石油煉油廠污水處理畢業(yè)設(shè)計(jì)外文翻譯外文

1、Process modeling and kinetic evaluation of petroleum refinery wastewater treatment in a photocatalytic reactor using TiO2 nanoparticlesF. Shahrezaei a, Yadollah Mansouri b,?, Ali Akbar Lorestani Zinatizadeh c,?, Aazam Ak

2、hbari d,ea Academic Center for Education, Culture 20–200 mg/l phenol; 1–100 mg/l benzene; 0.1–100 mg/l chromeand 0.2–10 mg/l lead; and other pollutants [1]. Phenol and phenolicderivatives in the petroleum refinery efflue

3、nts pose a significantthreat to the environment due to their extreme toxicity, stability,poor biodegradability and ability to remain in the environment forlong periods [2]. They generally are carcinogenic, causing consid

4、er-able damage and threaten the eco-system in water bodies alongwith human health [3–6]. So, there is an urgent need to developefficient and economical methods to remove these pollutants frompetroleum refinery effluent.T

5、he traditional treatments of refinery wastewater are based on thephysicochemical and mechanical methods and further biologicaltreatment in the integrated activated sludge treatment unit. Severalsolutions are proposed in

6、this regard, including the use of coagulants[7], coagulation enhanced by centrifugation [8], adsorption [9], ultrafiltration [10,11], chemical oxidation [3], membranes [12,13] andmicrowave-assisted catalytic wet air oxid

7、ation [14].Unfortunately, the main drawback of these techniques relates tothe disposal of the spent contaminated activated sludge, the controlof the appropriate reaction conditions, low efficiencies and reactionrates and

8、 operation only within a narrow pH range [15,16].In the recent years, substantial attention has been paid towardsthe advanced oxidation processes (AOPs), which are characterizedby the generation of a hydroxyl radical (?O

9、H), can potentially destroya wide range of organic molecules. The ?OH has a high oxidationpotential (estimated to be +2.8 V) relative to other oxidants. Forozone, H2O2, HOCl and chlorine, the oxidation potentials are 2.0

10、7,1.78, 1.49, and 1.36, respectively [17]. Most AOPs use various combi-nations of hydrogen peroxide, ozone and ultraviolet light to generate?OH, and thus are quite energy intensive. One emerging technology,however, utili

11、zes illuminated semiconductors and is commonlyreferred to as the heterogeneous photocatalytic. The heterogeneousphotocatalytic oxidation (HPO) process employing TiO2 and UV lighthas emerged as a promising new route for t

12、he degradation of persis-tent organic pollutants, and produces more biologically degradableand less toxic substances [18,19]. This process is largely dependentPowder Technology 221 (2012) 203–212? Corresponding authors.

13、Tel.: +98 9183431787; fax: +98 8314274559.E-mail addresses: yadollamansouri@yahoo.com (Y. Mansouri),aliazinatiz@yahoo.com, zinatizadeh@razi.ac.ir (A.A.L. Zinatizadeh).0032-5910/$ – see front matter © 2012 Elsevier B

14、.V. All rights reserved.doi:10.1016/j.powtec.2012.01.003Contents lists available at SciVerse ScienceDirectPowder Technologyjournal homepage: www.elsevier.com/locate/powtecand 1 center point) and the remaining 5 involving

15、 the replication ofthe central point to get a good estimate of the experimental error.Repetition experiments were carried out followed by order of runsdesigned by DOE as shown in Table 2.After conducting the experiments,

16、 the coefficients of thepolynomial model were calculated using the following equation,Khuri and Cornell [30].Y ¼ β0 þ βiXi þ βjXj þ βiiXi 2 þ βjjXj 2 þ βijXiXj þ … ð1Þwhere, i

17、 and j are the linear and quadratic coefficients, respectively,and ß is the regression coefficient. Analysis of variance (ANOVA)was used for graphical analyses of the data to obtain the interactionbetween the proces

18、s variables and the responses. The quality of thefit polynomial model was expressed by the coefficient of determinationR2, and its statistical significance was checked by the Fisher's F-test in thesame program. Model

19、 terms were evaluated by the P-value (probability)with 95% confidence level. Three-dimensional plots and their respectivecontour plots were obtained for TCOD removal based on effects of thefour variables (pH, catalyst co

20、ncentration, temperature and reactiontime) at five levels. Furthermore, the optimum region was identifiedbased on the main parameters in the desirability plot.2.6. Photoreactor operationIn the first stage, to run the exp

21、eriments, 1200 ml of a sample,containing a known level of initial organic compounds (TCOD:220 mg/l) and with the appropriate amount of added catalyst wastransferred to the reactor. The solution was then exposed to contin

22、u-ous aerating and circulating. After adjustment of temperature and pH,the UV irradiation was begun. In the second stage, involving modelingby RSM, the photoreactor was operated under the experimentsconditions designed b

23、y Design Expert Software (Table 2). The resultscan be obtained as response surface presentations for visualizationand also as contours to appreciate the effect of system variables onresponse.3. Results and discussion3.1.

24、 Model fitting and statistical analysisExperimental data for TCOD removal treating PRW in a photocata-lyst system with TiO2 nanoparticles are given in Table 2. The relation-ship between the four variables (pH, catalyst c

25、oncentration,temperature and reaction time) and TCOD removal efficiency wasanalyzed using response surface methodology (RSM). The predictedvalues were obtained from model fitting technique using the designV-1........ ...

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