First of all, we screen out the best one among a series of chlorophyll of aerogel materials synthesized under different conditions according to experiments, and the best one from aerogel materials synthesized by different pigments(red cabbage、red radish、safflor yellow, purple sweetpotatoes, gardenia yellow, gardenia blue). Then two materials (TiO2-chlorophyll and TiO2-red cabbage) are used to perform systemic experiment respectively, discussing the effects of reaction time、catalyst dosage、initial concentration solution and light source. Results indicate:The two materials show high catalytic activity. After the reactions have lasted one hour under UV light to20mg/L Cr(VI) solution, the reduction rate is as high as98%.Experiment also be conducted under the simulated sunlight and visible light. The reduction rate can still reach more than50%after6hours’reaction under visible light. The effects are much better than commercial P25material.Coking wastewater is one of the organic industrial wastewater to be hardly treated in the world. But the current treatment methods can not receive effective results. So efficiency and cheap processing methods is the focus of many scholars studies. In this paper, we treat it through coagulation, biochemical, ozone oxidation and photochemical catalysis method. Results indicate:The degradation rate of COD and NH3-N are all less than60%by the means of coagulation, biochemical and ozone oxidation. And they exist many problems, for example poor effects、instability、 secondary pollution and so on. However,we utilize chlorophyll of aerogel materials made by ourselves for photocatalytic degradation of the coking wastewater. After photocatalytic reaction lasts one hour with20mg photocatalyst X, the degradation rate of COD and NH3-N is as high as80%and88.4%respectively.The treatment effect is very ideal. It could provide technology support and reference for the scale treatment of the coking wastewater, has a great application value.