外文文獻及翻譯---在由臭氧攪拌反應(yīng)器中有機污染物的破壞模型

1、附錄 1 英文文獻Modeling of organic pollutant destruction in a stirred2tank reactor by ozonationCHENGJiang1 , YANG Zhuo2ru1 , CHEN Huan2qin1 , KUO C. H. 2 , ZAPPI E.M. 2Abstract :Destruction of organic contaminants in water by

2、ozonation is a gas2liquid process which involves ozone mass transfer and fast irreversible chemical reactions. Ozonation reactor design and process optimizing require the modeling of the gas2liquid interactions within t

3、he reactor. In this paper a theoretical model combining the fluid dynamic and reaction kinetic parameters is proposed for predicting the destruction rates of organic pollutants in a semi2batch stirred-tank reactor by oz

4、onation. A simple expression for the enhancement factor as our previous work has been applied to evaluate the chemical mass transfer coefficient in ozone absorption. 2 ,42dichlorophenol (2 ,42DCP) and 2 ,62DCP or their

5、 mixture are chosen as the model compounds for simulating , and the predicted DCP concentrations are compared with some measured data. Keywords : dichlorophenol destruction ; ozonation ; stirred2tank reactor ; enhanceme

6、nt factorIntroductionBecause of the high oxidation potential of ozone (O3 ) , ozonation has been regarded as a promising method for drinking and waste water treatment. A wide range of organic pollutants in water can be d

7、egraded by O3 , O3 combined with H2O2 or UVlight , which are known as Advanced Chemical Oxidation Processes (AOPs) . Compared to the traditional treatment technologies , such as activated carbon adsorption or biodegradat

8、ion , chemical oxidation with ozone offers the advantages ofgreater rate and extent of contaminant destruction. Although there are numerous reports (Hoigne , 1983 ; David , 1991) on the ozonation kinetics research regar

9、ding reaction rate constant , stoichiometric ratio and the identification of intermediates , application of these reaction kinetics to yield essential information for successful reactor and process design has not been

10、received sufficient attention ( Yue , 1992) . This may be partly due to the lack of the chemical mass transfer coefficient of ozone in a specific reactor. It is well known that the mass transfer rate of a gaseous solute

11、 in absorption is enhanced by chemical reactions. The extent of this influence is expressed in terms of the enhancement factor , E , which is defined as the ratio of the mass transfer coefficient of the chemical absorp

12、tion to that of physical absorption. In general , it is hard to determine the chemical mass transfer coefficient by experiment especially in absorption processes accompanied by complex reactions while the physical mass

13、 transfer coefficient may easily be obtained experimentally or from semi-empirical approaches. Based on the film theory Kuo (Kuo ,1982) proposed an iteration method for predicting the enhancement factor of mass transfer

14、 by ozone where DA and DB are the diffusivity of ozone and organic B respectively. k is the second order reaction constant , kd is the first order ozone self2decomposition reaction constant. It should be noted that Eq. (

15、2) is valid only if the following condition holds M = Md + M1 [1 - ( E - 1) /Q] > 4.1. 2 Destruction of the mixture of organic pollutants in aqueous solution by ozonationWhen two or m

16、ore contaminants are present initially in the liquid , the absorption of ozone is accompanied by parallel ozonation reactions. If the competition between these reactions is considered to be dependent only on the reaction

17、 constants ,the depletion rate of organic component Bj in the liquid phase can be derived asThe mass balance for ozone A in the gas phase is the same as Eq. (1) .For the enhancement factor in ozone absorption with paral

18、lel ozonation reactions , an approximate expression can also be deduced relating to the surface renewal model as (Cheng , 2000)where Ej represents the supposed enhancement factor in ozone absorption accompanied by a fir

19、st order ozone self2 decomposition reaction and a second order ozonation reaction of a single reactant Bj .2 Simulating and experimental results2 ,42DCP and 2 ,62DCP isomers were chosen as the model compounds for simu

20、latingwhich are the least and most reactive species with ozone in the DCP isomers respectively. Dichlorophenols have been widely used in the production of pesticides , dyes and other industrial chemicals. They are liste