Study On The Characteristic Of Photocatalytic Degradation And Reduction Of 3,4-Dichloronitrobenzene

TiO₂ photocatalytic technology with high efficiency, low energy consumption, easy operation, mild reaction conditions and wide application, could reduce the secondary pollution and other prominent features in the treatment of organic wastewater of concern. In addition, clean production and the promotion of energy conservation required the synthesis process to explore a new type of source reduction in the production of pollutant.The optimum conditions for influence factors of heterogeneous photocatalysis using TiO₂ to degrade 3,4-dichloronitrobenzene were as follows: under the condintion of 150W UV lamp, 3,4-dichloronitrobenzene degradation rate was up to 75.6% after reaction 5h; The highest reaction rate was at the pH of 4, the removal rate of 3,4-dichloronitrobenzene was 84.9% at using 250W UV lamp as light source for 5h; When the amount of air leads to 0.2m3/h (the dissolved oxygen 8.7mg/L), the substrate degradation rate was 93.7%; 60mg/L of 3,4-dichloronitrobenzene was the most suitable concentration for the photocatalytic treatment; When dosage of catalyst was 2g/L, the degradation rate constant up to 0.3302, and 5h reaction made the 3,4-dichloronitrobenzene removal rate 93.2%; Self-prepared N-doped catalyst was superior to other catalysts, and 3,4-dichloronitrobenzene degradation rate was reached to 85.4% using 250W UV lamp as light source for 5h.In the Photocatalytic reduction of 3,4-dichloronitrobenzene, the solvent methanol as a good hole scavenger, reacted for 20h leading the yield to 61.22%; The dosage of catalyst is 6g/L made the 3,4-dichloroaniline production rate 57.17%; Non-ionic surfactant Subwet159 could promote the photocatalytic reduction, while the cationic surfactant CTAB was on the role of the reduction of obstacles; The initial concentration 10g/L mean to the most efficient photocatalytic reduction, after reacting for 12h which could gain the yield of 71.3%; The presence of dissolved oxygen played a lot of obstacles in photocatalytic reduction, the higher the radiation intensity of light, the more removal gained related; In the reduction reaction, TiO₂ maintained a certain reusage that when the catalyst was used at high temperature activation the production rate could still be 44.5%; Both of thermal catalytic reaction and photocatalytic reduction could be carried out, but efficiency of the thermal catalytic reduction was lower. Porous TiO₂ prepared by Gel-Sol could reach the best catalytic effection of 65%, using 250W UV lamp as light source for 12h reaction.Compared with the traditional Fe reduction process, Photocatalytic reduction process was much simple, mild, conservate energy, low cost and also it could reduce almost 2/3 environmental pollution, maintaining a great potential application. The control and transformation of key factors of photocatalytic oxidated degradation and organic synthesis were radiation intensity, solvent, and dissolved oxygen in the reaction system.