Preparation Of Nano-composite Tio <sub> 2 </ Sub> And Nitro Wastewater Degradation Studies

Nano-TiO₂/Diatomite composite photocatalyst was prepared with tetrabutyltita- nate and diatomite as precursor by sol-gel, The influence of calcinated time, calcinated temperature, the molar ratio of the reactants, the quantity of the catalyst on the as-prepared samples was investigated via XRD, DTA and SEM, and the acting mechanisms of different methods were discussed. The results indicated that the crystalline size of TiO₂ in the composite is 13.32nm, and its specific surface area reached 94.321m²/g. The photocatalytic activity was valuated by the TNT wastewater degradation. The degradation rate of TNT wastewater is 91.44% after 6 hour photocatalytic treatment.The photocatalytic reactor was made with Nano-TiO₂/Diatomite composite photocatalysts. The influence of the weight of photocatalyst, the consistence of wastewater, the number of used to capability on photocatalytic reactor. It was found that the efficiency of photocatalytic reactor was a little lower than Nano-TiO₂/Diatomite composite powders, but much higher than pure TiO₂. The degradation rate of TNT wastewater is 85.32% after 6 hour by reactor treatment. Compare with composite powders using in the wastewater directly, photocatalytic reactor shows furthermore steadier and higher photocatalytic activity in repetitive experiment after using many times. The degradation rate of TNT wastewater after 6 times and 6-hour photocatalytic reactor treatment reduced from 85.32% to 79.8%, and the photocatalytic efficiency of nanometer powder reduced from 91.44% to 47.25%.It can be estimated that photocatalytic reactor avoid the occurrence of defilade among photocatalysts, so the using ratio of lamp-house can be boosted, which makes the photocatalytic activities improved.