Study On Photocatalysis Degradation Of Several Refractory Organic Pollutants

The technique of photocatalysis oxidation is a new kind of water treatment process with great potential application especially in the organic substances degradation for its outstanding effect . This paper mainly investigated the photocatalytic degradation of high concentration dyeing wastewater, 2,4-dicholorophenal simulated wastewater and printingbill wastewater, respectively. The functional mechanism, catalytic activity and the main problems including TiO2 crystalloid, pH value of solution, H2O2, initial organic concentration, electron receptor, metal ion, amount of catalyst and the dispersion situation in the liquid are discussed in details.The photocatalytic reactor which is designed by author and manufactured by shanghai organic chemistry research institute is used in this experience. To examine the decoloring efficiency of suspension system, photocatalytic decolorization of a acid dye(Acid Blue 62) was studied as an example . the effect of TiO2 quantity, electron receptor, pH etc and the mechanism were studied in the condition of high concentration dye solution . Among the systems of TiO2/UV/ H2O2, TiO2/UV, UV/ H2O2, TiO2/UV/H2O2 presents the best one to degrade the AB dyeing wastewater. It is found that the decolourization effect only with TiO2 within short time have not been improved while improved up to 70% with the H2O2 input. The lower of the initial AB concentration, the higher the decoloring rate removal efficiency. The dyeing assistants has negative influence on the dispersity of TiO2 particles and the formation of HO, resulting in low decoloring efficiency.In the process of the photocatalytic degradation of printingbill , the dosage and characteristic of TiO2, H2O2, Fe2+, Fenton reagent and pH are argued, the photodegradation can be improved in the condition of acidin suspension system. The degradation efficiency of pritingbill wastewater by photocatalytic or Fenton reagent is no better than the combination of Fenton reagent and UV illumination.Among the systems of UV/H2O2, H2O2/Fe2+ UV/H2O2/Fe2+/H+and UV/ H2O2/ Fe2+/Fe3+, UV/ H2O2/ Fe2+/H+ presents the best one to degrade the pritingbill wastewater . The decoloring rate and CODcr removal efficiency were 75% and 50% respectively.The process of the photocatalytic degradation of 2,4-dicholorophenal by TiO2 was studied under high pressure mercury lamp. In order to study the photodegradation dynamics of 2,4-dicholorophenal in water, firstly, to establish the analysis methods of determination of 2,4-dicholorophenal , this part investigates the determination of 2,4-dicholorophenal by ultraviolet spectrophotometry and establishes the analysis methods of determination of 2,4-dicholorophenal by ultraviolet spectrophotometry and ascertain this method to determine the 2,4-dicholorophenal, secondly, to determine the mechanism of 2,4-dicholorophenal simulated water under different conditions, the relationship between the degradation rate and the initial organic concentration was found to follow Langmuir-Hinshelwood model and the result suggested that photocatalytic of 2,4-dicholorophenal was zero-order kinetics. The influences of various parameters were studied.Finally , the recent development of photocatalytic reactor is presented and the trend is also predicted.Mu Feng (Environmental Science and Engineering ) Supervised by: Prof. ZhuangHuisheng...