AERATION: Principles and Practice ( VOLUME 11 ) - Chapter 1 ppsx

AERATION: Principles and Practice VOLUME 11 WATER QUALITY MANAGEMENT LIBRARY LIBRARY EDITORS W... Theory and Practice—Second Edition Second Edition Second Edition Reference Text on Proce

AERATION: Principles and Practice VOLUME 11

WATER QUALITY MANAGEMENT LIBRARY LIBRARY EDITORS

W W ECKENFELDER

J F MALINA, JR.

J W PATTERSON

WATER QUALITY MANAGEMENT LIBRARY

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STORMWATER MANAGEMENT Volume 10 WASTEWATER RECLAMATION AND REUSE Volume 11 AERATION: Principles and Practice

C RC PR E S S

AERATION:

Principles and Practice VOLUME 11

WATER QUALITY MANAGEMENT LIBRARY

James A Mueller, Ph.D., P.E William C Boyle, Ph.D., P.E.

H Johannes Pöpel, Dr.-Ing

LIBRARY EDITORS

W W ECKENFELDER

J F MALINA, JR.

J W PATTERSON

with significant contributions from:

Martin Wagner David E Gibson Yeong-Kwan Kim

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No claim to original U.S Government works International Standard Book Number 1-56676-948-5 Library of Congress Card Number 2001052466 Printed in the United States of America 1 2 3 4 5 6 7 8 9 0

Printed on acid-free paper

Library of Congress Cataloging-in-Publication Data

Mueller, James A.

Aeration : principles and practice / James A Mueller, William C Boyle, H Johannes Pöpel ; with significant contributions from Martin Wagner, David E Gibson, Yeong-Kwan Kim.

p cm — (Water quality management library) Includes bibliographical references and index.

ISBN 1-56676-948-5 (alk paper)

1 Sewage—Purification—Aeration I Boyle, William C (William Charles), 1936– II Pöpel, H Johannes III Title IV Series.

TD758 M84 2002 628.3 ′ 5—dc21 2001052466

CIP

To our wives:

MaryBeth, Nancy, and Ursula

The use of aeration in the wastewater treatment field has been in existence for over

a century Each of the authors has been involved with the theory and application of aeration systems for a little less than half a century It was a daunting task to put together what we considered the important principles underlying the mechanisms involved in aeration and show how they are applied in practical applications The objective was to not only provide the basic theory, but also the current practice and latest applications, so the book would be useful to today’s professional engineers as well as to future engineers now studying the field

The task was conceived in the early 1990s by Wes Eckenfelder, who recognized

a gap in the field After a number of false starts, and with Bill and I soliciting the assistance of Johannes at the WEF convention in Chicago in 1997, it was begun in earnest in 1998—taking several years to complete Johannes supplied an in-depth theoretical background as well as the European experience, especially in deep tank aeration Bill supplied his experience in the diffused aeration area, and his desire to continually find the state of the art and how it is—and should be—practiced today

I enjoyed tying the theory and practice together to attain a good understanding of the most recent applications

We received much assistance from our colleagues in the field Especially noted

on the title page are those who spent a great deal of time and effort providing critical input They provided a needed jolt for each author to finish the endeavor by their knowledge of the field, review of concepts, and critical editing when required

I would especially like to mention the assistance of a number of former students

at Manhattan College Richard Carbonaro scanned critical pictures while Rosanne Schirtzer, Clayton Conklin, Kevin Clarke and Sue Hildreth dug into the economics data from various agencies, a daunting task in itself John Gormley, Engineering Librarian at Manhattan, continually obtained needed references and ran critical interference allowing me to ignore due dates

The assistance of large municipal agencies in supplying critical information is acknowledged The New York City Department of Environmental Protection, NYCDEP (especially Robert Adamski, John Leonforte, James G Mueller (son), Hilary Einsohn, and Siobahn Rohan), coordinated efforts to obtain cost information

on the New York City plants The Metropolitan Water Reclamation District of Greater Chicago, MWRDGC (especially Hugh McMillan), provided the latest developments

on the Chicago side channel aeration systems The Middlesex County Utilities Authority, MCUA (especially Victor Santamarina), supplied insights into their high purity oxygen system upgrade

Most of all I would like to thank God for giving us the energy and insights to complete this book I look forward to it continuing to shed light on the profession and leading to the design and development of better aeration systems

The poem that follows was composed by Jim McKeown, a member of our original oxygen transfer standards committee, who died of cancer in the winter of 1990–1991 It gives a bit of the history of the standards work, supported by the USEPA and ASCE, that Bill and I were involved with since 1976 It is a reminder that our work should never get the best of us—not above our relationships with each other, and with our God

James A Mueller

To the Study of the Drop and the Bubble

James J McKeown This is a poor story about the dirty water band who took to the field when standardization was at hand After all, wasn’t it clear, although the data wasn’t “purty,” what was named the clean water test was really very dirty

The next step was upon us

it took only a spark of inspiration for our band to begin the search for the transfer of mass during respiration

So we left the mainstream, unfortunately, to no one’s real sorrow

to pursue our fair dream

in a breach where Whittier did Narrow The first results were so startling, every possible relationship linear,

we had to move east—to avoid the critique— our findings were true, but only in Califor-ni-a

Where we could test

to avoid bias oracle;

where wastewater was

by all standards, categorical

Who could argue with respiration, although lazy

extracted from sewage undergoing renovation

in New Jersey?

Convinced by such rationale supported by those seeking to prove that if things aren’t quite right once then they are always right when dual

We joined the band within site

of sometime energetic Indian Point where sometime aeration interfered with our living in an otherwise elegant joint

Although we did proudly stand, our bloom soon lost its peak when K La escaped us through an insidious leak

Suitably humbled, we moved on

to further learn that the non-steady test couldn’t be rushed when for nearly 20 minutes all in Ridgewood town, everyone, refused to flush

Let’s not forget good can come from bad for here in course bubbly, we examined off-gas And also, it can now be reported to superman’s value,

we corralled fair krypton here by switching from

plastic to glass

Undaunted we moved on to finale grand all planned to succeed where Miller had fallen now was the time to again make our stand

We would continue to search to stoop to lower ourselves to the depths where oxygen did lurk barely dissolved in such dirty water that we even enlisted one we called daughter—uh

clerk

But success was to come from more than mere traces

Rather, from working together with methods as different

as different as the looks on our faces Now, you think we were done, but an epilogue beckons

Because this band, as a group learned of martinis Cajun and riverboat soup, not to mention, the proper way to eat grapefruit But most important, to leave some work undone

so we could meet once more

to march to the cadence and the lure

in search of a sponsor to help us continue to work toward making dirty water—pure

March 23, 1984 ASCE Oxygen Transfer Standards Committee

Coronado, California

Table of Contents

Chapter 1 Introduction

1.1 Purpose

1.2 Intended Audience

1.3 Bibliography

Chapter 2 Principles

2.1 Mass Transfer Principles

2.2 Application to Oxygen Transfer

2.3 Design Equations

2.4 Nomenclature

2.5 Bibliography

Chapter 3 Diffused Aeration

3.1 Introduction

3.2 Description of Diffused Aeration Systems

3.3 Diffused Air System Layouts

3.4 Performance of Diffused Air Systems

3.5 Diffused Air System Design

3.6 Nomenclature

3.7 Bibliography

Chapter 4 Deep Tank Aeration with Blower and

Compressor Considerations

4.1 Introduction

4.2 Oxygen Transfer in Deep Tanks

4.3 Aeration Efficiency in Deep Tanks

4.4 Nomenclature

4.5 Bibliography

Chapter 5 Surface and Mechanical Aeration

5.1 Introduction

5.2 Low-Speed Surface Aerators

5.3 High-Speed or Motor Speed Aerators

5.4 Horizontal Rotors

5.5 Submerged Turbine Aerators

5.6 Aspirating Aerators

5.7 Factors Affecting Performance

5.8 Performance of Mechanical Aeration Devices

5.9 Design

5.10 Nomenclature

5.11 Bibliography

Chapter 6 High-Purity Oxygen Aeration

6.1 History

6.2 Covered Tank Systems

6.3 Open Tank Systems — Floating Cover

6.4 Nomenclature

6.5 Bibliography

Chapter 7 Testing and Measurement

7.1 Introduction

7.2 Aeration Tank Mass Balance

7.3 Clean Water Performance Testing

7.4 In-Process Oxygen Transfer Testing

7.5 Quality Assurance for Fine-Pore Diffusers

7.6 Characteristics of Diffused Air Materials

7.7 Nomenclature

7.8 Bibliography

Chapter 8 Aeration Systems in Natural Waters

8.1 Aeration — Streams and Rivers

8.2 Metropolitan Water District of Greater Chicago: Full-Scale Instream Aeration Systems

8.3 Nomenclature

8.4 Bibliography

Chapter 9 Operation and Maintenance

9.1 Operation

9.2 System Monitoring

9.3 Aeration System Control

9.4 Maintenance — Diffused Air

9.5 Maintenance — Mechanical Aeration

9.6 Nomenclature

9.7 Bibliography

1.1 PURPOSE 1.1.1 N EED AND G ROWTH IN F IELD

At the beginning of the 20th century, activated sludge systems were developed into

an economically viable secondary treatment method Aeration, used to transfer oxygen to the biologically active masses of organisms within these systems, has been an important part of wastewater treatment as the use of activated sludge proliferated in the field Significant changes have occurred in these systems as a result of not only advances in technology but also variations in the cost of energy required to operate them The driving force of economics in some instances has brought the technology used in older systems back to the forefront Due to the efficiency of power utilization, fine pore diffused aeration systems with full floor coverage have been rediscovered as an outstanding example of this technology Different types of aeration systems have been employed in the field, depending

on location and specific treatment requirements Large urban areas, where land is

at a premium, have tended to use high rate systems In contrast, areas that are more rural have used lower rate systems, generally requiring less operator involvement The requirements for increased nutrient removal and better effluent quality have fostered the growth of systems that now incorporate not only the typicalaerobic regions in aeration tanks, but the anaerobic and anoxic regions as well Thus, numerous types of activated sludge systems have been developed to incorporate these different demands These include deep tank aeration, high-purity oxygen, carousel or racetrack systems, anaerobic selector, and biological nutrient removal systems that attain nitrification and denitrification in different sections of the same tank The basic principles governing the transfer of oxygen into the aerobic portion

of these aeration systems are similar for all applications

The impact of aeration systems on plant capital and operating costs is one measure of the importance of this unit operation to wastewater treatment Table 1.1

summarizes the capital and operating costs of the aeration systems as a fraction of total plant costs These costs were obtained for a number of plants in the New York metropolitan area, as well as a plant in Seattle, Washington, and one in Darmstadt, Germany The date of the plant capital costs is given at substantial plant completion when secondary treatment is begun Many of the contracts are written on a multiyear basis, sometimes spanning 10 to 20 years, especially for the large New York plants being upgraded Construction of the Red Hook plant, a new facility, was begun in

1982 and completed in 1989 with secondary treatment on line in 1988

Based on Table 1.1, the capital costs for aeration systems are typically between

15 and 25 percent of the construction costs for the total treatment plant The exception to this statistic is the relatively low 5.57 percent aeration capital costs for

1

the North River plant in New York City This plant, located in upper Manhattan, has two additional major construction costs associated with it One is construction of the plant on piles over the Hudson River, and the other is the park constructed on top of the plant for use by local residents The costs of the Coney Island and Owls Head plants include a complete plant upgrade, during which the facility maintained operations This scenario is typically more costly than new plant construction Due

to the proximity of the local population, as in many New York plants, the Coney Island costs include covered tanks for all but the secondary clarifiers and a scrubber system to capture and treat air emissions before discharge

TABLE 1.1 Impact of Aeration Systems on Activated Sludge Treatment Plant Costs

Plant Name Location

Design Flow,

m 3 /s (MGD)

Type Aeration System

Capital Costs Yearly Operating Costs

Reference

Total Plant

10 6 $ (year)

% Due to Aeration

Total Plant

10 6 $/yr (year)

% Due to Aeration

Coney Island

Brooklyn, NY

4.4 (100)

Diffused, fine pore

650 (1990)

20 4.43 (1998) 4.05 (1999)

20.1–25.5 *

20.3–25.2 *

(Conklin, 2001)

North River

Manhattan, NY

7.5 (170)

Diffused, fine pore

968 (1986)

5.57 7.12

(1998) 7.43 (1999)

15.7 16.8

(Conklin, 2001; Leonforte, 1998) Red Hook Brooklyn,

NY

2.6 (60)

Diffused 232

(1988)

16.8 2.49

(1998) 2.29 (1999)

25 24

(Conklin, 2001; Leonforte, 1998) Owls

Head

Brooklyn, NY

5.3 (120)

Diffused 380

(1995)

27 7.15 (2000)

17 (Clarke,

2001) West

Point

Seattle, WA

5.8 (133)

High purity O 2

•surface

•4 stage

229 (1995)

19.3 (Hildreth,

1999; Hildreth, et al 1997) MCUA Sayreville,

NJ

6.5 (147)

HPO

•turbine

•surface

95.5 (1974) +8.9 (1995)

19.3

100 Upgrade

16.4 (1997) 15.2 (1999)

19.5 before 13 after upgrade

(Schirtzer, 2000)

Darmstadt Central

Germany 0.46

(10)

Diffused, fine tubes with propellers

•racetrack

95 (1995)

15 3.4 (1997)

11.4 (Poepel,

2001; Wacker, 1998)

* Including air scrubbers.