[雙語(yǔ)翻譯]--環(huán)境工程印染廢水處理外文翻譯--催化法處理合成染料廢水化學(xué)需氧量及色度的去除（英文）

1、See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/275163673Catalytic treatment of synthetic dyewastewater: COD and color reductionArticle in Journal of Envir

2、onmental Chemical Engineering · September 2013DOI: 10.1016/j.jece.2013.06.008CITATION1READS303 authors, including:Some of the authors of this publication are also working on these related projects:Power-plant CO2 em

3、ission capture using amine based absorption technology View projectMechanochemically synthesized leucite based bioactive glass ceramic composite for dentalveneering View projectPradeep KumarIndian Institute of Technology

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5、j Kumar Mondal on 02 September 2015.The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original documentand are linked to publications on ResearchGate, l

6、etting you access and read them immediately.brand dye was purchased from Alfa Industries, Ahmedabad, India. The dye was dissolved in distilled water to have different concentrations. The chemicals used as catalysts and f

7、or COD calculation were of analytical reagent grade. Cupric sulfate penta hydrate (CuSO4?5H2O) and cuprous oxide (CuO) were procured from S.D. Fine Chemicals Ltd., Mumbai, India, whereas, magnesium sulfate hepta hydrate

8、(MgSO4?7H2O), ferric chloride (FeCl3), calcium chloride (CaCl2), ferrous sulfate hepta hydrate (FeS- O4?7H2O), potassium dichromate (K2Cr2O7), silver sulfate (Ag2SO4), mercuric sulfate (HgSO4), aluminum sulfate [Al2(SO4)

9、3?nH2O], HCl and NaOH all received from Thermo Fisher Scientific India Pvt. Ltd. etc. The physico-chemical properties of catalysts used for experimentation are presented in Table 2.Analytical methodHANNA multi-par

10、ameter photometer (Model HI 83099 COD, Singapore) was used for color test for the synthetic wastewater samples. Color of the samples was read at wavelength of 420 nm in terms platinum-cobalt unit (PCU). For COD routine a

11、nalogous procedure of titrating with ferrous ammonium sulfate was used. Concentration was estimated using the standard calibration curve (absorbance vs. concentration). FTIR spectroscopy of dye and residue was done on FT

12、IR Spectrophotometer (Nicolet 5700 Thermo Electron) and readings were recorded in frequency or wave number ranging from 4000 to 500 cm?1 using KBr pellet.Experimental procedureThe experimental studies at temperatures hig

13、her than ambient temperature were carried out in a 0.5 L three-necked glass reactor (Fig. 1). Wastewater of 100 mg/L concentration was generated, with characterization given in Table 3. Initially, the pH of the wastewate

14、r was adjusted by adding HCl or NaOH solution where 300 ml of synthetic wastewater was fed to the reactor. Catalyst was added as per requirement. Heating mental with magnetic stirrer was used to raise temperature to the

15、desired value and thermometer for temperature monitoring (fitted in one of the necks). The raising of temperature of wastewater from ambient to 60 ? 2 8C took about 5 min (th). A vertical water-cooled condenserwas attach

16、ed to the middle neck of the reactor to prevent any loss ofvapor. The time taken to attain the desired temperature is theheating time, th. Thus, th was taken as zero for further heating.The experimental runs were conduct

17、ed for 90 min at 60 ? 2 8C.While performing time variation experiment the reactor samples(50 ml) were taken at periodic intervals for the measurement of COD,color and pH. The effects of the reaction parameters, such as p

18、H,temperature, time, catalyst mass loading, initial concentration of dyeand effect of different catalysts were studied.Results and discussionEffect of pHConsidering the experiments performed for deriving the effect of pH

19、0 (initial pH) on COD and color reduction of synthetic dye wastewater, initially temperature was taken as 60 ? 2 8C for 90 minand catalyst mass loading of 2 g/L with CuSO4 as catalyst. The pH wasvaried during the experim

20、ents in the range of 2–12. After eachexperiment, a portion of the treated effluent was taken out andfiltered. The clear liquid was separated and its COD as well as colorwas measured. The results are shown in Fig. 2. It s

21、hows a slowincrease in percent COD reduction initially from pH 6 to 10, whichrises at a faster rate between pH 10 and 11. From pH 11 to 12 there hasbeen fall in COD reduction. Color removed was estimated with respectto i

22、nitial color at that particular pH. Catalyst CuSO4 shows activity inprecipitating dye at pH 11 with a maximum percent COD reduction ofabout 73.33% and color reduction of 52.93%. The dyeing process of reactive dyes is usu

23、ally performed at pH 11–12; hence, dye bath run off is rich in alkali [16,17]. But strange behavior of dye’s color toward pH serves a more critical issue, pH over 6.4 is more of red than pink; hence units of color are ra

24、ised. Similar, behavior in which color of dye changes during chemical oxidation has been observed for Reactive Red 2 and Reactive Red 4 [18]. This enhanced color shows the initiation of hydrolysis reaction of dye at this

25、 pH and persistently rises with higher pH in presence of NaOH. Hydrolysis reaction has always been competi- tive reaction for dyeing process in reactive dyes [13]. The final pH after the treatment was also measured and a

26、 decrease in pH wasTable 1Physical properties of Reactive Pink MB dye.Properties DescriptionC.I. name Reactive Red 74Physical state PowderColor PinkOdor OdorlesspH range 4.5–6.5Density 600–800 kg/m3Solubility in w

27、ater >100 g/L (25 8C)Fig. 1. Photograph of catalytic thermolysis process.Table 2Physico-chemical properties of catalysts.Catalysts used Appearance Purity (%) Basis for purity Acidity (pKa) Density (g/cm3) Melti

28、ngpoint (8C)Solubility(g/100 mL)CuSO4?5H2O Blue crystalline powder Above 98.00 Mass percent 3.5–4.5 3.603 150 203.3MgSO4?7H2O White crystalline powder 98.00 Mass percent – 1.68 150 71.0CuO Black to brown p

29、owder 99.70 Mass percent – 6.315 1326 –FeCl3 Purple red by transmitted light 98.60 Mass percent – 2.898 306 92.0CaCl2 White granule 98.49 Mass percent 8–9 2.15 772 74.5FeSO4?7H2O Blue-green crystals 9