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1、1英文文献翻译 11.1英文文献原文（原文题目） 11.2 中文翻译 92. 专业阅读书目 152.1 当代废纸制浆技术 152.2 制浆原理与工程 152.3制浆造纸污染控制 162.4 加工纸与特种纸 162.5 造纸湿布化学 172.6 再生纤维与废纸脱墨技术 172.7制浆造纸工程设计 182.9 造纸化学品的制备和作用机理 192.10造纸原理与工程 19 1 英文文献翻译1.1 Inorganic Reactions in Chlorine Dioxide Bleaching of Softwood Kraft PulpINTRODUCTIONDue to environmenta

2、l concerns, elemental chlorine is being replaced withchlorine dioxide （ClO2） for the bleaching of wood pulps. Chlorine dioxideis a very selective bleaching reagentpresence of carbohydrates, thereby preserving pulp quality. In addition, ClO2generates less chlorinated organics or adsorbable organic ha

3、lides （AOX）compared to chlorine, increasing the attractiveness of chlorine dioxide as ableaching reagent. However, there are issues surrounding the utilization ofchlorine dioxide. Based on oxidation equivalents it is more expensive thanelemental chlorine. Furthermore, the formation of chlorate and c

4、hloritedecrease its oxidation efficiency, further increasing the cost of bleaching.One of the keys to optimizing a chlorine dioxide bleaching stage is tominimize the formation of chlorate and chlorite. In the past, chlorinedioxide bleaching studies on chlorine pre-bleached pulps have shown thatthe o

5、ptimal usage of chemical （minimum chlorate and chlorite residues）requires that the end pH be around 3.8.1 However, this may not be true forchlorine dioxide pre-bleaching because residual kraft lignin componentsmost likely differ from the residual lignin in a chlorine pre-bleached pulp. Ithas been sh

6、own that lignin structure, particularly phenolic lignin content,directly influences the bleachability of wood pulps.2,3 Therefore, prebleachingwith chlorine dioxide may require different reaction conditions tominimize chlorite and chlorate formation. In this article we report the effectof end pH on

7、the formation of inorganic chlorine species during chlorinedioxide pre-bleaching of a softwood kraft pulp.EXPERIMENTALMaterials3,4-Dimethoxyacetophenone, sodium borohydride （NaBH4）, p-dibromobenzene,biphenyl, and all solvents were purchased from Aldrich Chemicals and used asreceived. Chlorine dioxid

8、e was produced by reacting 80% stabilized sodiumchlorite （ACROS） with 1.5 equivalents of potassium persulfate （Fluka） indistilled water at room temperature. The resulting solution was stripped withUHP-nitrogen. Nitrogen gas containing stripped chlorine dioxide was passedthrough a column of sodium ch

9、lorite （Aldrich）, then scrubbed in coldHPLCwater.Methylveratrylalcohol （MVA） was prepared by reacting 3,4-dimethoxyacetophenonewith 2 equivalents of NaBH4. The reaction mixture was refluxedin 3 : 1 MeOH :H2O for 3 h, neutralized with carbon dioxide, and extractedwith 1,2-dichloroethane. Quantitative

10、 conversion of the acetophenone wasobtained. MS m/z （rel. int.） 182（Mt, 59）, 167（87）, 153（47）, 139（100）,124（32）, 108（21）, 93（50）, 77（21）, 65（25）, 51（11）, 43（41）. 1H-NMR d1.48（d,3H）, 3.90（d,6H）, 4.83（q,1H）, 6.84（q,1H）, 6.86（q,1H）, 6.93（d,1H）.Chlorine Dioxide Reactions with PulpThe 27 kappa softwood k

11、raft pulp （12 g OD） was prebleached with chlorinedioxide using a 0.2 kappa factor. The bleaching was carried out at 10% consistencyat 508C for 2 h. The initial pH of the pulp was adjusted using aqueoussodium hydroxide （5 wt%） or sulfuric acid （5 wt%） to achieve a desired finalpH. HPLC grade water （A

12、ldrich） was used as the makeup water. Polyethylenebags fastened with rubber septa were used for bleaching. Samples forinorganic ion analysis were prepared by injecting 20 mL effluent samplesinto a 7 mL vial and evacuating for 45 s, a 1 mL aliquot of HPLC waterwas then added to the sample, followed b

13、y the addition of a sodium fluorideinternal standard. Effluent samples were taken periodically during the 2 hbleach. Ions were analyzed using an ion-exchange column （Dionex AS9/AG9 guard column） with 2.5 mM sodium borate eluent. The eluent flowrate was 1.75 mL/min. Chemical detection was done by sup

14、pressed conductivityusing a Dionex CD20 conductivity detector. Chlorine dioxideconcentrations were determined by iodometric titration. The quantity ofhypochlorous acid in the reaction medium was determined by trapping withaqueous solutions of dimethylsulfoxide （DMSO）. Samples （100 mL） of thereaction

15、 mixture were injected into 0.5 mL of cold aqueous solutions containingexcess DMSO （0.25 M, pH adjusted to 8）. Trapped samples werequenched after 15 s with a saturated sodium thiosulfate solution. Theresulting dimethylsulfone content was determined by GC using cyclohexanolas an internal standard.Chl

16、orine Dioxide Reactions with MVAMVA reactions were run at 25+18C in an oil bath as previously reported.4The pH of the chlorine dioxide reaction was kept constant by using a pHcontrol feedback loop. Reactions were run in a 100 mL, 4-necked flask. AnOmegaTMpH controller （model PHCN-37） was connected t

17、o a Milton-Roymicro-chemical metering pump （model A771-155S）. A sodium hydroxideolution （0.8 M） was delivered to the reaction vessel from a burette viaNalgenew PVC tubing. The alkali addition did not exceed 1% of the totalreaction volume. The reaction mixture was stirred magnetically with aTeflon co

18、ated bar. The pH of the water and chlorine dioxide were adjustedusing aqueous sodium hydroxide （5 wt%） or sulfuric acid （5 wt%） toachieve the desired final pH and mixed for one minute prior to injection ofan aqueous solution of MVA. Samples of the reaction were taken with asyringe through a rubber s

19、eptum. In the kinetic experiments sampling wasdone until all MVA or chlorine dioxide was consumed.Organic compound concentrations were determined by gas chromatography.Twenty mL samples of the reaction mixture were quenched eitherby adding 0.5 mL of 0.4 M ascorbic acid or 0.5 mL of a saturated aqueo

20、ussodium thiosulfate solution. The quenched samples were extracted with0.5 mL of ethyl acetate containing 0.6 mg/L p-dibromobenzene or biphenylas an internal standard. Thereafter, the samples were dried over anhydroussodium sulfate and made up to 2 mL with ethyl acetate prior to GC analysis.GC analy

21、ses were performed on an HP 5890 （splitless injection） instrumentequipped with a flame ionization detector, using He as the carrier gas.Injector and detector temperatures were 2408C and 2808C, respectively. Separationswere achieved on a J&W DB-5 fused silica capillary column（30 m _ 0.32 mm _ 0.25 mm

22、）. Typical temperature programs were from458C to 2508C at a rate of 108C/min with an initial time delay of 1 min,and from 1008C to 2708C at 10208C/min. In quantitative studies, pdibromobenzeneor biphenyl was used as an internal standard and therelative peak areas and corresponding response factors w

23、ere used tocalculate concentrations.All GCMS analyses were conducted using the GC analysis conditions ona HP 5985B GCMS equipped with a DB-5 capillary column. In the EI mode,the electron energy used was 70 eV.1H-NMR spectra were determined on a GE 300 MHz instrument. Sampleswere dissolved in CDCl3.

24、Chemical shifts are given in ppm downfield fromTMS （tetramethylsilane）.RESULTS AND DISCUSSIONA 27 kappa softwood kraft pulp was bleached with chlorine dioxide （ClO2） tovarious end pH values. The quantity of chlorite （ClO22）, chlorate （ClO32）, andchloride （Cl2） were determined as a function of reacti

25、on time and are shownin Figures 1 and 2.During high pH bleaching （pH 11.2）, chlorite formed rapidly. The firstsample point （3 min） for the pH 11.2 reaction shows that approximately70% of the chlorine dioxide had been converted to chlorite. At this pH thechlorite concentration did not change signific

26、antly （Figure 1A）. However, asthe end pH dropped, chlorite degradation began to occur （Figure 1B1D）.The rate of chlorite consumption appeared to increase with a decrease inbleaching pH. As a result, less residual chlorite was measured after 120 minof bleaching with decreasing end pH. By contrast, ch

27、lorate and chlorideBleaching EfficiencyFinal analysis of inorganic compounds in the bleach effluent shows thatbleaching to an end pH of less than 3.4 results in the most efficient usage ofchemicals. As shown in Figure 3 the amount of residual chlorite t chloratedecreases with end pH until about 3.4.

28、 Below an end pH of 3.4, the quantityof residual chlorite t chlorate levels out. This observation is different thanthat reported by Chollet et al.,11 who found that bleaching a chlorine prebleachedpulp （Kappa no. 5） with chlorine dioxide gave the minimumchlorate t chlorite levels at an end pH of bet

29、ween 3 and 4. In addition, themaximum pulp brightness was attained around an end pH of 3.8. InChollets study the quantity of chlorine dioxide lost to chlorate was shownto increase dramatically with decreasing pH below 3. Under acidic conditionschlorate is formed according to Equation （10）. Under our

30、 conditions, theamount of chlorite that is available to participate in this reaction is likelylower than that in Chollets system due to the higher lignin content of ourpulp. The higher lignin content corresponds to a larger amount of phenolicmoieties （the phenolic hydroxy content of a 30 kappa softw

31、ood kraft pulp isapproximately between 20 to 30% of the residual lignin12,13）, resulting ina much lower concentration of chlorite available to participate in Equation（10）.Brightness and permanganate number trends appear to correlate with theamount of residual chlorite t chlorate. Figure 7 shows that decreasing end pHbelow 3.4 did not have a significant effect on the brightness or the permanganatenumber after an extraction stage; however, the organic chlorine levelCONCLUSIONSPre-bleaching a 27 kappa softwood kraf