Aquaculture Engineering

433 Pages·2013·56.663 MB·English

by  Odd-Ivar Lekang

aquaculture engineering
ea aquaculture
second edition nq
Odd-ivar Lekang
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aquaculture has been expanding at a rate of 9% per year for more than 20 years, and is projected to ia
continue growing at a very rapid rate into the foreseeable future. in this completely updated and revised n engineering
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new edition of a highly successful, best-selling and well-received book, Odd-ivar Lekang provides the latest
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must-have information of commercial importance to the industry, covering the principles and applications of u
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all major facets of aquaculture engineering.
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every aspect of the growing field has been addressed with coverage spanning water transportation and t
treatment; feed and feeding systems; fish transportation and grading; cleaning and waste handling; and iu
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instrumentation and monitoring. also included in this excellent new edition are comprehensive details of
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major changes to the following subject areas: removal of particles; aeration and oxygenation; recirculation g
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and water reuse systems; ponds; and the design and construction of aquaculture facilities. Chapters
providing information on how equipment is set into systems, such as land-based fish farms and cage farms,
are also included, and the book concludes with a practical chapter on systematic methodology for planning
a full aquaculture facility. s
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Fish farmers, aquaculture scientists and managers, engineers, equipment manufacturers and suppliers to c
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the aquaculture industry will all find this book an invaluable resource. Aquaculture Engineering, Second
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edition, will be an essential addition to the shelves of all libraries in universities and research establishments
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where aquaculture, biological sciences and engineering are studied and taught.

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about the author i
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odd-ivar lekang is associate Professor of aquaculture engineering at the department of Mathematical io
Sciences and Technology at the norwegian University of Life Sciences in Ås. n second edition
also available from Wiley-blackWell
Odd-ivar Lekang
aquaculture and behavior aquaculture L
edited by F Huntingford, M Jobling & S kadri Second edition e
9781405130899 edited by J Lucas and P Southgate k
aquaculture Production systems 9781405188586 a
edited by J Tidwell Journal of the World aquaculture society n
9780813801261 Print iSSn: 0893-8849, Online iSSn: 1749-7345
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ISBN 978-0-470-67085-9
9 780470 670859
Lekang_Aquaculture_9780470670859_hb.indd 1 17/12/2012 16:52

Aquaculture Engineering

Aquaculture Engineering
Second Edition
Odd-Ivar Lekang
Associate Professor of Aquaculture Engineering
Department of Mathematical Sciences and Technology
Norwegian University of Life Sciences
Drobakveien 31
1432 Ås
Norway
A John Wiley & Sons, Ltd., Publication
This edition first published 2013 © 2013 by John Wiley & Sons, Ltd.
First edition published 2007 © 2007 by Odd-Ivar Lekang
Wiley-Blackwell is an imprint of John Wiley & Sons, formed by the merger of Wiley’s global Scientific, Technical
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Library of Congress Cataloging-in-Publication Data
Lekang, Odd-Ivar, author.
Aquaculture engineering / Odd-Ivar Lekang, Department of Mathematical Sciences and Technology, Norwegian University of
Life Sciences, Drobakveien, Norway. – Second Edition.
pages cm
Includes bibliographical references and index.
ISBN 978-0-470-67085-9 (hardback) – ISBN (invalid) 978-1-118-49607-7 (obook) – ISBN (invalid) 978-1-118-49861-3 (emobi)
1. Aquacultural engineering. I. Title.
SH137.L45 2013
639′.8–dc23
2012040911
A catalogue record for this book is available from the British Library.
Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in
electronic books.
Cover images: Main image: Large land-based on-growing fish farm. Smaller images (from left to right): Fish distribution in a
tank with optimal flow conditions; UV light used for disinfection of inlet water to a fish farm (see figure 10.2 in chapter 10 for
more details); Well boat collecting fish from sea cages for slaughtering.
Cover design by Meaden Creative
Set in 9.5/11.5pt Times Ten by SPi Publisher Services, Pondicherry, India
1 2013
Contents
Preface xv
1 Introduction 1
1.1 Aquaculture engineering 1
1.2 Classification of aquaculture 1
1.3 The farm: technical components in a system 2
1.3.1 Land-based hatchery and juvenile production farm 2
1.3.2 On-growing sea cage farm 4
1.4 Future trends: increased importance of aquaculture engineering 5
1.5 This textbook 6
References 6
2 Water Transport 7
2.1 Introduction 7
2.2 Pipe and pipe parts 7
2.2.1 Pipes 7
2.2.2 Valves 11
2.2.3 Pipe parts: fittings 12
2.2.4 Pipe connections: jointing 12
2.2.5 Mooring of pipes 13
2.2.6 Ditches for pipes 14
2.3 Water flow and head loss in channels and pipe systems 15
2.3.1 Water flow 15
2.3.2 Head loss in pipelines 16
2.3.3 Head loss in single parts (fittings) 18
2.4 Pumps 19
2.4.1 Types of pump 19
2.4.2 Some definitions 19
2.4.3 Pumping of water requires energy 22
2.4.4 Centrifugal and propeller pumps 23
2.4.5 Pump performance curves and working point for centrifugal pumps 26
2.4.6 Change of water flow or pressure 28
2.4.7 Regulation of flow from selected pumps 29
References 31
v
vi Contents
3 Water Quality and Water Treatment: An Introduction 32
3.1 Increased focus on water quality 32
3.2 Inlet water 32
3.3 Outlet water 33
3.4 Water treatment 35
References 36
4 Fish Metabolism, Water Quality and Separation Technology 37
4.1 Introduction 37
4.2 Fish metabolism 37
4.2.1 Overview of fish metabolism 37
4.2.2 The energy budget 38
4.3 Separation technology 39
4.3.1 What are the impurities in water? 39
4.3.2 Phosphorus removal: an example 41
References 42
5 Adjustment of pH 43
5.1 Introduction 43
5.2 Definitions 43
5.3 Problems with low pH 44
5.4 pH of different water sources 44
5.5 pH adjustment 45
5.6 Examples of methods for pH adjustment 45
5.6.1 Lime 45
5.6.2 Sea water 47
5.6.3 Lye or hydroxides 47
References 48
6 Removal of Particles: Traditional Methods 50
6.1 Introduction 50
6.2 Characterization of the water 51
6.3 Methods for particle removal in fish farming 51
6.3.1 Mechanical filters and microscreens 52
6.3.2 Depth filtration: granular medium filters 55
6.3.3 Settling or gravity filters 58
6.3.4 Integrated treatment systems 60
6.4 Hydraulic loads on filter units 62
6.5 Purification efficiency 62
6.6 Dual drain tank 63
6.7 Local ecological solutions 64
References 64
7 Protein Skimming, Flotation, Coagulation and Flocculation 66
7.1 Introduction 66
7.1.1 Surface tension, cohesion and adhesion 68
7.1.2 Surfactants 70
7.2 Mechanisms for attachment and removal 71
7.2.1 Attachment of particles to rising bubbles by collision, typically
in flotation 72
7.2.2 Improving colloid and particle removal rates: pretreatment 73
Contents vii
7.2.3 Attachment of surface-active substances, typically in protein skimmers 78
7.2.4 Particle attachment by nucleation 80
7.3 Bubbles 80
7.3.1 What is a gas bubble? 80
7.3.2 Methods for bubble generation 80
7.3.3 Bubble size 82
7.3.4 Bubble coalescence 83
7.4 Foam 83
7.4.1 What is foam? 83
7.4.2 Foam stability 84
7.4.3 Foam breakers 85
7.5 Introduction of bubbles affects the gas concentration in the water 85
7.6 Use of bubble columns in aquaculture 85
7.7 Performance of protein skimmers and flotation plants in aquaculture 86
7.7.1 What is removed in inlet or effluent aquaculture water with
the use of protein skimmers? 86
7.7.2 Factors affecting the efficiency of protein skimming in aquaculture 87
7.7.3 Use of ozone 89
7.7.4 Bubble fractionation 89
7.8 Design and dimensioning of protein skimmers and flotation plants 90
7.8.1 Protein skimmers: principles and design 90
7.8.2 Protein skimmers: dimensioning 92
7.8.3 Flotation plant 92
7.8.4 Important factors affecting design of a DAF plant 93
References 95
8 Membrane Filtration 99
8.1 History and use 99
8.2 What is membrane filtration? 100
8.3 Classification of membrane filters 101
8.4 Flow pattern 103
8.5 Membrane shape/geometry 104
8.6 Membrane construction/morphology 105
8.7 Flow across membranes 106
8.8 Membrane materials 106
8.9 Fouling 107
8.10 Automation 108
8.11 Design and dimensioning of membrane filtration plants 108
8.12 Some examples of results with membranes used in aquaculture 112
References 112
9 Sludge Production, Treatment and Utilization 114
9.1 What is the sludge? 114
9.2 Dewatering of sludge 114
9.3 Stabilization of sludge 115
9.4 Composting of the sludge: aerobic decomposition 115
9.5 Fermentation and biogas production: anaerobic decomposition 117
9.6 Addition of lime 118
9.7 Utilization of sludge 118
References 118
viii Contents
10 Disinfection 120
10.1 Introduction 120
10.2 Basis of disinfection 121
10.2.1 Degree of removal 121
10.2.2 Chick’s law 121
10.2.3 Watson’s law 121
10.2.4 Dose–response curve 122
10.3 Ultraviolet light 122
10.3.1 Function 122
10.3.2 Mode of action 122
10.3.3 Design 123
10.3.4 Design specification 124
10.3.5 Dose 125
10.3.6 Special problems 125
10.4 Ozone 125
10.4.1 Function 125
10.4.2 Mode of action 125
10.4.3 Design specification 126
10.4.4 Ozone dose 127
10.4.5 Special problems 127
10.4.6 Measuring ozone content 128
10.5 Advanced oxidation technology 129
10.5.1 Redox potential 129
10.5.2 Methods utilizing AOT 130
10.6 Other disinfection methods 131
10.6.1 Photozone 131
10.6.2 Heat treatment 131
10.6.3 Chlorine 131
10.6.4 Changing the pH 132
10.6.5 Natural methods: ground filtration or constructed wetland 132
10.6.6 Membrane filtration 132
References 132
11 Heating and Cooling 134
11.1 Introduction 134
11.2 Heating requires energy 134
11.3 Methods for heating water 135
11.4 Heaters 136
11.4.1 Immersion heaters 136
11.4.2 Oil and gas burners 137
11.5 Heat exchangers 138
11.5.1 Why use heat exchangers? 138
11.5.2 How is the heat transferred? 138
11.5.3 Factors affecting heat transfer 139
11.5.4 Important parameters when calculating the size of heat exchangers 140
11.5.5 Types of heat exchanger 141
11.5.6 Flow pattern in heat exchangers 144
11.5.7 Materials in heat exchangers 144
11.5.8 Fouling 145
11.6 Heat pumps 146
11.6.1 Why use heat pumps? 146