Study On Zhidan Clay Modified And The Application

The thesis focus on acid activations process of bleaching-clay, which were collected from ZhiDan, Shaanxi province was investigated. The activiated bleachin-clay was charicaterized. The best activation process was obtained via the optimization experiment. The as prepared activiated-bleaching clay was used to adsorb the Pb²⁺ and treat the wastewater,etc. The as-prepared activated-bleaching clay was also used as the carrier to prepare the Gd, Cd codoped titiana dioxide. The photocatalytica performance of as-synthesized Gd,Cd codoped TiO₂/activiated bleaching clay photocatalyst was investigated. It's performance on the treatment of the refinery wastewater was explored as well.Acid activation process of bleaching-clay, which were collected from ZhiDan, Shaanxi province was used as starting material to prepare the high performance activiated bleaching clay. Experimental results showed that the nitric acid activation process is applicable to ZhiDan acid activated bleaching-clay and satisfactory properties of the activated material can be obtained under controlled process parameters. The final activated process showed the best parameters of quality concentration,activation temperature and activation time, was 30%, 85℃, 5h, recpectively. The activated bleaching clay showed good adsorption activity on lead ion of wastewater.Decompression distillation process was employed to treat the refinery wastewater. The temperature and the dosage of activated-bleaching clay on removal efficiency on COD of refinery wastewater was discussed .The experimental results indicated that the activated-bleaching clay assisted ddecompression distillation process shows better effect on the treatment of refinery-oil wastewater-COD_Cr value decreased from 1809.5mg/L to lower than 60mg/L ( the total removal efficiency was beyond 97%). The water quality of the treated wastewater can reach the emission standard of industrial wastewater. Using tetrabutyltitanate, gadolinium nitrate and cadmium nitrate as raw materials, Gd-Cd co-doped nanometer TiO₂ have been successfully synthesized by a sol-gel process, and characterized by XRD, XPS and UV-vis techniques. Rhodamine B was chosen as model pollutant to evaluate photocatalyst's activity. The XRD analysis result indicated that the as-synthesized samples were all anatase nanometer TiO₂. UV-vis absorption spectrum indicated after Gd-Cd co-doping TiO₂ had strongger absorption in UV region, and had obvious response to visible light. Photocatlytic expenriment results showed when the gadolinium and cadmium doping quantity approximately was 0.2% and 0.3% respctively, nanometer TiO₂ had the better activity.