1、American Society of Civil EngineersMeasurement of OxygenTransfer in Clean WaterThis document uses both the International System of Units (SI) and customary units.A S C E S T A N D A R DPublished by the American Society of Civil EngineersASCE/EWRI 2-06Measurement of oxygen transfer in clean water: AS
2、CE stan-dard, ASCE/SEI 2-06 / American Society of Civil Engineers.p. cm.Includes bibliographical references.ISBN-13: 978-0-7844-0848-3ISBN-10: 0-7844-0848-31. WaterAerationMeasurementStandards.2. WaterDissolved oxygenMeasurementStandards. I. American Society of Civil Engineers.TD458.M42 2007628.1650
3、218dc222006102612Published by American Society of Civil Engineers1801 Alexander Bell DriveReston, Virginia 20191www.pubs.asce.orgAny statements expressed in these materials are those of the individual authors and do not necessarily represent theviews of ASCE, which takes no responsibility for any st
4、ate-ment made herein. No reference made in this publication toany specific method, product, process, or service constitutesor implies an endorsement, recommendation, or warrantythereof by ASCE. The materials are for general informationonly; they are not intended as a reference in purchase ofspecific
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8、equests for 100 copies or moreshould be submitted to the Reprints Department, PublicationsDivision, ASCE (address above); email: permissionsasce.org. A reprint order form can be found atwww.pubs.asce.org/authors/reprints.html.Copyright 2007 by the American Society of Civil Engineers.All Rights Reser
9、ved.ISBN 13: 978-0-7844-0848-3ISBN 10: 0-7844-0848-3Manufactured in the United States of America.Library of Congress Cataloging-in-Publication DataSTANDARDSIn 2003, the Board of Direction approved the revision tothe ASCE Rules for Standards Committees to govern thewriting and maintenance of standard
10、s developed by theSociety. All such standards are developed by a consensusstandards process managed by the Societys Codes andStandards Committee (CSC). The consensus processincludes balloting by a balanced standards committeemade up of Society members and nonmembers, ballotingby the membership of th
11、e Society as a whole, and ballot-ing by the public. All standards are updated or reaffirmedby the same process at intervals not exceeding five years.The following standards have been issued:ANSI/ASCE 1-82 N-725 Guideline for Design andAnalysis of Nuclear Safety Related Earth StructuresASCE/EWRI 2-06
12、 Measurement of Oxygen Transfer inClean WaterANSI/ASCE 3-91 Standard for the Structural Design ofComposite Slabs and ANSI/ASCE 9-91 StandardPractice for the Construction and Inspection ofComposite SlabsASCE 4-98 Seismic Analysis of Safety-Related NuclearStructuresBuilding Code Requirements for Mason
13、ry Structures(ACI 530-02/ASCE 5-02/TMS 402-02) andSpecifications for Masonry Structures (ACI 530.1-02/ASCE 6-02/TMS 602-02)ASCE/SEI 7-05 Minimum Design Loads for Buildingsand Other StructuresSEI/ASCE 8-02 Standard Specification for the Design ofCold-Formed Stainless Steel Structural MembersANSI/ASCE
14、 9-91 listed with ASCE 3-91ASCE 10-97 Design of Latticed Steel TransmissionStructuresSEI/ASCE 11-99 Guideline for Structural ConditionAssessment of Existing BuildingsASCE/EWRI 12-05 Guideline for the Design of UrbanSubsurface DrainageASCE/EWRI 13-05 Standard Guidelines for Installationof Urban Subsu
15、rface DrainageASCE/EWRI 14-05 Standard Guidelines for Operationand Maintenance of Urban Subsurface DrainageASCE 15-98 Standard Practice for Direct Design ofBuried Precast Concrete Pipe Using StandardInstallations (SIDD)ASCE 16-95 Standard for Load Resistance Factor Design(LRFD) of Engineered Wood Co
16、nstructionASCE 17-96 Air-Supported StructuresASCE 18-96 Standard Guidelines for In-Process OxygenTransfer TestingASCE 19-96 Structural Applications of Steel Cables forBuildingsASCE 20-96 Standard Guidelines for the Design andInstallation of Pile FoundationsANSI/ASCE/TC*H11009H33527 determination poi
17、nt value of the steady-state DO saturation concentration as timeapproaches infinity, mLH110023;C0H33527 DO concentration at time zero, mLH110023;KLa H33527 determination point value of the apparent volumetric mass transfer coefficient, tH110021,defined so thatKLa H33527 rate of mass transfer per uni
18、t volumeH20862(C*H11009H11002 C).Throughout this standard, the terminology for unitswill be shown as follows: m H33527 mass units, l H33527 lengthunits, f H33527 force units, and t H33527 time units.Nonlinear regression is employed to fit Eq. (2-1)to the DO profile measured at each determinationpoin
19、t during reoxygenation. In this way, estimates ofKLa and C*H11009are obtained at each determination point.These estimates are adjusted to standard conditions,and the standard oxygen transfer rate (mass of oxygen dissolved per unit time at a hypothetical concentration of zero DO) is obtained as the a
20、ver-age of the products of the adjusted determination point KLa values, the corresponding adjusted determi-nation point C*H11009values, and the tank volume. Recentdevelopments that have the potential to be recognizedin a future edition of this standard appear inCommentary A.3.0 SIGNIFICANCE AND LIMI
21、TATIONSOxygen transfer rate measurements are useful for comparing the performance and energy efficiencyof oxygenation devices operating in clean water.However, performance of these devices in processwater may significantly differ from the performance inclean water, and the amount of difference will
22、dependon the device, on how it is applied, and on the natureof the process water.1Measurement of Oxygen Transfer in Clean WaterAgreement of this method has been evaluated byparallel testing with the radioactive tracer strippingmethod, and KLa by the two methods has been foundto be within H110063% (R
23、ef. 6).4.0 DEFINITIONS AND NOMENCLATURE4.1 OXYGEN TRANSFER RATEMass of oxygen per unit time dissolved in a vol-ume of water by an oxygen transfer system operatingunder given conditions of temperature, barometricpressure, power, gas rate, and dissolved oxygen concentration.4.2 STANDARD OXYGEN TRANSFE
24、R RATEOTR in clean water when the DO concentration iszero at all points in the water volume, the water tem-perature is 20H11034C, and the barometric pressure is1.00 atm (101.3 kPa) (see Eq. 8-3).4.3 AERATION EFFICIENCYOTR per unit total power input. Power input maybe based on either delivered brake
25、or wire power, andthis basis must be stated.4.4 STANDARD AERATION EFFICIENCY SOTR per unit total power input. Power inputmay be based on delivered, brake, or wire power, andthis basis must be stated.4.5 OXYGEN TRANSFER EFFICIENCYFraction of oxygen in an injected gas stream dis-solved under given con
26、ditions of temperature, baro-metric pressure, gas rate, and DO concentration.4.6 STANDARD OXYGEN TRANSFEREFFICIENCYOTE in clean water when the DO concentration is zero at all points in the water volume, the waterMEASUREMENT OF OXYGEN TRANSFER IN CLEAN WATERtemperature is 20H11034C, and the barometri
27、c pressure is1.00 atm (101.3 kPa).5.0 APPARATUS AND METHODS5.1 TANKThe geometry and tank size will depend on theparticular oxygenation system to be tested. The test isapplicable to tank volumes that may range from smalllaboratory vessels of a few liters to large tanks over1 million gallons (3,800 m3
28、).5.2 WATERFor determination of a standard oxygen transferrate, the water to which oxygen is transferred shouldbe equivalent in quality to a potable public water sup-ply. Further specifications of clean water are given inSection 6.3.The unsteady-state clean water test is occasionallyconducted in cle
29、an water with detergent addition in aneffort to mask the effect of trace contaminants in tapwater or to roughly simulate transfer in municipalwastewater.5.3 OXYGENATION DEVICEThis method is applicable to a wide variety ofoxygenation devices installed in the tank including,but not limited to, the fol
30、lowing:Surface Aerators: high-speed, low-speed, andhorizontal shaft rotors.Subsurface Oxygenation Devices: diffused air, static tubes, submerged turbines, and jet aerators.5.4 SAMPLING DEVICESSubmersible pumps and tubing are necessarywhen DO concentrations are to be measured onpumped samples in acco
31、rdance with Section 6.8.2.They are also recommended to obtain samples forWinkler calibration of DO probes used in situ andsamples for water chemistry analysis.25.5 DISSOLVED OXYGEN MEASUREMENT5.5.1 Wet chemical measurement of DO on pumpedsamples shall be in accordance with the azide modifi-cation of
32、 the Winkler method described inSection 4500-OC of the 20th Edition of StandardMethods (Ref. 7).5.5.2 Membrane electrode measurement of DO, eitheron pumped samples or in situ, shall be in accordancewith Section 4500-OG of Standard Methods (Ref. 7;see also Section 6.9.1).5.6 TEMPERATURE MEASUREMENTWa
33、ter temperature measurement shall be in accor-dance with Section 2550 of Standard Methods(Ref. 7).5.7 DEOXYGENATION CHEMICALS5.7.1 Sodium SulfiteEither reagent- or technical-grade sodium sulfite(Na2SO3) shall be used for deoxygenation in accor-dance with Section 6.7. It is preferable that the sodium
34、sulfite be free of cobalt. However, a chemical contain-ing a known concentration of cobalt may be employed,provided that this cobalt is considered as part of thetotal cobalt addition discussed in Section 6.7.1.5.7.2 Cobalt CatalystEither reagent-grade or technical-grade cobaltchloride hydrate, CoCl2
35、6H2O, or cobalt sulfate,CoSO4, shall be used to catalyze the deoxygenationreaction in accordance with Section 6.7.5.8 COMPUTER OR CALCULATORA computer or programmable calculator capableof handling the recommended methods of parameterestimation described in Section 7.2 is required.5.9 GAS FLOW MEASUR
36、EMENT APPARATUS For oxygenation systems based on subsurface gas injection, an apparatus capable of measuring the H11080gas flow with an accuracy of H110065% in accordance withAnnex A is required.5.10 POWER MEASUREMENT APPARATUSThe apparatus required for power measurementswill depend on the specific
37、oxygenation device, but, ingeneral, an apparatus suitable for measurement of totaldelivered power and total wire power in accordancewith Annex B is required.6.0 PROCEDURE6.1 ADVANCE PREPARATION ANDRESPONSIBILITIESWhen this method is to be applied, the engineer-owner-manufacturer (EOM) representative
38、s shall agreein advance on the specific system to be tested and thetest conditions. The items upon which agreement mustbe reached include1. test location (field installation or shop tank),2. tank size and geometry,3. aerator placement,4. aerator power and gas rates,5. temperature correction factor,
39、H9258 if different from1.024,6. method of sealing partition walls, if used, and testprocedures and tolerances acceptable for deter-mining sealing effectiveness,7. source and characteristics of test water includingtotal dissolved solids concentration (TDS) andconductivity,8. sodium sulfite addition p
40、rocedure,9. water temperature range, if different from1030H11034C, and10. DO measurement method and locations.Where field testing is to be conducted, the engineer-owner representative should provide the manufacturer with detailed drawings and speci-fications of the tank or tank section in which the
41、testwill be conducted. Information on the water supplysource and available water chemistry data should beprovided. Water samples should be made available tothe manufacturer for laboratory experiments regardingthe chemical additions that will be made.Once the installation of aeration equipment iscomp
42、leted, provision should be made for EOM repre-sentatives to inspect the installation to verify place-ment and testing conditions. Systems employing ASCE/EWRI 2-063diffused air aeration should be tested to eliminateleaks. Provisions for power and airflow measurementshould be verified and modification
43、s made as needed.It may be necessary to install equipment such asmeters for power measurement, supplemental air pip-ing, orifice plates, and manometers, as described inAnnexes A and B.Upon completion of the installation of the aera-tion equipment, the test tank should be cleaned priorto filling for
44、testing. Once the tank is filled with thetest water, chemical and biological contaminationshould be avoided. It may be necessary to dewater andrefill the test tank during the testing, and adequatepumping and discharge arrangements should be made.6.2 TEST TANK GEOMETRY AND AERATORPLACEMENTIt is diffi
45、cult to describe a required geometry orplacement for testing conducted in tanks other than thefull-scale field facility (Ref. 8). Appropriate configu-rations for shop tests should simulate the field condi-tions as closely as possible. For example, water depthsshould be similar, if not identical, and
46、, for certain sys-tems, width-to-depth or length-to-width ratios shouldbe similar. Potential interference resulting from walleffects and any extraneous piping or other materials inthe tank should be minimized. The density of the aera-tor placement, air flow per unit volume, or area andpower input pe
47、r unit volume are examples of parame-ters that can be used to assist in making comparativeevaluations.Testing of tank sections is also useful in certainsituations (e.g., long narrow diffused aeration tanks)where there is little water circulation between the adjacent sections. In this approach, a tan
48、k is dividedinto sections, and each section is tested individually.When this testing is performed, sealed partitions shallbe installed between adjacent sections to prevent interchange of oxygen by advection and diffusion.This technique can provide information on spatialvariation of KLa and SOTR in t
49、anks designed fortapered aeration.Consideration should be given to utilization ofshop testing or testing of tank sections when full-scalefacilities are very large (e.g., in excess of 1 milliongallons) (3,800 m3). Other criteria to be considered in making this judgment are1. ease of distribution of deoxygenation chemicals(distribution may be difficult in certain tanks),2. sampling requirements (very large tanks may bedifficult to sample adequately), andMEASUREMENT OF OXYGEN TRANSFER IN CLEAN WATER3. bulk flow and mixing patterns (shop or section test-ing should not be d
