Process Technologies for Water Treatment

250 Pages·1988·7.619 MB·English

by  Samuel Stucki (auth.)

PROCESS
TECHNOLOGIES
FOR WATER
TREATMENT
Earlier Brown Boveri Symposia
1969 Flow Research on Blading
Edited by L. S. Dzung
1971 Real-Time Control of Electric Power Systems
Edited by E. Handschin
1973 High-Temperature Materials in Gas Turbines
Edited by P. R. Sahm and M. O. Speidel
1975 Nonemissive Electrooptic Displays
Edited by A. R. Kmetz and F. K. von Willisen
1977 Current Interruption in High-Voltage Networks
Edited by K. Ragal/er
1979 Surges in High-Voltage Networks
Edited by K. Ragal/er
1981 Semiconductor Devices for Power Conditioning
Edited by R. Sittig and P. Roggwil/er
1983 Corrosion in Power Generating Equipment
Edited by M. O. Speidel and A. Atrens
1985 Computer Systems for Process Control
Edited by Reinhold Giith
PROCESS
TECHNOLOGIES
FOR WATER
TREATMENT
Edited by
Samuel Stucki
Asea Brown Bover;, Ltd.
Baden, Switzerland
PLENUM PRESS • NEW YORK AND LONDON
Library of Congress Cataloging in Publication Data
Brown Boveri Symposium on Process Technologies for Water Treatment (1987: Brown
Boveri Research Center)
Process technologies for water treatment / edited by Samuel Stucki.
p. cm.
"Proceedings of the tenth Brown Boveri Symposium on Process Technologies for
Water Treatment, held September 21-22,1987, in Baden, Switzerland"-T.p. verso.
Includes bibliographical references and inex.
ISBN 978-1-4684-8558-5 ISBN 978-1-4684-8556-1 (eBook)
DOI 10.1007/978-1-4684-8556-1
1. Water-Purification-Congresses.1. Stucki, Samuel. II. Title.
TD433.B76 1987 88-21918
628.1'62-dcI9 CIP
Proceedings of the Tenth Brown Boveri Symposium on Process Technologies for Water
Treatment, held September 21-22, 1987, in Baden, Switzerland
© 1988 Plenum Press, New York
Softcover reprint of the hardcover 1s t edition 1988
A Division of Plenum Publishing Corporation
233 Spring Street, New York, N.Y. 10013
All rights reserved
No part of this book may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, microfilming,
recording, or otherwise, without written permission from the Publisher
v
Foreword
The Brown Boveri Scientific Symposia by now are part of a firmly established tradition. This
is the tenth event in a series which was initiated shortly after Corporate Research was created
as a separate entity in our company; the symposia are held every other year. The themes have
been:
1969 Flow Research on Blading
1971 Real-Time Control of Electric Power Systems
1973 High-Temperature Materials in Gas Turbines
1975 Nonemissive Electrooptic Displays
1977 Current Interruption in High-Voltage Networks
1979 Surges in High-Voltage Networks
1981 Semiconductor Devices for Power Conditioning
1983 Corrosion in Power Generating Equipment
1985 Computer Systems for Process Control
1987 Process Technologies for Water Treatment
The tenth event in an uninterrupted series that by now goes back almost 20 years is a good
opportunity to make a few remarks on the guiding rules that have governed our symposia.
Why have we chosen these titles? At the outset we establislwd certain selection criteria; we
felt that a subject for a symposium should fulfill the following three requirements:
It should characterize a part of an established discipline; in other words, it
should describe an area of scholarly study and research.
It should be of current interest in the sense that important results have recently
been obtained and considerable research is still being undertaken in the world's
scientific community.
It should bear some relation to the scientific and technological activity of the
company.
Let us look at the requirement "current interest": Some of the topics on our list of titles have
been the object of research for several decades, some even from the beginning of the century.
One might wonder, then, why such fields could be called particularly timely in the 70's and
80's. Let me make a few remarks on this subject. The reason is the following:
Experience shows that scientific progress in most areas does not occur at a constant rate -
it comes in waves that are often followed by periods where successful research activity comes
to a standstill. The waves are often sparked by an external event that may come from quite an
unexpected comer. Our symposium subjects have always been chosen so as to coincide with
such a wave, and the present one is no exception, as I will point out.
Along with electricity, water is one of the basic commodities which will be needed in ever
increasing quantities as the industrialization and urbanization of our world progresses. The
challenge of rising demand can only be met if we learn to apply all suitable scientific and
vi Foreword
technical resources available to us in stepping up the productivity of process technologies for
turning low grade water into pure water.
Moreover, at the fast moving frontiers where new industrial products are developed and
manufactured, we observe that whenever the complexity and sophistication of those products
reach a higher level, so does the demand on the purity of the processing water required for
making them. Manufacture of semiconductor integrated circuits provides a clear example. The
removal of all foreign matter from the processing water is the ultimate goal. What now limits
further progress is not so much our ability to improve water purification, but rather the
sensitivity of the available measuring instruments for the reliable detection of residual matter.
But our theme does not end with Ultrapure water. There is a global awareness now of the
dangers of water contamination from industrial and other waste. The serious consequences that
this may have for humanity call for drastic remedial measures. Therefore, it is essential to
develop more efficient and economic processes to remove toxic or hazardous substances from
effluents. Failure to do so may endanger highly developed industries as the added cost of waste
water treatment may make production uneconomic. Today, improvements in handling waste
are becoming as important as product development in maintaining competitiveness.
As in previous meetings, the number of participants was limited in order to maintain the
character of a specialist meeting of restricted size, and it was with much regret that we were
forced to disappoint many who wished to participate but who could not be accommodated. We
hope that the publication of the present volume is a partial consolation for those whom we did
not have the pleasure of welcoming as our guests.
The Symposium was attended by 110 participants from 14 countries. It was both an honour
and a pleasure to welcome these scientists and engineers from so many different parts of the
world. Their willingness to travel to Baden to spend two full days with us was a challenge as
well as an obligation to us as organizers, and we sincerely hope that the expectations which
prompted them to attend were fulfilled.
To conclude, we should like to take this opportunity of expressing our sincere gratitude to
every Symposium participant. We hope they consider the time spent with us to have been
worthwhile. Thanks are due primarily to the authors for having spared no effort in preparing
their papers: the contents of this volume reflect the high quality of their work. We thank also
the participants in the discussions, both formal and informal, and the editor of these
proceedings.
The selection of the theme, the layout of the program and the contacting of the speakers were
the responsibility of Dr. S. Stucki, head of the Electrochemistry and Membrane Separations
Group at our Research Center. His careful and competent preparation was instrumental in the
success of the Symposium. Our thanks also go to Mr. H. Wilhelm and his staff for the smooth
running of the administrative side of the meeting.
On January 1, 1988, the Brown Boveri Company merged with ASEA AB, Sweden, to
become Asea Brown Boveri, or ABB, a multinational corporation. In this volume, the
affiliation of the speakers and participants has been listed as at the time of the symposium.
A.P. Speiser
Scientific Adviser of the Executive Board
of Asea Brown Boveri
formerly Director of Corporate Research
of Brown Boveri
vii
Preface
The goal of the 10th Brown Boveri Symposium was to give a summary of the state of the
art of advanced physical-chemical water treatment technologies, their prindples and their
applications in municipal and industrial water supplies. This volume contains the proceedings
of the symposium which was held at the Brown Boveri Research Center on September 21 and
22,1987.
Water treatment has become of increasing importance in a world of limited resources. The
quality standards required for health in the case of drinking water, or for reliability in the case
of industrial process water, necessitate improved technologies for the treatment of the water
before use, as well as before discharge.
The main body of the symposium consists of 12 invited papers covering a broad range of
subjects. The edited versions of the discussion sessions which were held after the oral
presentation of the papers at the symposium are included after each chapter.
It was originally planned to divide this volume into two parts: the fIrst dealing with the
principles of various treatment techniques, followed by a second part looking at their
applications. It turned out, however, that the distinction between "fundamental" and "applied"
papers was very arbitrary, and therefore this grouping was abandoned. The applications of the
various water treatment processes, such as membrane separation, UV, ozone or
electrochemical treatment or their combinations, range from heavily polluted waste water
streams from chemical plants to ultra-purifIcation of water for microelectronics manufacturing
processes.
The book opens with a key note lecture on water treatment by M.C. Kavanaugh, which
emphasizes (referring to the problem of haloform removal as a very illustrative example) the
importance of an improved chemical engineering approach to water treatment in guaranteeing
the quality standards imposed by the health authorities.
Two chapters focus on membrane separation processes. R. Rautenbach and I. Janisch show
that reverse osmosis (RO) membranes are capable of doing more than just removing ions.
Removal of organic contaminations by commercial RO modules seems feasible as a new
application ofRO in the fIeld of waste water treatment. In the following chapter an exhaustive
review of all the possible electrodialytic processes is given by the inventor of electrodialysis,
W. McRae. Electrodialysis, as the oldest membrane process for desalination of water, plays
an important role in brackish water desalination and is specially suited for applications in
remote or less developed areas of the world as it requires few chemicals.
Electrochemical water treatment has been used in the removing of heavy metals from the
waste water produced in galvanic and related processes. G. Kreysa discusses the various types
of electrochemical reactors which have been considered or used industrially for this purpose.
With proper design of the electrochemical cells, electrochemical removal of heavy metals
from waste water has proved to be a competitive process.
The state of the art of ozone generation by gas discharge is reviewed by U. Kogelschatz. The
implementation of the well-understood physics of the gas discharge processes in technical
equipment has led to a new generation of ozonizers with improved effIciency and, at the same
viii Preface
time, enhanced space-time yield. These improvements are a prerequisite for the large-scale use
of ozone in water technology.
A good knowledge of the chemistry of ozone in aqueous media is of practical importance
in two ways: it gives the engineer the necessary data about ozone demand and ozonation time;
and it provides a clue to the important problem of reaction products which have to be expected
from reactions of ozone with pollutants. J. Hoigne gives an authoritative review of the complex
aqueous chemistry of ozone.
H.P. Klein reviews the various uses of ozone in water treatment processes, emphasizing the
roles of process technology as well as of ozone production technology for optimum
performance of the process. Ifp roperly designed, ozonation alone or in combination with other
processes can perform a number of purification stages which are necessary in reaching a given
product quality from a given source.
Ultraviolet radiation is an alternative to chlorination or ozonation for disinfection purposes.
The photochemical mechanisms ofinactivation of microorganisms are discussed in the chapter
written by C. v. Sonntag. UV radiation of254 nm wavelength is found to be such an effective
disinfectant because it selectively induces irreversible photochemical reactions within the vital
DNA molecules of the microorganisms.
Water of extreme purity is required in various industrial processes to act as a chemical,
solvent or as a rinsing agent. Krapf and Preisser show the complexity of the problems that arise
if one is to guarantee the extremely high water purity standards required for microelectronic
manufacturing. If the tolerable impurity levels are in the range ofp arts per billion (ppb) to parts
per trillion (ppt), control of contamination becomes an intricate task comprising optimum
design of the purification equipment, trace analysis and monitoring of all possible classes of
contaminants, and flow design of the whole piping system.
A new process for the removal of trace organics from ultrapure water is presented in the
chapter by S. Stucki and H. Baumann. The combination of in-situ produced ozone with UV
radiation and mixed-bed polishing has proved to be a promising process for simultaneously
controlling TOC and biological contamination in ultrapure water systems.
Production processes in the chemical industry and in related industries (e.g. pulp and paper)
involve waste water that normally needs special treatment before it can be discharged into the
environment or into a municipal sewage system. E. Plattner and C. Comninellis compare in
their article the various possible approaches to removing soluble organic material from waste
water. These involve either separation processes (adsorption, membrane separation) or
oxidative transformation into a harmless end-product.
Power plants need huge quantities of water of diverse quality depending on how it is put to
use (ranging from boiler feed make-up to flue-gas scrubbing solutions). The paper of L.
Pelloni, A. K yas and I. Reimer shows that, by proper nesting of the various water streams taking
into account the range of purity levels present in a power station, considerable cost savings for
the raw material "water" are possible.
The collection of articles in this volume exemplifies the challenge that water treatment
poses. Water is a cheap commodity (quoted treatment costs range from a few cts/m3 to more
than 20 SPr 1m3) with, at the same time, very high purity standards (standard drinking water
has a purity of99 .5%!). Process technologies for water purification involve delicate separation
problems, i.e. the removal of small amounts of impurities from large volumes of water.
However, the resources allocated to these processes are limited, which means that, from the
multitude of possible technical solutions, the engineer has to solve the sometimes very delicate
problem of choosing the most economic process or combination of processes. The chapters in
this book clearly demonstrate the progress that has been made both in the physical chemistry
Preface IX
and in the chemical engineering of water treatment processes. But they also leave a number of
questions unanswered, which means that there is still need for further research and
development in order to refine and improve water treatment processes.
I would like to express my thanks to all those who contributed to the success of the
symposium and to the editing of the proceedings. First I am grateful to the authors of the papers
for agreeing to do the work of preparing their oral presentations as well as writing up the articles
reproduced here. I hope they will find that the result of their work, i.e. the present book, has
been worth their extra efforts. In preparing the scientific program of the symposium, I was
advised by Dr. C. Schiiler. I greatly appreciated his encouraging enthusiasm. For their help
before and during the symposium, I would like to thank Ms. B. Wullimann and all my
colleagues of the Electrochemistry and Membrane Separations Group.
The editing of the book would have been impossible without the assistance of Ms. J. Nehring,
who not only typed all the manuscripts, but also masterfully checked that all the references,
captions, etc., were eventually brought into a coherent and correct form. Dr. S. Dingwall did
an excellent job polishing our English and pointing out any linguistic inconsistencies in the
articles and discussions. The camera-ready layout, including the sizing of the figures and the
text, was prepared very skillfully by Mr. A. Miquel. Many thanks to all of them!
Baden, April 1988 S. Stucki
xi
Contents
List of Participants .............................................................................................................. xiii
WATER TREATMENT
M. C. Kavanaugh ......................................................................................................... 1
Discussion .................................................................................................................. 23
REVERSE OSMOSIS FOR lliE SEPARATION OF ORGANICS FROM AQUEOUS SOLUTIONS
R. Rautenbach and I. Janisch ..................................................................................... 25
Discussion .................................................................................................................. 42
ELECTRODIALYSIS
W.McRae ................................................................................................................... 45
Discussion .................................................................................................................. 61
REACfOR DESIGN FOR ELECTROCHEMICAL WATER TREATMENT
G. Kreysa .................................................................................................................... 65
Discussion .................................................................................................................. 84
ADVANCED OzONE GENERATION
U. Kogelschatz ........................................................................................................... 87
Discussion ................................................................................................................ 119
THE CHEMIS1RY OF OzoNE IN WATER
J. Hoigne ................................................................................................................... 121
Discussion ................................................................................................................ 142
OzONE IN WATER TREATMENT PROCESSES
H.P. Klein ................................................................................................................. 145
Discussion ................................................................................................................ 157
DISINFECTION WIlli UV-RADIATION
C. von Sonntag ......................................................................................................... 159
Discussion ................................................................................................................ 178
HIGH-PURITY WATER FOR SEMICONDUCTOR MANUFACfURING
E. Krapf and R. Preisser ........................................................................................... 181
Discussion ................................................................................................................ 189