831:
2792:
736:. This is more common in TCF bleaching sequences for two reasons: the acidic chlorine or chlorine dioxide stages tend to remove metal ions (metal ions usually being more soluble at lower pH), and TCF stages rely more heavily on oxygen-based bleaching agents, which are more susceptible to the detrimental effects of these metal ions. Chelant washes are usually carried out at or near pH = 7. Lower-pH solutions are more effective at removing redox-active
2802:
715:
touted as good reagent to allow pulp to be bleached without any chlorine-containing chemicals (totally chlorine-free, TCF). The emphasis has changed, and ozone is seen as an adjunct to chlorine dioxide in bleaching sequences not using any elemental chlorine (elemental-chlorine-free, ECF). Over 25 pulp mills worldwide have installed equipment to generate and use ozone.
454: – the pulp would have been exposed to chlorine, extracted (washed) with a sodium hydroxide solution to remove lignin fragmented by the chlorination, treated with sodium hypochlorite, washed with sodium hydroxide again and given a final treatment with hypochlorite. An example of a modern totally chlorine-free (TCF) sequence is
615:). These materials must be removed between bleaching stages to avoid excessive use of bleaching chemicals, since many of these smaller molecules are still susceptible to oxidation. The need to minimize water use in modern pulp mills has driven the development of equipment and techniques for the efficient use of available water.
261:
The brightness gains achieved in bleaching mechanical pulps are temporary, since almost all of the lignin present in the wood is still present in the pulp. Exposure to air and light can produce new chromophores from this residual lignin. This is why newspaper yellows as it ages. Yellowing also occurs
889:
However, there has been disagreement about the comparative environmental effects of ECF and TCF bleaching. Some researchers found that there is no environmental difference between ECF and TCF, while others concluded that among ECF and TCF effluents before and after secondary treatment, TCF effluents
822:
The bleaching of chemical pulps has the potential to cause significant environmental damage, primarily through the release of organic materials into waterways. Pulp mills are almost always located near large bodies of water because they require substantial quantities of water for their processes. An
885:
TCF bleaching, by removing chlorine from the process, reduces chlorinated organic compounds to background levels in pulp-mill effluent. ECF bleaching can substantially reduce but not fully eliminate chlorinated organic compounds, including dioxins, from effluent. While modern ECF plants can achieve
166:
Mechanical pulp retains most of the lignin present in the wood used to make the pulp and thus contain almost as much lignin as they do cellulose and hemicellulose. It would be impractical to remove this much lignin by bleaching, and undesirable since one of the big advantages of mechanical pulp is
714:
is a very powerful oxidizing agent, and the biggest challenge in using it to bleach wood pulp is to get sufficient selectivity so that the desirable cellulose is not degraded. Ozone reacts with the carbonâcarbon double bonds in lignin, including those within aromatic rings. In the 1990s ozone was
881:
production globally, down from over 90% in 1990. 75% of kraft pulp used ECF, with the remaining 5â6% using TCF. Most TCF pulp is produced in Sweden and
Finland for sale in Germany, all markets with a high level of environmental awareness. In 1999, TCF pulp represented 25% of the European market.
601:
Chlorine dioxide is sometimes used in combination with chlorine, but it is used alone in ECF (elemental-chlorine-free) bleaching sequences. It is used at moderately acidic pH (3.5 to 6). The use of chlorine dioxide minimizes the amount of organochlorine compounds produced. Chlorine dioxide (ECF
694:
to delignify chemical pulp requires more vigorous conditions than for brightening mechanical pulp. Both pH and temperature are higher when treating chemical pulp. The chemistry is very similar to that involved in oxygen delignification, in terms of the radical species involved and the products
286:
Chemical pulps, such as those from the kraft process or sulfite pulping, contain much less lignin than mechanical pulps, (<5% compared to approximately 40%). The goal in bleaching chemical pulps is to remove essentially all of the residual lignin, hence the process is often referred to as
167:
the high yield of pulp based on wood used. Therefore, the objective of bleaching mechanical pulp (also referred to as brightening) is to remove only the chromophores (color-causing groups). This is possible because the structures responsible for color are also more susceptible to
610:
All bleaching agents used to delignify chemical pulp, with the exception of sodium dithionite, break lignin down into smaller, oxygen-containing molecules. These breakdown products are generally soluble in water, especially if the pH is greater than 7 (many of the products are
876:
As a result, from the 1990s onwards, the use of elemental chlorine in the delignification process was substantially reduced and replaced with ECF (elemental chlorine free) and TCF (totally chlorine free) bleaching processes. In 2005, elemental chlorine was used in 19â20% of
116:
The table shows how the two systems rate high-brightness papers, but there is no simple way to convert between the two systems because the test methods are so different. The ISO rating is higher and can be over 100. This is because contemporary white paper incorporates
803:
have been used in pulp bleaching to increase the efficiency of other bleaching chemicals. It is believed that xylanase does this by cleaving ligninâxylan bonds to make lignin more accessible to other reagents. It is possible that other enzymes such as those used by
886:
chlorinated organic compounds (AOX) emissions of less than 0.05 kg per tonne of pulp produced, most do not achieve this level of emissions. Within the EU, the average chlorinated organic compound emissions for ECF plants is 0.15 kg per tonne.
662:, which have multiple oxidation states, facilitate many radical reactions and impact oxygen delignification. While the radical reactions are largely responsible for delignification, they are detrimental to cellulose. Oxygen-based radicals, especially
723:
The effect of transition metals such as Mn on some of the bleaching stages has already been mentioned. Sometimes it is beneficial to remove some of these redox-active metal ions from the pulp by washing the pulp with a
557:
is an unstable gas with moderate solubility in water. It is usually generated in an aqueous solution and used immediately because it decomposes and is explosive in higher concentrations. It is produced by reacting
34:, for which whiteness (similar to, but distinct from brightness) is an important characteristic. These processes and chemistry are also applicable to the bleaching of non-wood pulps, such as those made from
53:
is the amount of incident light reflected from paper under specified conditions, usually reported as the percentage of light reflected, so a higher number means a brighter or whiter paper. In the US, the
642:
groups. The production of these phenoxide groups requires that delignification with oxygen be carried out under very basic conditions (pH > 12). The reactions involved are primarily single-electron (
1949:
Tarkpea, Maria; et al. (1999). "Toxicity of conventional, elemental chlorine-free, and totally chlorineâfree kraft-pulp bleaching effluents assessed by shortterm lethal and subleathal bioassays".
1899:
258:
Chelating agents can contribute to brightness gain by sequestering iron ions, for example, as EDTA complexes, which are less colored than the complexes formed between iron and lignin.
247:), also known as sodium hydrosulfite, is the other main reagent used to brighten mechanical pulps. In contrast to hydrogen peroxide, which oxidizes the chromophores, dithionite
703:, Mn(II/IV), catalyze the decomposition of hydrogen peroxide, so some improvement in the efficiency of peroxide bleaching can be achieved if the metal levels are controlled.
1449:
602:
technology) currently is the most important bleaching method worldwide. About 95% of all bleached kraft pulp is made using chlorine dioxide in ECF bleaching sequences.
1380:
Johansson, E.; S. Ljunggren (1991). "The reactivity of lignin model compounds and the influence of metal ions during bleaching with oxygen and hydrogen peroxide".
458:, where the pulp would be treated with oxygen, then ozone, washed with sodium hydroxide, then treated in sequence with alkaline peroxide and sodium dithionite.
855:
121:(FWA). Because the ISO standard only measures a narrow range of blue light, it is not directly comparable to human vision of whiteness or brightness.
186:
is less than that used in bleaching chemical pulps and the temperatures are lower. These conditions allow alkaline peroxide to selectively oxidize
1906:
861:
Dioxins are highly toxic, and health effects on humans include reproductive, developmental, immune and hormonal problems. They are known to be
59:
989:
1822:
1764:
1089:
2702:
1059:
1340:
682:
salts are added to oxygen delignification to help preserve the cellulose chains, but mechanism of this protection has not been confirmed.
1866:
1549:
and DTPA on the characteristics and treatment of TCF (totally chlorine-free) and ECF (elementally chlorine-free) kraft pulping effluents"
1015:
494:, HClO, is the main chlorine species in solution. To avoid excessive cellulose degradation, chlorination is carried out at pH < 1.5.
1245:
823:
increased public awareness of environmental issues from the 1970s and 1980s, as evidenced by the formation of organizations like
1453:
314:
Delignification of chemical pulps is frequently composed of four or more discrete steps, with each step designated by a letter:
2843:
1202:
Fair, G. M.; Morris, J. C.; Chang, S. L.; Weil, I.; Burden, R. P. (1948). "The behavior of chlorine as a water disinfectant".
1739:"Social Movements and Ecological Modernization: The Transformation of Pulp and Paper Manufacturing, Paper: WP00-6-Sonnenfeld"
1682:"Bleaching of Hardwood Kraft Pulp with Manganese Peroxidase from Phanerochaete sordida YK-624 without Addition of MnSO(inf4)"
1272:
695:
produced. Hydrogen peroxide is sometimes used with oxygen in the same bleaching stage, and this give the letter designation
221:
to remove some of these metal ions from the pulp prior to adding peroxide allows the peroxide to be used more efficiently.
1923:
1518:
865:. Over 90% of human exposure is through food, primarily meat, dairy, fish and shellfish, as dioxins accumulate in the
2687:
2682:
1774:
1155:
1131:
965:
1926:. The Alliance for Environmental Technology (International Association) joint research. October 1994. Archived from
2833:
2697:
2692:
130:
While the results are the same, the processes and fundamental chemistry involved in bleaching chemical pulps (like
827:, influenced the pulping industry and governments to address the release of these materials into the environment.
2001:
1738:
817:
2165:
646:) reactions. Oxygen opens rings and cleaves sidechains, giving a complex mixture of small oxygenated molecules.
851:
1900:"Revision of the Ecolabelling Criteria for Tissue Paper: Comments and background to the second draft proposal"
2616:
990:"Brightness of pulp, paper, and paperboard (directional reflectance at 457 nm), Test Method T 452 om-08"
846:
Conventional bleaching using elemental chlorine produces and releases into the environment large amounts of
278:. The bleaching methods are similar for mechanical pulp, in which the goal is to make the fibers brighter.
1661:
Springer, E. L. (December 1997). "Delignification of Wood and Kraft Pulp with
Peroxymonophosphoric Acid".
1411:
1093:
674:, and under the strongly basic conditions used in oxygen delignification, these compounds undergo reverse
2838:
2267:
993:
777:
118:
127:
ranges from 55 to 75 ISO brightness. Writing and printer paper would typically be as bright as 104 ISO.
2563:
2484:
467:
1067:
150:
used to make the pulp. Lignin is the main source of color in pulp due to the presence of a variety of
1475:
Qiu, Z.; Ni, Y.; Yang, S. (2003). "Using DTPA to decrease manganese-induced peroxide decomposition".
793:
479:
2095:
1355:
899:
854:. Dioxins are recognized as a persistent environmental pollutant, regulated internationally by the
142:(like stoneground, thermomechanical or chemo-thermomechanical). Chemical pulps contain very little
2230:
1833:
2677:
2611:
2568:
839:
510:
At pH > 8 the dominant species is hypochlorite, ClO, which is also useful for lignin removal.
304:
2805:
1596:
2510:
2235:
2120:
1873:
1019:
538:
The main objection to the use of chlorine for bleaching pulp is the large amounts of soluble
308:
2621:
1249:
255:, so efficient use of dithionite requires that oxygen exposure be minimized during its use.
2828:
2379:
1693:
1211:
193:
groups responsible for absorbing visible light. The decomposition of hydrogen peroxide is
182:
is the most commonly used bleaching agent for mechanical pulp. The amount of base such as
8:
2714:
2540:
1994:
768:
A variety of less common bleaching agents have been used on chemical pulps. They include
643:
511:
341:
288:
1697:
1382:
Proceedings of the
Seventh International Symposium on Wood and Pulping Chemistry, vol. I
1215:
295:) was initially used to bleach chemical pulps, but was largely replaced in the 1930s by
2374:
2220:
1966:
1797:
1745:. Berkeley, CA: Institute of International Studies (University of California, Berkeley)
1714:
1681:
1604:
IPST Technical Paper Series, Institute of Paper
Science Atlanta, Georgia and Technology
1500:
1431:
1223:
954:
139:
1565:
1540:
1427:
2742:
2287:
2130:
2021:
1832:. Ensis/CSIRO (Australia) joint research (www.csiro.au). 4 March 2005. Archived from
1770:
1719:
1570:
1492:
1227:
1137:
1127:
971:
961:
781:
773:
769:
691:
491:
438:
383:
232:
190:
179:
1970:
1519:"Dow Chem. data presented at 1994 and 1996 International Pulp Bleaching Conferences"
1504:
1435:
924:
663:
2767:
2626:
2464:
2272:
2242:
2035:
1958:
1709:
1701:
1641:
1560:
1484:
1423:
1219:
757:
737:
647:
612:
550:
519:
475:
362:
351:
214:
198:
183:
23:
1705:
1281:
2777:
2661:
2646:
2601:
2520:
2474:
2444:
2384:
2369:
2210:
2150:
2100:
2048:
2043:
905:
830:
559:
226:
135:
1395:
Suss, H. U.; N. F. Nimmerfroh (1993). "Peroxide
Bleaching â Technology Review".
2795:
2752:
2439:
2404:
2180:
2155:
2090:
1987:
1123:
847:
675:
627:
567:
539:
300:
274:
Hydrogen peroxide and sodium dithionite are used to increase the brightness of
2252:
1041:
58:
T 452 or T 525 standards are used. The international community uses
30:
to lighten its color and whiten the pulp. The primary product of wood pulp is
2822:
2641:
2631:
2548:
2434:
2424:
2394:
2359:
2322:
2257:
2225:
2190:
1927:
1574:
1496:
635:
631:
131:
1141:
975:
756:. A negative impact of chelating agents, as DTPA, is their toxicity for the
146:, while mechanical pulps contain most of the lignin that was present in the
2757:
2656:
2573:
2530:
2429:
2339:
2312:
2307:
2302:
2247:
2215:
2195:
2170:
1962:
1897:
1723:
1280:(Thesis). Faculty of Technology University of Oulu, Finland. Archived from
1231:
870:
275:
151:
1488:
1159:
2772:
2737:
2732:
2651:
2414:
2399:
2344:
2334:
2317:
2297:
2282:
2175:
2125:
2025:
1630:"Kraft pulp bleaching using dimethyldioxirane: stability of the oxidants"
427:
187:
2262:
2709:
2636:
2558:
2515:
2489:
2479:
2409:
2389:
2364:
2329:
2292:
2205:
2185:
1181:
878:
866:
862:
824:
50:
1597:"Effect of Xylanase Pretreatment Procedures for Nonchlorine Bleaching"
2747:
2505:
2469:
2449:
2419:
2354:
2349:
2200:
1397:
Workshop on
Emerging Pulping and Chlorine-free Bleaching Technologies
753:
741:
725:
700:
679:
655:
483:
403:
222:
206:
194:
155:
124:
27:
1646:
1629:
2762:
2606:
2596:
2553:
2277:
1628:
Bouchard, J.; Maine, C.; Berry, R. M.; Argyropoulos, D. S. (1996).
1594:
800:
667:
415:
331:
296:
66:
Comparison of the US and ISO systems rating high-brightness papers
1864:
2525:
2070:
2064:
834:
Worldwide pulp production by type of bleaching used: chlorine (Cl
789:
752:), but also remove most of the beneficial metal ions, especially
671:
1679:
1867:"Environmental Comparison of Bleached Kraft Pulp Manufacturing"
749:
659:
639:
623:
466:
Chlorine replaces hydrogen on the aromatic rings of lignin via
372:
292:
263:
252:
210:
143:
35:
1627:
1246:"Trends in World Bleached Chemical Pulp Production: 1990â2005"
1156:"Treecycle Recycled Paper; About Recycling and Recycled Paper"
699:
in bleaching sequences. Redox-active metal ions, particularly
2459:
2454:
2160:
2010:
1595:
Ragauskas, A. J.; K. M. Poll; A. J. Cesternino (April 1993).
1308:
805:
711:
563:
471:
393:
248:
172:
168:
55:
39:
31:
1924:"ECF and TCF: Toxicity An Analysis of Recent Published Data"
902:â inventor of the continuous process for bleaching wood pulp
229:
are also added to improve bleaching with alkaline peroxide.
1680:
Harazono, Koicho; Ryuichiro Kondo; Kokki Sak (March 1996).
745:
733:
729:
651:
303:
compounds into the environment prompted the development of
218:
213:
are of particular importance in pulp bleaching. The use of
202:
147:
1898:
Ad Hoc
Working Group of European Commission (4 May 2006).
1865:
Duke
University; Johnson&Johnson (19 December 1995).
1979:
487:
1412:"Hydrogen peroxide bleaching of mechanical pulp fines"
542:
compounds produced and released into the environment.
138:) are very different from those involved in bleaching
1379:
856:
Stockholm
Convention on Persistent Organic Pollutants
1394:
450:
A bleaching sequence from the 1950s could look like
1201:
1090:"Pulp bleaching chemicals information from PQ Corp"
925:"PaperOnWeb discussion of brightness and whiteness"
808:to degrade lignin may be useful in pulp bleaching.
251:these color-causing groups. Dithionite reacts with
1410:Haugan, Marianne; Gregersen, Ăyvind Weiby (2006).
1310:. Ann Arbor, MI: UMI Out-of-print Books on Demand.
1060:"Matching newsprint qualities to press technology"
953:
1064:The International Journal of Newspaper Technology
2820:
1823:"Frequently Asked Questions on Kraft Pulp Mills"
1766:Effluents from Pulp Mills using Bleaching â PSL1
482:in the lignin sidechains. Chlorine also attacks
154:naturally present in the wood or created in the
1409:
1341:"Oxygen bleaching processes : an overview"
1182:"PaperOnWeb description of bleaching sequences"
811:
1016:"TAPPI comparison of TAPPI and ISO brightness"
1995:
1120:Wood Chemistry: Fundamentals and Applications
269:
161:
1891:
1872:. Environmental Defense Fund. Archived from
1532:
760:in the treatment of kraft pulping effluent.
486:, but this reaction occurs predominantly at
461:
1798:"Dioxins and their effects on human health"
1743:Berkeley Workshop on Environmental Politics
1538:
1450:"Use of Ozone from web page by Air Liquide"
1117:
1042:"Reviewing the concept of paper brightness"
678:, leading to cleavage of cellulose chains.
630:, which is relatively unreactive and needs
281:
2057:
2002:
1988:
1736:
1274:Studies on washing in kraft pulp bleaching
1713:
1645:
1564:
1474:
1339:McDonough, Thomas Joseph (January 1983).
1338:
1270:
763:
634:or very electron-rich substrates such as
1817:
1815:
1660:
1477:Journal of Wood Chemistry and Technology
1468:
1416:Nordic Pulp & Paper Research Journal
951:
829:
605:
318:Delignification steps of chemical pulps
1948:
1942:
1590:
1588:
1586:
1584:
1539:Larisch, B. C.; Duff, S. J. B. (1997).
1305:
2821:
1951:Environmental Toxicology and Chemistry
1858:
1850:"Chlorine Free Products Association".
1686:Applied and Environmental Microbiology
1384:. Beijing, PR China. pp. 180â187.
1334:
1332:
1113:
1111:
947:
945:
943:
941:
480:adds across carbon carbon double bonds
1983:
1812:
1325:(3rd ed.). Atlanta: TAPPI Press.
1320:
1057:
956:Essentials of Pulping and Papermaking
792:and potassium peroxymonosulfate, and
2801:
1843:
1581:
1195:
685:
1916:
1790:
1757:
1329:
1108:
938:
842:(ECF) and total chlorine free (TCF)
545:
45:
13:
1224:10.1002/j.1551-8833.1948.tb15055.x
960:. San Diego: Academic Press, Inc.
670:groups in the cellulose chains to
14:
2855:
1800:. World Health Organization. 2010
1663:Journal of Pulp and Paper Science
1428:10.3183/npprj-2006-21-01-p105-110
952:Biermann, Christopher J. (1993).
650:compounds, particularly those of
2800:
2791:
2790:
299:. Concerns about the release of
16:Chemical process in paper making
1730:
1673:
1654:
1621:
1511:
1442:
1422:(1). chemeng.ntnu.no: 105â110.
1403:
1388:
1373:
1314:
1299:
1264:
1238:
1174:
1158:. treecycle.com. Archived from
818:Environmental issues with paper
718:
1148:
1082:
1051:
1034:
1008:
982:
917:
514:can be purchased or generated
1:
2844:Environmental impact of paper
2617:Environmental impact of paper
1737:Sonnenfeld, David A. (1999).
1706:10.1128/AEM.62.3.913-917.1996
1566:10.1016/S0273-1223(96)00928-6
911:
848:chlorinated organic compounds
1553:Water Science and Technology
1058:Ducey, Michael (June 2004).
1047:. Axiphos GmbH. August 2001.
812:Environmental considerations
443:
432:
420:
408:
397:
387:
376:
366:
355:
345:
335:
119:fluorescent whitening agents
7:
893:
778:potassium peroxymonosulfate
311:(TCF) bleaching processes.
10:
2860:
2564:Surface chemistry of paper
2067:(Zuo Bo/Tso Po/Tso TzÇ-yi)
1348:IPC Technical Paper Series
815:
518:by reacting chlorine with
270:Bleaching of recycled pulp
162:Bleaching mechanical pulps
2786:
2725:
2670:
2582:
2539:
2498:
2143:
2113:
2083:
2034:
2017:
2009:
1271:SillanpÀÀ, Mervi (2005).
794:peroxymonophosphoric acid
626:exists as a ground-state
618:
462:Chlorine and hypochlorite
323:Chemical or process used
2096:Friedrich Gottlob Keller
1204:J. Am. Water Works Assoc
850:, including chlorinated
706:
282:Bleaching chemical pulps
2834:Pulp and paper industry
2612:Elemental chlorine free
2569:Units of paper quantity
1769:. Health Canada. 1991.
1306:Starnes, W. H. (1991).
840:elemental chlorine free
305:elemental chlorine free
2592:Bleaching of wood pulp
1963:10.1002/etc.5620181115
843:
764:Other bleaching agents
490:= 7, where un-ionized
441:(sodium hydrosulfite)
20:Bleaching of wood pulp
2511:Corrugated fiberboard
2268:Electrical insulation
2121:Thomas Francis Carter
1489:10.1081/WCT-120018612
1323:The Bleaching of Pulp
1321:Singh, R. P. (1979).
1248:. AET. Archived from
890:are the least toxic.
833:
784:, which is generated
606:Extraction or washing
468:aromatic substitution
309:totally chlorine free
1830:gunnspulpmill.com.au
1118:E. Sjöström (1993).
414:Enzymes (especially
1839:on 2 December 2007.
1698:1996ApEnM..62..913H
1361:on 20 February 2009
1216:1948JAWWA..40j1051F
666:, HOâą, can oxidize
512:Sodium hypochlorite
342:Sodium hypochlorite
326:Letter designation
319:
289:Sodium hypochlorite
67:
24:chemical processing
2839:Chemical processes
1930:on 4 November 2007
1879:on 1 December 2006
1162:on 28 January 2020
844:
530:â NaOCl + NaCl + H
474:pendant groups to
317:
262:due to the acidic
65:
2814:
2813:
2139:
2138:
2131:Tsien Tsuen-hsuin
2109:
2108:
2079:
2078:
2022:Paper engineering
1957:(11): 2487â2496.
1912:on 6 August 2009.
1070:on 16 August 2007
1022:on 6 October 2007
782:dimethyldioxirane
774:peroxyformic acid
770:peroxyacetic acid
758:activated sludges
738:transition metals
692:hydrogen peroxide
686:Hydrogen peroxide
664:hydroxyl radicals
506:O â H + Cl + HClO
492:hypochlorous acid
448:
447:
439:Sodium dithionite
406:to remove metals
384:hydrogen peroxide
287:delignification.
233:Sodium dithionite
199:transition metals
180:hydrogen peroxide
114:
113:
2851:
2804:
2803:
2794:
2793:
2778:Beverage cartons
2768:Watercolor paper
2627:Hollander beater
2111:
2110:
2081:
2080:
2055:
2054:
2004:
1997:
1990:
1981:
1980:
1975:
1974:
1946:
1940:
1939:
1937:
1935:
1920:
1914:
1913:
1911:
1905:. Archived from
1904:
1895:
1889:
1888:
1886:
1884:
1878:
1871:
1862:
1856:
1855:
1847:
1841:
1840:
1838:
1827:
1819:
1810:
1809:
1807:
1805:
1794:
1788:
1787:
1785:
1783:
1761:
1755:
1754:
1752:
1750:
1734:
1728:
1727:
1717:
1677:
1671:
1670:
1658:
1652:
1651:
1649:
1625:
1619:
1618:
1616:
1614:
1601:
1592:
1579:
1578:
1568:
1536:
1530:
1529:
1527:
1525:
1515:
1509:
1508:
1472:
1466:
1465:
1463:
1461:
1456:on 8 August 2007
1452:. Archived from
1446:
1440:
1439:
1407:
1401:
1400:
1392:
1386:
1385:
1377:
1371:
1370:
1368:
1366:
1360:
1354:. Archived from
1345:
1336:
1327:
1326:
1318:
1312:
1311:
1303:
1297:
1296:
1294:
1292:
1287:on 9 August 2017
1286:
1279:
1268:
1262:
1261:
1259:
1257:
1242:
1236:
1235:
1210:(5): 1051â1061.
1199:
1193:
1192:
1190:
1188:
1178:
1172:
1171:
1169:
1167:
1152:
1146:
1145:
1115:
1106:
1105:
1103:
1101:
1092:. Archived from
1086:
1080:
1079:
1077:
1075:
1066:. Archived from
1055:
1049:
1048:
1046:
1038:
1032:
1031:
1029:
1027:
1018:. Archived from
1012:
1006:
1005:
1003:
1001:
996:on 15 April 2013
992:. Archived from
986:
980:
979:
959:
949:
936:
935:
933:
931:
921:
648:Transition-metal
613:carboxylic acids
551:Chlorine dioxide
546:Chlorine dioxide
520:sodium hydroxide
476:carboxylic acids
363:sodium hydroxide
361:Extraction with
352:Chlorine dioxide
320:
316:
215:chelating agents
184:sodium hydroxide
140:mechanical pulps
68:
64:
46:Paper brightness
2859:
2858:
2854:
2853:
2852:
2850:
2849:
2848:
2819:
2818:
2815:
2810:
2782:
2721:
2666:
2662:Sulfite process
2647:Paper recycling
2602:Conical refiner
2584:
2578:
2535:
2521:Paper chemicals
2494:
2135:
2105:
2101:Charles Fenerty
2075:
2053:
2049:Missal of Silos
2044:Battle of Talas
2030:
2013:
2008:
1978:
1947:
1943:
1933:
1931:
1922:
1921:
1917:
1909:
1902:
1896:
1892:
1882:
1880:
1876:
1869:
1863:
1859:
1849:
1848:
1844:
1836:
1825:
1821:
1820:
1813:
1803:
1801:
1796:
1795:
1791:
1781:
1779:
1777:
1763:
1762:
1758:
1748:
1746:
1735:
1731:
1678:
1674:
1659:
1655:
1647:10.1139/v96-026
1626:
1622:
1612:
1610:
1599:
1593:
1582:
1548:
1544:
1537:
1533:
1523:
1521:
1517:
1516:
1512:
1473:
1469:
1459:
1457:
1448:
1447:
1443:
1408:
1404:
1399:. Raleigh, N.C.
1393:
1389:
1378:
1374:
1364:
1362:
1358:
1343:
1337:
1330:
1319:
1315:
1304:
1300:
1290:
1288:
1284:
1277:
1269:
1265:
1255:
1253:
1252:on 30 July 2017
1244:
1243:
1239:
1200:
1196:
1186:
1184:
1180:
1179:
1175:
1165:
1163:
1154:
1153:
1149:
1134:
1116:
1109:
1099:
1097:
1096:on 2 April 2007
1088:
1087:
1083:
1073:
1071:
1056:
1052:
1044:
1040:
1039:
1035:
1025:
1023:
1014:
1013:
1009:
999:
997:
988:
987:
983:
968:
950:
939:
929:
927:
923:
922:
918:
914:
906:Paper chemicals
896:
837:
820:
814:
766:
726:chelating agent
721:
709:
688:
676:aldol reactions
621:
608:
597:
593:
589:
585:
581:
577:
560:sodium chlorate
556:
548:
533:
529:
505:
501:
464:
284:
272:
246:
242:
238:
227:sodium silicate
164:
77:
72:
48:
17:
12:
11:
5:
2857:
2847:
2846:
2841:
2836:
2831:
2812:
2811:
2809:
2808:
2798:
2787:
2784:
2783:
2781:
2780:
2775:
2770:
2765:
2760:
2755:
2750:
2745:
2740:
2735:
2729:
2727:
2723:
2722:
2720:
2719:
2718:
2717:
2707:
2706:
2705:
2700:
2695:
2690:
2685:
2678:Paper industry
2674:
2672:
2668:
2667:
2665:
2664:
2659:
2654:
2649:
2644:
2639:
2634:
2629:
2624:
2622:Handmade paper
2619:
2614:
2609:
2604:
2599:
2594:
2588:
2586:
2580:
2579:
2577:
2576:
2571:
2566:
2561:
2556:
2551:
2545:
2543:
2541:Specifications
2537:
2536:
2534:
2533:
2528:
2523:
2518:
2513:
2508:
2502:
2500:
2496:
2495:
2493:
2492:
2487:
2482:
2477:
2472:
2467:
2462:
2457:
2452:
2447:
2442:
2437:
2432:
2427:
2422:
2417:
2412:
2407:
2402:
2397:
2392:
2387:
2382:
2380:Plastic-coated
2377:
2372:
2367:
2362:
2357:
2352:
2347:
2342:
2337:
2332:
2327:
2326:
2325:
2315:
2310:
2305:
2300:
2295:
2290:
2285:
2280:
2275:
2270:
2265:
2260:
2255:
2250:
2245:
2240:
2239:
2238:
2228:
2223:
2218:
2213:
2208:
2203:
2198:
2193:
2188:
2183:
2178:
2173:
2168:
2163:
2158:
2153:
2147:
2145:
2141:
2140:
2137:
2136:
2134:
2133:
2128:
2123:
2117:
2115:
2107:
2106:
2104:
2103:
2098:
2093:
2091:Matthias Koops
2087:
2085:
2077:
2076:
2074:
2073:
2068:
2061:
2059:
2052:
2051:
2046:
2040:
2038:
2032:
2031:
2029:
2028:
2018:
2015:
2014:
2007:
2006:
1999:
1992:
1984:
1977:
1976:
1941:
1915:
1890:
1857:
1854:. Spring 1999.
1842:
1811:
1789:
1775:
1756:
1729:
1692:(3): 913â917.
1672:
1669:(12): 582â584.
1653:
1640:(2): 232â237.
1620:
1580:
1546:
1542:
1531:
1510:
1467:
1441:
1402:
1387:
1372:
1328:
1313:
1298:
1263:
1237:
1194:
1173:
1147:
1132:
1124:Academic Press
1107:
1081:
1050:
1033:
1007:
981:
966:
937:
915:
913:
910:
909:
908:
903:
895:
892:
835:
813:
810:
765:
762:
720:
717:
708:
705:
687:
684:
620:
617:
607:
604:
599:
598:
595:
591:
587:
583:
579:
575:
568:sulfur dioxide
554:
547:
544:
540:organochlorine
536:
535:
531:
527:
508:
507:
503:
499:
463:
460:
446:
445:
442:
435:
434:
431:
423:
422:
419:
411:
410:
407:
400:
399:
396:
390:
389:
386:
379:
378:
375:
369:
368:
365:
358:
357:
354:
348:
347:
344:
338:
337:
334:
328:
327:
324:
301:organochlorine
283:
280:
271:
268:
244:
240:
236:
163:
160:
112:
111:
108:
104:
103:
100:
96:
95:
92:
88:
87:
84:
80:
79:
74:
47:
44:
15:
9:
6:
4:
3:
2:
2856:
2845:
2842:
2840:
2837:
2835:
2832:
2830:
2827:
2826:
2824:
2817:
2807:
2799:
2797:
2789:
2788:
2785:
2779:
2776:
2774:
2771:
2769:
2766:
2764:
2761:
2759:
2756:
2754:
2751:
2749:
2746:
2744:
2741:
2739:
2736:
2734:
2731:
2730:
2728:
2724:
2716:
2713:
2712:
2711:
2708:
2704:
2703:United States
2701:
2699:
2696:
2694:
2691:
2689:
2686:
2684:
2681:
2680:
2679:
2676:
2675:
2673:
2669:
2663:
2660:
2658:
2655:
2653:
2650:
2648:
2645:
2643:
2642:Paper machine
2640:
2638:
2635:
2633:
2632:Kraft process
2630:
2628:
2625:
2623:
2620:
2618:
2615:
2613:
2610:
2608:
2605:
2603:
2600:
2598:
2595:
2593:
2590:
2589:
2587:
2581:
2575:
2572:
2570:
2567:
2565:
2562:
2560:
2557:
2555:
2552:
2550:
2547:
2546:
2544:
2542:
2538:
2532:
2529:
2527:
2524:
2522:
2519:
2517:
2514:
2512:
2509:
2507:
2504:
2503:
2501:
2497:
2491:
2488:
2486:
2483:
2481:
2478:
2476:
2473:
2471:
2468:
2466:
2463:
2461:
2458:
2456:
2453:
2451:
2448:
2446:
2443:
2441:
2438:
2436:
2433:
2431:
2428:
2426:
2423:
2421:
2418:
2416:
2413:
2411:
2408:
2406:
2403:
2401:
2398:
2396:
2393:
2391:
2388:
2386:
2383:
2381:
2378:
2376:
2373:
2371:
2368:
2366:
2363:
2361:
2358:
2356:
2353:
2351:
2348:
2346:
2343:
2341:
2338:
2336:
2333:
2331:
2328:
2324:
2321:
2320:
2319:
2316:
2314:
2311:
2309:
2306:
2304:
2301:
2299:
2296:
2294:
2291:
2289:
2286:
2284:
2281:
2279:
2276:
2274:
2271:
2269:
2266:
2264:
2261:
2259:
2256:
2254:
2251:
2249:
2246:
2244:
2241:
2237:
2234:
2233:
2232:
2229:
2227:
2224:
2222:
2219:
2217:
2214:
2212:
2209:
2207:
2204:
2202:
2199:
2197:
2194:
2192:
2189:
2187:
2184:
2182:
2179:
2177:
2174:
2172:
2169:
2167:
2164:
2162:
2159:
2157:
2154:
2152:
2149:
2148:
2146:
2142:
2132:
2129:
2127:
2124:
2122:
2119:
2118:
2116:
2112:
2102:
2099:
2097:
2094:
2092:
2089:
2088:
2086:
2082:
2072:
2069:
2066:
2063:
2062:
2060:
2056:
2050:
2047:
2045:
2042:
2041:
2039:
2037:
2033:
2027:
2023:
2020:
2019:
2016:
2012:
2005:
2000:
1998:
1993:
1991:
1986:
1985:
1982:
1972:
1968:
1964:
1960:
1956:
1952:
1945:
1929:
1925:
1919:
1908:
1901:
1894:
1875:
1868:
1861:
1853:
1846:
1835:
1831:
1824:
1818:
1816:
1799:
1793:
1778:
1776:0-662-18734-2
1772:
1768:
1767:
1760:
1744:
1740:
1733:
1725:
1721:
1716:
1711:
1707:
1703:
1699:
1695:
1691:
1687:
1683:
1676:
1668:
1664:
1657:
1648:
1643:
1639:
1635:
1631:
1624:
1609:
1605:
1598:
1591:
1589:
1587:
1585:
1576:
1572:
1567:
1562:
1558:
1554:
1550:
1535:
1520:
1514:
1506:
1502:
1498:
1494:
1490:
1486:
1482:
1478:
1471:
1455:
1451:
1445:
1437:
1433:
1429:
1425:
1421:
1417:
1413:
1406:
1398:
1391:
1383:
1376:
1357:
1353:
1349:
1342:
1335:
1333:
1324:
1317:
1309:
1302:
1283:
1276:
1275:
1267:
1251:
1247:
1241:
1233:
1229:
1225:
1221:
1217:
1213:
1209:
1205:
1198:
1183:
1177:
1161:
1157:
1151:
1143:
1139:
1135:
1133:0-12-647480-X
1129:
1125:
1121:
1114:
1112:
1095:
1091:
1085:
1069:
1065:
1061:
1054:
1043:
1037:
1021:
1017:
1011:
995:
991:
985:
977:
973:
969:
967:0-12-097360-X
963:
958:
957:
948:
946:
944:
942:
926:
920:
916:
907:
904:
901:
900:Johan Richter
898:
897:
891:
887:
883:
880:
874:
872:
868:
864:
859:
857:
853:
849:
841:
832:
828:
826:
819:
809:
807:
802:
799:Enzymes like
797:
795:
791:
787:
783:
779:
775:
771:
761:
759:
755:
751:
747:
743:
739:
735:
731:
727:
716:
713:
704:
702:
698:
693:
683:
681:
677:
673:
669:
665:
661:
657:
653:
649:
645:
641:
637:
633:
632:free radicals
629:
625:
616:
614:
603:
573:
572:
571:
569:
565:
561:
552:
543:
541:
525:
524:
523:
521:
517:
513:
497:
496:
495:
493:
489:
485:
481:
477:
473:
469:
459:
457:
453:
440:
437:
436:
429:
425:
424:
417:
413:
412:
405:
402:
401:
395:
392:
391:
385:
381:
380:
374:
371:
370:
364:
360:
359:
353:
350:
349:
343:
340:
339:
333:
330:
329:
325:
322:
321:
315:
312:
310:
306:
302:
298:
294:
290:
279:
277:
267:
265:
259:
256:
254:
250:
234:
230:
228:
224:
220:
216:
212:
208:
204:
200:
196:
192:
189:
185:
181:
176:
174:
170:
159:
157:
153:
149:
145:
141:
137:
133:
128:
126:
122:
120:
109:
106:
105:
101:
98:
97:
93:
90:
89:
85:
82:
81:
75:
70:
69:
63:
61:
57:
52:
43:
41:
37:
33:
29:
25:
21:
2816:
2743:Papier-mùché
2738:Paper towels
2657:Soda pulping
2591:
2574:Wet strength
2375:Photographic
2248:Cotton (rag)
2221:Construction
1954:
1950:
1944:
1932:. Retrieved
1928:the original
1918:
1907:the original
1893:
1881:. Retrieved
1874:the original
1860:
1851:
1845:
1834:the original
1829:
1802:. Retrieved
1792:
1782:21 September
1780:. Retrieved
1765:
1759:
1749:20 September
1747:. Retrieved
1742:
1732:
1689:
1685:
1675:
1666:
1662:
1656:
1637:
1634:Can. J. Chem
1633:
1623:
1613:20 September
1611:. Retrieved
1607:
1603:
1556:
1552:
1541:"Effect of H
1534:
1524:19 September
1522:. Retrieved
1513:
1480:
1476:
1470:
1460:19 September
1458:. Retrieved
1454:the original
1444:
1419:
1415:
1405:
1396:
1390:
1381:
1375:
1365:19 September
1363:. Retrieved
1356:the original
1351:
1347:
1322:
1316:
1307:
1301:
1291:19 September
1289:. Retrieved
1282:the original
1273:
1266:
1254:. Retrieved
1250:the original
1240:
1207:
1203:
1197:
1187:17 September
1185:. Retrieved
1176:
1164:. Retrieved
1160:the original
1150:
1119:
1100:17 September
1098:. Retrieved
1094:the original
1084:
1074:15 September
1072:. Retrieved
1068:the original
1063:
1053:
1036:
1026:15 September
1024:. Retrieved
1020:the original
1010:
998:. Retrieved
994:the original
984:
955:
930:17 September
928:. Retrieved
919:
888:
884:
875:
873:of animals.
871:fatty tissue
863:carcinogenic
860:
845:
821:
798:
785:
767:
722:
719:Chelant wash
710:
696:
689:
636:deprotonated
622:
609:
600:
549:
537:
515:
509:
465:
455:
451:
449:
428:peroxy acids
313:
285:
276:deinked pulp
273:
260:
257:
231:
188:non-aromatic
177:
165:
152:chromophores
129:
123:
115:
62:standards.
49:
19:
18:
2829:Papermaking
2773:Paper money
2733:Lined paper
2652:Papermaking
2585:and process
2583:Manufacture
2559:Paper sizes
2288:Greaseproof
2273:GenkĆ yĆshi
2126:Dard Hunter
2058:Originators
2026:Papermaking
1883:18 November
1483:(1): 1â11.
1256:26 February
1000:26 February
566:agent like
526:2 NaOH + Cl
291:(household
78:brightness
73:brightness
2823:Categories
2710:Paper mill
2637:Organosolv
2516:Fiber crop
2506:China clay
2465:Waterproof
2365:Paperboard
2243:Correction
2236:Carbonless
2084:Developers
1934:26 October
1852:CFPA Today
912:References
879:kraft pulp
867:food chain
825:Greenpeace
816:See also:
426:Peracids (
307:(ECF) and
225:salts and
191:conjugated
51:Brightness
2763:Notebooks
2748:Cardboard
2531:Wood pulp
2499:Materials
2475:Wood-free
2450:Wallpaper
2445:Tree-free
2385:Red rosin
2370:Parchment
2355:Onionskin
2350:Newsprint
2211:Cartridge
2206:Cardstock
2201:Cardboard
2151:Acid-free
1575:0273-1223
1497:0277-3813
780:(oxone),
754:magnesium
701:manganese
680:Magnesium
656:manganese
594:+ 2 NaHSO
484:cellulose
404:Chelation
382:Alkaline
223:Magnesium
207:manganese
195:catalyzed
178:Alkaline
173:reduction
169:oxidation
156:pulp mill
125:Newsprint
28:wood pulp
2796:Category
2753:Clothing
2671:Industry
2607:Deinking
2597:Calender
2554:Grammage
2440:Transfer
2405:Security
2278:Glassine
2181:Blotting
2156:Air-laid
2114:Scholars
1971:86517235
1724:16535279
1505:97876479
1436:94131236
1232:18145494
1166:29 March
1142:58509724
976:27173529
894:See also
801:xylanase
728:such as
668:hydroxyl
640:phenolic
564:reducing
472:oxidizes
416:xylanase
332:Chlorine
297:chlorine
2806:Commons
2758:Tissues
2549:Density
2526:Papyrus
2485:Writing
2435:Tracing
2425:Thermal
2400:Scritta
2395:Rolling
2360:Origami
2323:Butcher
2258:Display
2226:Contact
2191:Bristol
2166:Asphalt
2071:Damjing
2065:Cai Lun
2036:History
1804:11 June
1715:1388804
1694:Bibcode
1559:(2â3).
1212:Bibcode
869:in the
852:dioxins
790:acetone
786:in situ
672:ketones
644:radical
638:lignin
628:triplet
590:â 2 ClO
574:2 NaClO
562:with a
516:in situ
249:reduces
136:sulfite
22:is the
2688:Europe
2683:Canada
2430:Tissue
2340:Manila
2313:Korean
2308:Ingres
2303:Inkjet
2216:Coated
2196:Carbon
2171:Banana
1969:
1773:
1722:
1712:
1573:
1503:
1495:
1434:
1230:
1140:
1130:
974:
964:
690:Using
660:copper
624:Oxygen
619:Oxygen
373:Oxygen
293:bleach
264:sizing
253:oxygen
211:copper
201:, and
144:lignin
71:TAPPI
36:bamboo
2698:Japan
2693:India
2460:Wasli
2455:Washi
2415:Stone
2345:Mummy
2335:Lokta
2318:Kraft
2298:India
2283:Graph
2253:CrĂȘpe
2176:Bible
2161:Amate
2144:Types
2011:Paper
1967:S2CID
1910:(PDF)
1903:(PDF)
1877:(PDF)
1870:(PDF)
1837:(PDF)
1826:(PDF)
1600:(PDF)
1501:S2CID
1432:S2CID
1359:(PDF)
1344:(PDF)
1285:(PDF)
1278:(PDF)
1045:(PDF)
806:fungi
788:from
712:Ozone
707:Ozone
553:, ClO
456:OZEPY
452:CEHEH
394:Ozone
217:like
132:kraft
110:â„109
56:TAPPI
40:kenaf
32:paper
2726:Uses
2715:List
2490:Xuan
2480:Wove
2410:Seed
2390:Rice
2330:Laid
2293:Hemp
2231:Copy
2186:Bond
1936:2007
1885:2007
1806:2010
1784:2007
1771:ISBN
1751:2007
1720:PMID
1615:2007
1571:ISSN
1526:2007
1493:ISSN
1462:2007
1367:2007
1293:2007
1258:2016
1228:PMID
1189:2007
1168:2013
1138:OCLC
1128:ISBN
1102:2007
1076:2007
1028:2007
1002:2016
972:OCLC
962:ISBN
932:2007
734:DTPA
730:EDTA
658:and
652:iron
586:+ SO
478:and
433:Paa
219:EDTA
209:and
203:iron
148:wood
102:108
94:104
76:ISO
2470:Wax
2420:Tar
1959:doi
1710:PMC
1702:doi
1642:doi
1608:482
1561:doi
1485:doi
1424:doi
1352:132
1220:doi
838:),
732:or
578:+ H
502:+ H
235:(Na
197:by
171:or
134:or
107:97
99:96
91:92
86:88
83:84
60:ISO
38:or
26:of
2825::
2263:DĂł
2024:/
1965:.
1955:18
1953:.
1828:.
1814:^
1741:.
1718:.
1708:.
1700:.
1690:62
1688:.
1684:.
1667:23
1665:.
1638:74
1636:.
1632:.
1606:.
1602:.
1583:^
1569:.
1557:35
1555:.
1551:.
1499:.
1491:.
1481:23
1479:.
1430:.
1420:21
1418:.
1414:.
1350:.
1346:.
1331:^
1226:.
1218:.
1208:40
1206:.
1136:.
1126:.
1122:.
1110:^
1062:.
970:.
940:^
858:.
796:.
776:,
772:,
750:Cu
748:,
746:Fe
744:,
742:Mn
697:Op
654:,
582:SO
570::
522::
498:Cl
488:pH
470:,
444:Y
430:)
421:X
418:)
409:Q
398:Z
388:P
377:O
367:E
356:D
346:H
336:C
266:.
205:,
175:.
158:.
42:.
2003:e
1996:t
1989:v
1973:.
1961::
1938:.
1887:.
1808:.
1786:.
1753:.
1726:.
1704::
1696::
1650:.
1644::
1617:.
1577:.
1563::
1547:2
1545:O
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1528:.
1507:.
1487::
1464:.
1438:.
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1369:.
1295:.
1260:.
1234:.
1222::
1214::
1191:.
1170:.
1144:.
1104:.
1078:.
1030:.
1004:.
978:.
934:.
836:2
740:(
596:4
592:2
588:2
584:4
580:2
576:3
555:2
534:O
532:2
528:2
504:2
500:2
245:4
243:O
241:2
239:S
237:2
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