Table Of ContentBiotechnology for Environmental Protection
in the Pulp and Paper Industry
Springer
Berlin
Heidelberg
New York
Barcelona
Budapest
Hong Kong
London
Milan
Paris
Singapore
Tokyo
Dr. PRATIMA BATPAI
Dr. PRAMOD K. BATPAI
Thapar Corporate Research & Development Centre
Chemical Engineering Division
PO Box 68
147001 Patiala
India
Professor Dr. RYUICHIRO KONDO
Kyushu University
Department of Forest Products
Faculty of Agriculture
Hakozaki, Higashi-ku
812-8581 Fukuoka
Japan
ISBN-13: 978-3-642-64271-5
Library of Congress Cataloging-in-Publication Data
Bajpai, P. (Pratima)
Biotechnology for environmental protection in the pulp and paper
industry 1 Pratima Bajpai, Pramod K. Bajpai, Ryuichiro Kondo.
p. cm.
Includes bibliographical references.
ISBN-13: 978-3-642-64271-5 e-ISBN-13: 978-3-642-60136-1
DOl: 10.107/978-3-642-60136-1
I. Wood-pulp - Biotechnology. 2. Wood-pulp industry - Environmental
aspects. 3. Paper industry - Environmental aspects. 4. Paper
chemistry. I. Bajpai,'Pramod K. II. Kondo, Ryuichiro, 1949- _
III. Title.
TS1l76.6.B56B35 1999
676'.042 -dc21 99-30761
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SPIN 10693384 30/3136 - 5 4 3 2 1 0 - Printed on acid-free paper
P. Bajpai . P.K. Bajpai . R. Kondo
Biotechnology
for Environmental Protection
in the Pulp
and Paper Industry
With 27 Figures and 104 Tables
Springer
Acknowledgements
We are grateful to Professor Kokki Sakai for his constant support and encour
agement in the execution of this project. Our heartfelt gratitude goes to Mr.
Koki Fujita for his assistance in a number of tasks in the preparation of this
manuscript. We would also like to express our thanks to Dr. I. Reid for sug
gesting a few good topics for this book. We offer our sincere thanks to the
friends and organizations who provided us with information on the latest
advances in their respective areas.
Sincere appreciation is extended to Ms. Chie Takatsuka, Ms. Chie Ishihara,
and Ms. Hirano Makiko for their help in word processing in the early stages of
the preparation of the manuscript and to Mrs. Katsuko Mori for secretarial
assistance. We would like to thank all the students/research scholars of the
Wood Chemistry, Forest Products Department of Kyushu University for their
help and cooperation.
PKB and PB wish to express their particular gratitude to Professor M.P.
Kapoor for granting them sabbatical leave to work at Kyushu University, and
for supporting them on every step of the way. We were lucky to have numer
ous peoples' help with various parts of this work. We are grateful to Mr. S.S.
Gill for his invaluable help in word processing in the final stages of prepara
tion. Also to Mr. A. Sappal and Mr. S.N. Sharma for their help in typing some
chapters. The valuable help provided by Mr. S.S. Saini and Mr. B.c. Saini in
preparing the drawings and figures and by Mr. S.P. Mishra, Mr. O.P. Mishra and
Mr. Sanjay Kumar in proofreading and general organization are gratefully
acknowledged. Our thanks also go to many others who gave us permission to
use drawings and other illustrative material.
Finally, we thank Springer-Verlag for their efforts in publishing the book.
P. BAJPAI, P.K. BAJPAI, and R. KONDO
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 Wood Pretreatment to Remove Toxic Extractives. . . . . . . . . . . . . . . . 13
3 Biopulping: a Less Polluting Alternative to CTMP . . . . . . . . . . . . . . . 29
4 Pulp Bleaching with Xylanases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
5 Pulp Bleaching with White Rot Fungi and Their Enzymes. . . . . . . . 65
6 Enzymatic Deinking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
7 Treatment of Wastewaters with Anaerobic Technology. . . . . . . . . . . 109
8 Decolorization and Detoxification of Bleached Kraft Effluents. . . .. 141
9 Purification of Process Water In Closed-Cycle Mills. . . . . . . . . . . . . 171
10 Management of Wastewater Treatment Sludges.. ... .. . .. . .. .. . . 209
11 Biofiltration of Exhaust Gases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 239
Subject Index.. ... . . .. . . . ... ... . .. . .. . . . .. .. . .. ... .. . .. .. . 263
1 Introduction
The pulp and paper industry comprises a large and growing portion of the
world's economy. Pulp and paper production has increased globally and will
continue to increase in the near future. Approximately 155 million tons of wood
pulp are produced worldwide and about 260 million are projected for the
year 2010.1 However, the industry is very capital-intensive, with small profit
margins, which tends to limit experimentation, development, and incorpora
tion of new technologies into the mills. To be able 'to cope with increasing
demand, an increase in productivity and improved environmental perfor
mance is needed, as the industry is also under constant pressure to reduce and
modify environmental emissions to air and water.
In the US, the pulp and paper industry ranks third, after primary metals and
the chemical industry, in terms of freshwater withdrawal. It is believed that by
the year 2000, the paper industry will have become the largest manufacturing
user of water.2 However, the industry ranks fifth among the major industries
in its contribution to the water-pollution problem, having thus had significant
impact on the nation's streams; but the situation is improving rather than
growing worse. Since 1976, many mills have built secondary biological waste
treatment plants, by 1991,99% of the pulp and paper industry in US had sec
ondary treatment or its equivalent. The fact that the majority of the mills have
wastewater treatment has had a visible beneficial effect on water quality.
Like any other large-scale industry, the pulp and paper industry exerts its
own impact on the environment. Although the situation is improving year by
year, pulp mills still release unpleasantly smelling sulfur compounds into the
air and discharge wastewaters which enhance eutrophication and have toxic
effects on the surrounding biota. Organochlorine compounds formed during
the bleaching of chemical pulp have attracted most attention in recent years.
Environmental Regulations
While not all AOX (adsorbable organic halides) compounds are harmful to
health or the environment, a number of them have been determined to be so.
Rather than single out the harmful constituents of AOX for regulatory pur
poses, regulatory agencies in Canada and Scandinavian countries have used
AOX as the measure by which to set limits on different discharges. Such regu
lations have forced the pulp and paper industry in Europe, Canada, and Japan,
2 1 Introduction
and recently in the USA3 also, to reduce AOX discharges through a combina
tion of process modifications and effluent treatment technologies.
Europe
While environmental regulations provided the impetus for the drive towards
AOX reduction, today it is market force which is sustaining it. The Scandina
vian industry today is moving beyond AOX reduction as a solution, and
working towards total elimination of effluent discharge as the long-term solu
tion to environmental problems. The Scandinavian pulp and paper industry is
thoroughly convinced of the need to reduce and even eliminate AOX
discharges. It does not require pressure from environmental regulations to
spur it.
In Sweden, the Licensing Board for Environmental Protection is an
autonomous body responsible for setting the terms and conditions for grant
ing of environmental permits. The board takes into account ecological, tech
nological, and economical factors in setting the terms for permits. Regulatory
limits for pulp and paper mills are set on an individual, case-by-case basis. As
such, there is no set of effluent limits for the industry as a whole. However, the
regulations are fairly similar for mills that produce a similar product; conse
quently, from an exhaustive survey of discharge limits in place at the various
mills, one can determine allowable discharge levels for mills producing differ
ent products. In general terms, Table 1.1 lists the limits for discharges from
pulp mills in Sweden.4 Regulations required that by the end of 1995, all mills
decrease their emissions of organic chlorine to 1 kg/ton for softwood kraft
pulp, and 0.5 kg/ton for sulfite or hardwood kraft pulp, which has been further
reduced to 0.5 and 0.3 kg/ton, respectively.
Table 1.1. Regulatory emission limits for Swedish pulp mills
Parameter Discharge limit (kg/ton pulp)
1991 1995 1999
BODs 10-20
COD 10-20
TSS 40-70
TOCI Softwood 2.0 1.0 0.5
Hardwood 1.0 0.5 0.3
AOX Softwood 2.5
Hardwood 1.3
Nitrogen 0.3
Phosphorus 0.1
Based on data from Ref. 4.
Environmental Regulations 3
In Finland, regulatory trends in general have closely followed those in
Sweden. The AOX discharge has steadily decreased from 3.7 kg/ton in 1989 to
less than 1 kg/ton by 1995.
Effluent discharge limits in Norway are imposed and permits granted by the
State Pollution Control Authority on a mill-by-mill basis, based on the condi
tions of the receiving body of water, with limits being stricter for discharge to
lakes and. fjords than to the sea.
Effluent regulations in Germany are set up by the Ministry of Environment,
based on recommendations by various experts. The enforcement of the regu
lations is through the levying of what is known as discharge fees. Mills that
exceed the discharge limits set by the regulations are liable to pay the discharge
fees. The effluent limits for pulp and paper mills in Germany are given in Table
1.2.5
French regulations do not have AOX standards or discharge limits; however,
mills are expected to measure their AOX discharge levels periodically. The reg
ulations do set discharge limits for TSS, BODs, and··COD for pulp and non
integrated paper mills.
Portugal has specific emission limits for discharges to water from pulp and
integrated paper mills as shown in Table 1.3.5 Regulations for general chemi
cal industries are applicable to nonintegrated paper mills.
In Austria, the AOX discharge limit was fixed at O.75-1.5kg/ton in 1994,
which has been further reduced to O.5-1.0kg/ton after 1995.6
Table 1.2. Regulatory emission limits for pulp and paper mills in
Germany
Mill type Discharge limit (kg/ton)
BODs COD AOX
Paper Mills
Wood-free unsized 3 0.04
Wood-free sized 2 6 0.04
Wood-free highly refined 3 9 0.04
Wood-free coated 2 0.02
Wood-containing 3(5)" 0.01
Recycle fiber-based 5 0.012
Chemical pulp mills 5b 70b 1.0
"COD of 5 kg/ton when >50% of pulp is TMP, or when a substantial
part of the pulp is bleached with peroxide.
b24-h composite samples.
Based on data from Ref. 5.
4 1 Introduction
Table 1.3. Discharge limits for pulp and integrated paper mills in
Portugal
Mill type Discharge limit (kg/ton)
TSS BODs COD AOX
Unbleached kraft pulp
-
1991 2.5 5
1996 1.5 3 35
Bleached kraft pulp
1991 10 9
1996 3 6 50 1.5
Bleached sulfite pulp
1991 12.5 45
1996 6 25 120 1.5
Integrated kraft liner
1991 4 6
1996 2 4 30
Based on data from Ref. 5.
Table 1.4. AOX discharge limits in Canada
Province Year AOX limit (kg/ton)
Ontario 1991 2.5
British Columbia 1992-1993 2.5 (Softwood)
3.8 (Hardwood)
Quebec 1992 2.5 (Softwood)
1.5 (Hardwood)
1995 1.5 (Softwood)
0.5 (Hardwood)
Based on data from Ref. 7.
North America
Canada, though behind Scandinavia in achieving AOX reduction goals, is
aggressively setting targets and demanding that its pulp and paper industry
meet them. Tables 1.4 and 1.5 summarize the salient points of regulations by
the various provinces.7 The regulations developed by British Columbia (Table
1.5) are the most stringent in the country. Very similar regulations are being
developed by Ontario.
the United States did not have specific discharge limits on AOX, but did
have a limit on dioxin discharge. The Clean Water Act of 1987 listed dioxin as
a toxic compound. In an exhaustive study of 104 US bleached pulp mills in
1988-1989, the EPA measured concentrations of 2,3,7,8-TCDD and 2,3,7,8-
TCDF in the effluents. A further in-depth study of 25 mills resulted in the con-
