Biotechnology for Pulp and Paper Processing

Pratima Bajpai

Biotechnology for Pulp and Paper Processing

Pratima BajpaiThapar Research and Development Center ColonyPatiala, Indiapratima.rcdp@gmail.com

ISBN 978-1-4614-1408-7 e-ISBN 978-1-4614-1409-4DOI 10.1007/978-1-4614-1409-4Springer New York Dordrecht Heidelberg London

Library of Congress Control Number: 2011941212

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v

Preface

The pulp and paper (P&P) industry is traditionally known to be a large contributor to environmental pollution due to its large consumption of energy and chemicals. Biotechnological methods, however, offer potential opportunities for changing the industry toward more environmentally friendly and effi cient operations compared to the conventional methods. The importance of biotechnology lies in its potential for more specifi c reactions, less environmentally deleterious processes, energy savings, and capacity to be used in place of nonbiological processes. Increased pulp yield, improved fi ber properties, enhanced paper recycling, reduced processing and envi-ronmental problems, and energy effi ciency are all consequences of biotechnological processes in the pulp and paper industry. The number of possible applications of biotechnology in pulp and paper manufacture has grown steadily during the past 3 decades. Many applications have approached or are approaching commercial real-ity. Applications that have been successfully transferred to commercial use include xylanases for bleach boosting; cellulases for improved drainage; lipases for pitch removal; cellulase–hemicellulase mixture for deinking and fi ber modifi cation; esterases for stickies control; and levan hydrolase, proteases, cellulases, amylases, etc. for slime removal. “Biotechnology for Pulp and Paper Processing” gives updated information on various biotechnological processes useful in the pulp and paper industry; these processes could help in reducing environmental pollution problems, in addition to other benefi ts. Various chapters deal with latest developments in the areas like Tree improvement, Raw material preparation, Pulping, Bleaching, Deinking, Fiber modifi cation, Slime control, Stickies control, Production of dis-solving grade pulp, Shive removal, Vessel picking, Degradation of pollutants, Retting of fl ax, Treatment of exhaust gasses for removal of odorous emissions, and Biosolids management. Biotechnology for Pulp and Paper Processing also includes a chapter on Forest Products Biorefi nery. Biorefi neries actually can help pulp mills use by-products and residual products of the papermaking process to create addi-tional high-value revenue streams. The major benefi ts, limitations, and future pros-pects of these processes have also been discussed.

Patiala, India Pratima Bajpai

vii

Contents

1 Introduction ............................................................................................ 11.1 Introduction ..................................................................................... 1References ................................................................................................ 4

2 Brief Description of the Pulp and Paper Making Process .................. 72.1 Introduction ..................................................................................... 72.2 Pulp and Paper Making Process ...................................................... 8

2.2.1 Pulp Making Process ........................................................... 82.2.2 Stock Preparation and Paper Making Process..................... 10

References ................................................................................................ 13

3 Tree Improvement .................................................................................. 153.1 Introduction ..................................................................................... 15

3.1.1 Forest Trees in the Age of Modern Genetics ...................... 16References ................................................................................................ 21

4 Biodebarking .......................................................................................... 234.1 Introduction ..................................................................................... 234.2 Enzymes Used for Debarking ......................................................... 264.3 Application of Enzymes for Debarking .......................................... 264.4 Advantages of Biodebarking ........................................................... 294.5 Limitations and Future Prospects .................................................... 29References ................................................................................................ 30

5 Biodepitching .......................................................................................... 335.1 Introduction ..................................................................................... 335.2 Environmental Impact of Lipophilic Extractives ............................ 345.3 Methods for Pitch control ............................................................... 36

5.3.1 Conventional Treatment ...................................................... 365.3.2 Biological Treatment ........................................................... 36

5.4 Advantages, Limitations, and Future Prospects .............................. 49References ................................................................................................ 50

viii Contents

6 Bioretting ................................................................................................ 576.1 Introduction ..................................................................................... 576.2 Methods for Retting ........................................................................ 586.3 Enzymes Used in Flax-Retting ....................................................... 596.4 Application of Enzymes in Flax-Retting ........................................ 596.5 Effect of Enzyme-Retting on Fiber Yield and Properties ............... 646.6 Effect of Enzyme-Retting on Effl uent Properties ........................... 64References ................................................................................................ 65

7 Biopulping ............................................................................................... 677.1 Introduction ..................................................................................... 677.2 Pulping Processes ............................................................................ 68

7.2.1 Mechanical Pulping ............................................................ 687.2.2 Semichemical Pulping ........................................................ 697.2.3 Chemical Pulping ................................................................ 70

7.3 Biomechanical Pulping ................................................................... 717.4 Biochemical Pulping ....................................................................... 797.5 Biopulping with Laccase Mediator System .................................... 847.6 Mechanism of Biopulping ............................................................... 847.7 Advantages of Biopulping .............................................................. 867.8 Limitations and Future Prospects .................................................... 87References ................................................................................................ 87

8 Biobleaching ........................................................................................... 938.1 Introduction ..................................................................................... 938.2 Xylanase Enzymes .......................................................................... 93

8.2.1 Production and Properties of Xylanases ............................. 948.2.2 Performance of Xylanases in Bleaching ............................. 988.2.3 Effect of Xylanases on Pulp and Effl uent Quality .............. 1048.2.4 Mechanism of Bleaching .................................................... 1048.2.5 Conclusion and Future Prospects ........................................ 105

8.3 Lignin-Oxidizing Enzymes ............................................................. 1068.3.1 Performance of Lignin-Oxidizing

Enzymes in Bleaching ......................................................... 1068.3.2 Effect of Lignin-Oxidizing Enzymes on Pulp

and Effl uent Quality ............................................................ 1168.3.3 Mechanism of Bleaching .................................................... 1178.3.4 Advantages, Limitations, and Future Prospects .................. 121

8.4 White-Rot Fungi ............................................................................. 1228.4.1 Performance of White-Rot Fungi in Bleaching .................. 1228.4.2 Effect of White-Rot Fungi on Pulp

and Effl uent Quality ............................................................ 1288.4.3 Advantages, Limitations, and Future Prospects .................. 128

References ................................................................................................ 129

ixContents

9 Biodeinking ............................................................................................. 139 9.1 Introduction ................................................................................... 139 9.2 Enzymes Used in Deinking ........................................................... 140 9.3 Mechanisms of Enzyme Deinking ................................................ 140 9.4 Application of Enzymes in Deinking ............................................ 141 9.5 Effect of Enzyme on Fiber and Paper Quality .............................. 152 9.6 Effect of Enzyme on Pulp Yield ................................................... 152 9.7 Effect of Enzyme on Effl uent Characteristics ............................... 153 9.8 Benefi ts and Limitations ............................................................... 154 9.9 Conclusions ................................................................................... 155References ................................................................................................ 156

10 Fiber Modifi cation ................................................................................. 15910.1 Introduction ................................................................................... 15910.2 Enzymes Promoting Beatability/Refi nability ............................... 160

10.2.1 Enzyme Actions .............................................................. 16610.2.2 Effects of Enzyme ........................................................... 16710.2.3 Potential Benefi ts of Enzymatic Treatment

Before Refi ning ............................................................... 16810.3 Enzymes Improving Drainage ...................................................... 168

10.3.1 Enzyme Action ................................................................ 17510.3.2 Benefi ts of Improving Drainage ...................................... 176

10.4 Enzymes for Vessel-Picking Problems ......................................... 17610.5 Conclusions ................................................................................... 180References ................................................................................................ 181

11 Removal of Shives .................................................................................. 18511.1 Introduction ................................................................................... 18511.2 Application of Enzymes for Shive Removal ................................. 18711.3 Mechanism of Shive Removal with Xylanase Enzymes ............... 18911.4 Benefi ts with Enzymes .................................................................. 19011.5 Conclusions ................................................................................... 191References ................................................................................................ 191

12 Production of Dissolving-Grade Pulp .................................................. 19312.1 Introduction ................................................................................... 19312.2 Enzymes Used in the Production of Dissolving Pulp ................... 19512.3 Application of Enzymes in Production of Dissolving Pulp .......... 19612.4 Conclusions ................................................................................... 206References ................................................................................................ 207

13 Biological Treatment of Pulp and Paper Mill Effl uents ..................... 21113.1 Introduction ................................................................................... 21113.2 Bleaching and Environmental Impact ........................................... 21213.3 Biotechnological Methods for Treatment of Pulp

and Paper Mill Effl uents ............................................................... 21613.3.1 Enzymatic Treatment ...................................................... 21613.3.2 Bacterial Treatment ......................................................... 219

x Contents

13.3.3 Fungal Treatment ............................................................ 23413.3.4 Ligninolytic Enzymes and Their Role

in Decolorization of Bleaching Effl uents ........................ 25013.4 Conclusions and Future Perspectives ............................................ 251References ................................................................................................ 252

14 Slime Control .......................................................................................... 26314.1 Introduction ................................................................................... 26314.2 Slime Problems in the Mills .......................................................... 26414.3 Microorganisms Within the Slime

and Contamination Sources .......................................................... 26814.4 Sites Chosen by the Microorganisms in the Paper Mill ................ 272

14.4.1 Formation of Slime ......................................................... 27314.4.2 Blocking of the Felts ....................................................... 27314.4.3 Degradation of the Felt ................................................... 27314.4.4 Fermentation of Rosins ................................................... 27414.4.5 Stains in the Pulp ............................................................ 27414.4.6 Cellulolytic Action .......................................................... 27414.4.7 Mold ................................................................................ 27514.4.8 Musty Odors .................................................................... 275

14.5 Methods for Detection of Slime .................................................... 27514.5.1 Slime Collection Boards ................................................. 27514.5.2 Identifi cation of the Contaminated Points ....................... 27614.5.3 Standard Plate Count Method ......................................... 27614.5.4 Dip Sticks ........................................................................ 27614.5.5 Luminescence ................................................................. 27614.5.6 Bio-Lert Method ............................................................. 27714.5.7 Slime Monitor ................................................................. 278

14.6 Biofi lm Formation in Paper Systems ............................................ 27814.7 Control of Slime ............................................................................ 281

14.7.1 Traditional Methods ........................................................ 28114.7.2 Use of Enzymes for Control of Slime ............................. 28814.7.3 Biological Equilibrium.................................................... 29114.7.4 Biodispersants ................................................................. 29214.7.5 Use of Competing Microorganisms ................................ 29514.7.6 Biofi lm Inhibitors ............................................................ 29614.7.7 Use of Bacteriophages .................................................... 296

References ................................................................................................ 298

15 Stickies Control ...................................................................................... 30715.1 Introduction ................................................................................... 30715.2 Problems Caused by Stickies ........................................................ 30815.3 Control of Stickies ........................................................................ 309

15.3.1 Enzyme Approach ........................................................... 30915.4 Conclusion .................................................................................... 314References ................................................................................................ 314

xiContents

16 Enzymatic Modifi cation of Starch for Surface Sizing ........................ 31716.1 Introduction ................................................................................... 31716.2 Enzymes Used for Starch Conversion ........................................... 31816.3 Starches Used for Surface Sizing .................................................. 31916.4 Process for Enzymatic Modifi cation of Starch ............................. 32116.5 Benefi ts and Limitations of Enzymatically

Modifi ed Starches ......................................................................... 324References ................................................................................................ 325

17 Biofi ltration of Odorous Gases ............................................................. 32717.1 Introduction ................................................................................... 32717.2 Emissions from Pulping ................................................................ 328

17.2.1 Kraft Pulping ................................................................... 32817.2.2 Emissions from Neutral Sulfi te Semichemical

(NSSC) Pulping .............................................................. 33017.2.3 Emissions from Sulfi te Pulping ...................................... 330

17.3 Methods for the Elimination of Odorous Compounds .................. 33117.3.1 Biofi ltration Technology ................................................. 33117.3.2 Microorganisms in Biofi lter ............................................ 33317.3.3 Packing Materials for Biofi lters ...................................... 33517.3.4 Mechanisms in Biofi lter Operation ................................. 33617.3.5 Development of Biofi ltration Technology ...................... 33717.3.6 Present Status .................................................................. 34117.3.7 Parameters Affecting the Performance of Biofi lter ......... 34217.3.8 Advantages, Limitations and Future Prospects ............... 344

References ................................................................................................ 346

18 Management/Utilization of Wastewater Treatment Sludges.............. 34918.1 Introduction ................................................................................... 34918.2 Dewatering of Sludge .................................................................... 35018.3 Methods of Disposal ..................................................................... 355

18.3.1 Landfi ll Application ........................................................ 35518.3.2 Incineration ..................................................................... 35818.3.3 Land Application (Composting) ..................................... 36018.3.4 Recovery of Raw Materials ............................................. 36318.3.5 Production of Ethanol and Animal Feed ......................... 36418.3.6 Pelletization of Sludge .................................................... 36518.3.7 Manufacture of Building and Ceramic Materials

and Lightweight Aggregate ............................................. 36618.3.8 Landfi ll Cover Barrier ..................................................... 36718.3.9 Other Uses ....................................................................... 368

References ................................................................................................ 370

xii Contents

19 Integrated Forest Biorefi nery ................................................................ 37519.1 Introduction ................................................................................... 37519.2 Forest Biorefi nery Options ............................................................ 377

19.2.1 Hemicellulose Extraction Prior to Pulping ..................... 37919.2.2 Black Liquor Gasifi cation ............................................... 38419.2.3 Removal of Lignin from Black Liquor ........................... 39219.2.4 Other Products (Tall Oil, Methanol, etc.) ........................ 396

19.3 Environmental Impacts of Forest Biorefi neries ............................ 397References ................................................................................................ 397

Index ................................................................................................................ 403

xiii

List of Figures

Fig. 4.1 Cross-sectional line drawing of wood ........................................... 24

Fig. 5.1 Hydrolysis of pitch by lipase ......................................................... 43 Fig. 5.2 Effect of Laccase treatment on removal of extractives

from mechanical pulp, based on Paice (2005) ............................... 47

Fig. 7.1 Biopulping process can be fi tted into an existing mill’s wood handling system ......................................................... 75

Fig. 8.1 Typical xylanase and acidifi cation sites (based on Bajpai 2004) .................................................................. 101

Fig. 8.2 Possible mechanism of laccase and mediator actionon lignin (based on Call and Mücke 1995a, b, 1997) .................... 110

Fig. 8.3 Oxidative pathway for catalytic action of laccase on lignin (based on Bajpai 1997b) ................................................. 119

Fig. 8.4 Oxidative pathway for catalytic action of manganese peroxidase on lignin (based on Bajpai 1997b) .............................. 120

Fig. 8.5 Model of a cross-section of a small portion of secondary wall of wood fi ber (based on Jurasek et al. 1994) ........................................................................ 120

Fig. 8.6 Model of a cross-section area of kraft fi ber shown in comparison with some enzyme molecules (based on Jurasek et al. 1994; Paice 2005) .................................... 121

Fig. 9.1 Schematic diagram showing mechanism of Cellulase action on fi ber. Mohammed (2010); Reproduced with permission ............................................................................. 141

Fig. 9.2 Schematic diagram showing mechanism of Amylase action on fi ber. Mohammed (2010); Reproduced with permission ............................................................................. 141

Fig. 9.3 Effect of enzyme on brightness. Mohammed (2010); Reproduced with permission ......................................................... 144

xiv List of Figures

Fig. 9.4 Effect of enzyme on residual ink count. Mohammed (2010); Reproduced with permission ......................................................... 145

Fig. 9.5 Effect of enzyme on chemical consumption. Mohammed (2010); Reproduced with permission ........................ 145

Fig. 9.6 Enzymatic deinking (a) furnish composition of tissue with ISO brightness 61 (b) furnish composition of tissue with ISO brightness 77 (c) net cost change in total raw materials (furnish plus all chemistry) by using enzymatic deinking. Tausche (2005a, b); Reproduced with permission ......................................................... 149

Fig. 9.7 Enzymatic deinking: Tappi dirt reductions. Tausche (2005a, b); Reproduced with permission ......................... 150

Fig. 9.8 Enzymatic deinking: Brightness gains. Tausche (2005a, b); Reproduced with permission ......................... 150

Fig. 9.9 Enzymatic deinking: (a) mill fi ber yield (b) indexed sludge generation. Tausche (2005a, b); Reproduced with permission ......................................................... 150

Fig. 9.10 SEM of toner particle detachment (a) conventional deinking (b) enzymatic deinking. Tausche (2005a, b); Reproduced with permission ......................................................... 151

Fig. 10.1 Biorefi ning of hardwood fi bers. Michalopoulos et al. (2005); Reproduced with permission .................................... 166

Fig. 10.2 Biorefi ning of softwood fi bers. Michalopoulos et al. (2005); Reproduced with permission .................................... 167

Fig. 10.3 Effect of enzyme dose on machine speed using OCC and MW pulps to produce 200-gsm liners at a North American mill. Based on Shaikh and Luo (2009) ............... 174

Fig. 10.4 Untreated vessel pick. Covarrubias (2009, 2010); Reproduced with permission ......................................................... 177

Fig. 10.5 Treated vessel pick. Covarrubias (2009, 2010); Reproduced with permission ......................................................... 178

Fig. 10.6 Effect of enzyme on IGT. Gill (2008); Reproduced with permission ............................................................................. 179

Fig. 10.7 Effect of enzyme on internal bond. Gill (2008); Reproduced with permission ......................................................... 179

Fig. 10.8 Effect of enzyme on long fi ber and internal bond. Gill (2008); Reproduced with permission ..................................... 180

Fig. 10.9 Effect of enzyme on porosity. Gill (2008); Reproduced with permission ......................................................... 180

Fig. 12.1 Types of cellulases: (a) Endoglucanases without cellulose-binding domain (b) endoglucanases with cellulose-binding domain; (c, d) cellobiohydrolases (e) glucosidases. Based on Köpcke (2010b) .................................. 204

xvList of Figures

Fig. 12.2 Mode of action of various components of cellulose. Based on Wood and McCrae (1979) .............................................. 204

Fig. 13.1 The character of AOX in the effl uent from conventionally pulped and bleached kraft pulp. Based on Bajpai and Bajpai (1996) and Gergov et al. (1988) ....................... 213

Fig. 13.2 Specifi c compounds discharged from bleached pulp mills. Based on Gavrilescu (2006); Liebergott et al. (1990) .................................................................. 215

Fig. 13.3 Most toxic isomers of polychlorinated dioxins and furans. Based on Gavrilescu (2006) and Rappe and Wagman (1995) ....................................................................... 216

Fig. 13.4 The principle of combined fungal and enzyme treatment system. Based on Zhang (2001) .................................... 246

Fig. 14.1 Composition of EPS (extracellular polysaccharides) from paper machines (Grant 1998; reproduced with permission) ............................................................................ 265

Fig. 15.1 Results of enzyme treatment on stickies (no treatment on the left and after Optimyze treatment on the right) (Reproduced with permission from Patrick (2004)) ...................... 311

Fig. 15.2 Electron photomicrograph of the surfaces of a stickies particle before enzyme treatment (left) and after treatment (right) Patrick (2004); Reproduced with permission ..................... 311

Fig. 16.1 Batch starch conversion system (Based on Tolan (2002)) ............. 323Fig. 16.2 Continuous starch conversion system

(Based on Tolan (2002)) ................................................................ 323

Fig. 19.1 Current pulp mill; reproduced from Thorp et al. (2008) with permission ............................................................................. 376

Fig. 19.2 Future mill; reproduced from Thorp et al. (2008) with permission ............................................................................. 377

Fig. 19.3 Possible products from a pulp mill biorefi nery; reproduced from Axegård (2005) with permission ....................... 377

Fig. 19.4 Biorefi nery concept; reproduced from the National Renewable Energy Laboratory Biomass Research website: http://www.nrel.gov/biomass/biorefi nery.html with permission. Accessed April 20, 2011 .................................... 378

Fig. 19.5 Integrated gasifi cation and combined cycle (IGCC); based on Sricharoenchaikul (2001) ............................................... 384

Fig. 19.6 MTCI steam reformer; based on Whitty and Baxter (2001) .......................................................................... 388

Fig. 19.7 The CHEMREC DP-1 plant. Source: www.chemrec.se/admin/UploadFile.aspx?path=/UserUploadFiles/2005%20DP-1%20brochure.pdf (reproduced with permission) ........................................................ 389

xvi List of Figures

Fig. 19.8 The two-stage washing/dewatering process, LignoBoost, for washing lignin precipitated from black liquor; reproduced from Axegård (2007b) with permission ..................... 393

Fig. 19.9 Integration opportunities between LignoBoost and gasifi cation of forestry residues proposed by STFI-Packforsk and VTT; reproduced from Axegård (2007b) with permission ................................................. 395

xvii

List of Tables

Table 1.1 Biotechnology for the pulp and paper industry in different stages of development ............................................ 3

Table 4.1 Effect of pretreatment with polygalacturonase enzyme on energy consumption during debarking of spruce .................................................................. 26

Table 4.2 Effect of enzyme treatment on energy consumption during debarking of spruce ....................................................... 27

Table 4.3 Effect of enzyme treatment time on energy consumption during debarking of spruce ....................................................... 28

Table 4.4 Stability of enzyme in the debarking water .............................. 28 Table 4.5 Effects of various pectinases on hydrolysis

of isolated cambium.................................................................. 29

Table 5.1 Extractive degradation by sap-stain fungi on nonsterile southern yellow pine ........................................... 37

Table 5.2 Extractive content of sterile lodgepole pine and aspen treated with sap-stain fungi....................................................... 38

Table 5.3 Use of a depitching organism in a TMP mill ............................ 39 Table 5.4 Resin content (% of dry wood) of loblolly pine chips

treated with C. subvemispora or O. piliferum after 1–4 weeks incubation ............................................................... 40

Table 5.5 Resin content of spruce chips treated with various fungi after 2 weeks incubation and kappa numbers after sulfi te cooking .................................................................. 40

Table 5.6 Extractive content of sterile southern yellow pine treated with various basidiomycetes ......................................... 41

Table 5.7 DCM extractive content of nonsterile southern yellow pine treated with various molds ................................................ 42

Table 5.8 Effect of lipase treatment on pitch deposition .......................... 44 Table 5.9 Effect of lipase concentration on hydrolysis

of trigycerides ........................................................................... 44

xviii List of Tables

Table 6.1 Effect of enzymes on fl ax-retting ............................................. 60 Table 6.2 Effects of enzyme-, chemical-, and water-retting

on fi ber yield and fi ber properties ............................................. 60 Table 6.3 Properties of fi bers from fl ax retted

with different enzymes ............................................................. 63 Table 6.4 Effect of enzyme-retting on effl uent properties ........................ 64

Table 7.1 Energy requirement in the production of mechanical pulps .................................................................. 68

Table 7.2 Energy requirement for chemimechanical pulp (CMP) and biochemimechanical pulp (BCMP) from bagasse ............................................................................. 72

Table 7.3 Energy savings from biomechanical pulping of loblolly pine chips with different white-rot fungi (4-week incubation) .................................................................. 73

Table 7.4 Tensile indexes of biomechanical pulps ................................... 76 Table 7.5 Properties of mill-refi ned pulps prepared

from Eucalyptus wood chips treated with Phanerochaete chrysosporium ......................................... 76

Table 7.6 Characteristics of bleached CTMP wastewater ........................ 77 Table 7.7 Composition of resin acids in bleached

CTMP wastewater .................................................................... 77 Table 7.8 BOD, COD, and toxicity of nonsterile aspen chips

after treatment with C. subvermispora ..................................... 78 Table 7.9 Effect of fungal treatment on resin content

(% of dry wood) of loblolly pine and spruce chips .................. 79 Table 7.10 Biokraft pulping of eucalyptus with C. subvermispora

at reduced active alkali charge .................................................. 80 Table 7.11 Soda pulping of wheat straw with C. subvermispora

strains 1 and 2 at reduced alkali charges .................................. 81 Table 7.12 Effect of cooking time on soda pulping

of C. subvermispora-treated wheat straw ................................. 82 Table 7.13 Properties of kraft pulps prepared from

Eucalyptus nitens and Eucalyptus globulus .............................. 83

Table 8.1 Plant-scale trial results with xylanase ....................................... 99 Table 8.2 Summary of results from the pilot plant trial

with laccase-mediator system (LMS) ....................................... 110 Table 8.3 Conceptual difference between the xylanase

and laccase/mediator treatment ................................................ 111 Table 8.4 Bleaching conditions and optical properties

of conventionally bleached and fungal bleached hardwood kraft pulp .................................................................. 124

Table 8.5 Bleaching conditions and optical properties of conventionally bleached and fungal bleached softwood kraft pulp ................................................................... 124

xixList of Tables

Table 8.6 Optical properties of conventionally bleached and fungal bleached pulps ........................................................ 125

Table 9.1 Quality of water entering dissolved air fl otation clarifi er ....................................................................... 153

Table 9.2 Quality of water exiting dissolved air fl otation clarifi er ........... 153 Table 9.3 Quality of reject stream ............................................................ 153

Table 10.1 Effect of enzyme treatment on beatability and strength properties of mixed pulp (60% waste corrugated kraft cuttings and 40% softwood) ............................................. 161

Table 10.2 PFI refi ning of OCC pulps ........................................................ 161 Table 10.3 Effect of enzyme treatment on power consumption

during manufacturing of ESKP high strength – Process-scale trial results ......................................................... 163

Table 10.4 Effect of enzyme treatment on power consumption during manufacturing of ESKP Normal – Process-scale trial results ................................................................................ 164

Table 10.5 Effect of enzyme treatment on power and steam consumption during coating base manufacture – Process-scale trial results ......................................................... 164

Table 10.6 Effect of enzyme treatment on power consumption during manufacturing of high gsm base papers (super coated art board 122 gsm and art paper 102 gsm) ......... 164

Table 10.7 Effect of enzyme treatment on the drainability of OCC ........... 169 Table 10.8 Effect of enzyme treatment on CSF of different

types of pulp ............................................................................. 173 Table 10.9 Effect of enzyme dose on CSF and strength

properties of OCC ..................................................................... 173Table 10.10 Effect of enzyme treatment on the requirement

for cationic polyacrylamide for drainage control of OCC ......................................................................... 173

Table 10.11 Effect of cellulase and pectinase enzymes on drainageof deinked pulp ......................................................................... 174

Table 10.12 Benefi ts of improving drainage ................................................ 176Table 10.13 Effect of enzymes on vessel pick reduction ............................. 178Table 10.14 Reduction in vessel element picking by fi ber

modifi cation enzymes in mill trial ............................................ 178

Table 11.1 Methods used for improving pulp cleanliness .......................... 186 Table 11.2 Effect of different xylanase enzymes on shive removal

factor and bleach boosting ........................................................ 187 Table 11.3 Effect of Shivex on shive counts and shive factor

in different bleaching stages at varying kappa factor ............... 188 Table 11.4 Effect of Shivex on shive removal factors (Sf) ......................... 189 Table 11.5 Shive removal in different bleaching sequences ....................... 190

xx List of Tables

Table 12.1 Derivatives and end-use products from dissolving pulp ........... 194 Table 12.2 Effect of xylanase enzyme from Schizophyllum

commune on removal of hemicellulose from delignifi ed mechanical aspen pulp ............................................ 196

Table 12.3 Effect of xylanase enzyme from S. commune on pentosan content and viscosity of chemical pulp ..................... 196

Table 12.4 Effect of xylanase enzyme from Escherichia coli on pentosan removal from dissolving pulp ............................... 197

Table 12.5 Effect of successive xylanase treatments from Saccharomonospora virdis for selective removal of xylan from bleached birchwood kraft pulp .......................... 197

Table 12.6 Effect of xylanase from Trichoderma harzianum on xylan content of unbleached and bleached kraft pulps ................................................................................. 198

Table 12.7 Effect of xylanase enzyme from Aureobasidium pullulans on pentosans from bleached sulfi te dissolving-grade pulp ............................................................... 199

Table 12.8 Effect of xylanase enzyme from A. pullulans on properties of unbleached sulfi te pulps ................................. 200

Table 12.9 Effect of xylanase enzyme from A. pullulans on properties of sulfi te pulp ...................................................... 201

Table 12.10 Bleaching of sulfi te pulp with A. pullulans xylanase and reduced amount of active chlorine in OD1EOD2H sequence.......................................................... 201

Table 12.11 Properties of pulp before and after treatment with A. pullulans hemicellulases and alkali.............................. 202

Table 13.1 The effect of various technologies on effl uent parameters .............................................................. 212

Table 13.2 Chlorinated organic compounds in bleach plant effl uents ........................................................................... 214

Table 13.3 Reported activated sludge removal effi ciencies for chlorophenols ...................................................................... 221

Table 13.4 Reported activated sludge removal effi ciencies for chlorophenols ...................................................................... 224

Table 13.5 Reduction of COD and AOX in the continuous reactor by anaerobic treatment.............................................................. 230

Table 13.6 Removal of pollutants by anaerobic–aerobic treatment of bleaching effl uent ................................................................. 231

Table 13.7 Removal of pollutants with ultrafi ltration plus anaerobic/aerobic system and the aerated lagoon technique ....................................................................... 233

Table 13.8 Effect of treatment with C. subvermispora CZ-3 on chlorophenols and chloroaldehydes in the effl uent from extraction stage ................................................................ 242

xxiList of Tables

Table 13.9 Effect of treatment with R. oryzae on chlorophenols and chloroaldehydes in the effl uent from extraction stage ......................................................................... 243

Table 13.10 Comparison of systems used for the treatment of bleaching effl uents with different fungi in batch process ........................................................................ 248

Table 13.11 Comparison of systems used for the treatment of bleaching effl uents with different fungi in continuous process................................................................ 249

Table 14.1 Primary characteristics of biofi lms and general paper machine deposition ......................................................... 264

Table 14.2 Levanase-producing bacteria .................................................... 266 Table 14.3 Microorganisms commonly found in mill environment ........... 269 Table 14.4 Comparison of biological activity test methods ....................... 278 Table 14.5 Effect of tetrakishydroxymethylphosphonium sulfate

(THPS) against Enterobacter aerogenes and SRB ................... 287 Table 14.6 Effect of THPS on Activated sludge in the biological

effl uent treatment (BET) plant .................................................. 287 Table 14.7 Effect of Bimogard on EPS after introduction

to a mill previously using biocides ........................................... 292 Table 14.8 Modes of action of microbicides, biodispersants,

enzymes, and biofi lm inhibitors................................................ 296 Table 14.9 Colony count of slime-forming bacteria (S-1)

following application of a synthetic biocide MBT and combined application of MBT and the corresponding bacteriophage (PS-1) ........................................ 297

Table 15.1 Savings realized by switching to enzymatic stickies control at a 400 tpd coated paperboard mill (Based on Patrick (2004)) ......................................................... 312

Table 17.1 Typical off-gas characteristics of kraft pulp mill ...................... 328 Table 17.2 Odor threshold concentration of TRS pollutants ...................... 329 Table 17.3 Typical emissions of Sox and NOx from kraft

pulp mill combustion sources ................................................... 329 Table 17.4 Microbial cultures used for degradation of pollutants .............. 334

Table 19.1 Emerging biorefi ning technologies ........................................... 378 Table 19.2 Benefi ts of hemicellulose preextraction ................................... 380 Table 19.3 Possible products from syngas ................................................. 390 Table 19.4 Relative emissions rates of different emissions ........................ 392