1、ANSI/AWWA B303-18(Revision of ANSI/AWWA B303-10)AWWA StandardSMSodium ChloriteEffective date: May 1, 2018.First edition approved by AWWA Board of Directors June 1, 1967.This edition approved Jan. 20, 2018.Approved by American National Standards Institute Nov. 20, 2017.Copyright 2018 American Water W
2、orks Association. All Rights Reserved. iiAWWA StandardThis document is an American Water Works Association (AWWA) standard. It is not a specification. AWWA standards describe minimum requirements and do not contain all of the engineering and administrative information normally contained in specifica
3、tions. The AWWA standards usually contain options that must be evaluated by the user of the standard. Until each optional feature is specified by the user, the product or service is not fully defined. AWWA publication of a standard does not constitute endorsement of any product or product type, nor
4、does AWWA test, certify, or approve any product. The use of AWWA standards is entirely voluntary. This standard does not supersede or take precedence over or displace any applicable law, regulation, or code of any governmental authority. AWWA standards are intended to represent a consensus of the wa
5、ter industry that the product described will provide satisfactory service. When AWWA revises or withdraws this standard, an official notice of action will be placed in the Official Notice section of Journal - American Water Works Association. The action becomes effective on the first day of the mont
6、h following the month of Journal AWWA publication of the official notice.American National StandardAn American National Standard implies a consensus of those substantially concerned with its scope and provisions. An American National Standard is intended as a guide to aid the manufacturer, the consu
7、mer, and the general public. The existence of an American National Standard does not in any respect preclude anyone, whether that person has approved the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standard. American N
8、ational Standards are subject to periodic review, and users are cautioned to obtain the latest editions. Producers of goods made in conformity with an American National Standard are encouraged to state on their own responsibility in advertising and promotional materials or on tags or labels that the
9、 goods are produced in conformity with particular American National Standards.Caution notiCe: The American National Standards Institute (ANSI) approval date on the front cover of this standard indicates completion of the ANSI approval process. This American National Standard may be revised or withdr
10、awn at any time. ANSI procedures require that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of ANSI approval. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National
11、 Standards Institute, 25 West 43rd Street, Fourth Floor, New York, NY 10036; 212.642.4900; or emailing infoansi.org.ISBN-13, print: 978-1-62576-285-6 eISBN-13, electronic: 978-1-61300-466-1DOI: http:/dx.doi.org/10.12999/AWWA.B303.18All rights reserved. No part of this publication may be reproduced o
12、r transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information or retrieval system, except in the form of brief excerpts or quotations for review purposes, without the written permission of the publisher.Copyright 2018 by American Water Works
13、Association Printed in USACopyright 2018 American Water Works Association. All Rights Reserved. iiiCommittee PersonnelThe AWWA Standards Committee on Disinfectants, which developed and approved this standard, had the following personnel at the time of approval:K. Blake Stark, ChairGeneral Interest M
14、embersK.-K. Au, FMC Global Peroxygens, Naperville, Ill.N.J. Edman,*Standards Group Liaison, Denver, Colo.M.C. Graves, Freese and Nichols Inc., Austin, TexasR. Hampaul, Indigenous and Northern Affairs Canada, Vancouver, B.C., CanadaS.J. Posavec,*Standards Group Liaison, AWWA, Denver, Colo.G. Ramon,*S
15、tandards Council Liaison, Little Rock Wastewater, Little Rock, Ark.M. Sivaganesan, USEPA, Cincinnati, OhioK.B. Stark, NSF International, Ann Arbor, Mich.A. Waldron, CH2M, Englewood, Colo.Producer MembersM.C. Gibson, American Chemistry Council, Washington, D.C.R. Ness, Olin Chlor Alkali Products, Cha
16、rleston, Tenn.D.S. Weatherup, De Nora Water Technologies, Colmar, Pa.User MembersR.C. Lorenz, Westerville Water Plant, Westerville, OhioC.L. McLain, Consultant, Moorhead, Minn.F. Noce, Cleveland Water, Strongsville, OhioL. Olson, American Water, Voorhees, N.J.P.R. Riendeau, New England Water Works A
17、ssociation, Holliston, Mass.* Liaison, nonvotingCopyright 2018 American Water Works Association. All Rights Reserved. This page intentionally blank.vForewordI Introduction. . viiI.A Background . viiI.B History viiiI.C Acceptance viiiII Special Issues. ixII.A Handling, Storage, and SafetyPrecautions
18、ixIII Use of This Standard . xiIII.A Purchaser Options and Alternatives xiIII.B Modification to Standard xiIV Major Revisions . xiV Comments xiStandard1 General1.1 Scope. 11.2 Purpose . 11.3 Application 12 References 23 Definitions . 24 Requirements4.1 Physical Requirements . 34.2 Chemical Requireme
19、nts 34.3 Impurities 45 Verification5.1 Sampling . 45.2 Test ProceduresGeneral . 65.3 Test Procedures for Sodium Chlorite, Iodometric Method . 65.4 Test Procedure for Sodium Hydroxide . 75.5 Test Procedure for Sodium Carbonate . 85.6 Test Procedure for Sodium Chloride . 85.7 Test Procedure for Sodium
20、 Sulfate . 95.8 Test Procedure for Arsenic . 105.9 Test Procedure for Sodium Nitrate 105.10 Test Procedure for Sodium Chlorate . 105.11 Test Procedure for Sodium ChlorateAlternative Method . 125.12 Notice of Nonconformance . 126 Delivery6.1 Marking 136.2 Packaging and Shipping 136.3 Affidavit of Com
21、pliance 14Figure1 Crystallization Temperature of Sodium Chlorite Solutions . 3ContentsAll AWWA standards follow the general format indicated subsequently. Some variations from this format may be found in a particular standard.SEC. PAGE SEC. PAGECopyright 2018 American Water Works Association. All Ri
22、ghts Reserved. This page intentionally blank.viiForewordThis Foreword is for information only and is not a part of ANSI*/AWWA B303.I. Introduction.I.A. Background. Sodium chlorite, NaClO2, is made by the partial reductionof sodium chlorate to chlorine dioxide and the chlorine dioxides subsequent con
23、version to sodium chlorite in an alkaline solution in the presence of hydrogen peroxide. An excess of both peroxide and caustic is present to ensure complete reaction as follows:2222222222ClOHONaOHNaClO HO O+ +Under unfavorable conditions, ClO2is also known to dissociate to chlorite and chlorate as
24、follows:ClOOHClO ClOHO22322+Any chlorine present would be in the hypochlorite form because of the strong alkaline conditions. Any chlorate ion so formed is recycled through the process to optimize recovery of sodium chlorite. Hypochlorite will react with hydrogen peroxide to yield chloride as follow
25、s:OClHOClOHO+22 22Because there is no source of ammonia or nitrogen in the process, chloramines will not be present as an impurity.Sodium chlorite is a dry flaked salt, which, because of its powerful oxidizing nature, is shipped in steel drums bearing Department of Transportation (DOT) yellow (Class
26、 5.1) oxidizer labels. Dry flaked material is formulated by mixing sodium chlorite solutions with stabilizing salts in solution prior to either drying or filtering. The drying or filtering may be coincidental with spraying under atomizing conditions to achieve particle uniformity for flaking charact
27、eristics. As marketed in the solid form, sodium chlorite contains approximately 80 percent by weight sodium chlorite; in the aqueous form, it contains approximately 40 percent or less by weight sodium chlorite. Technical sodium chlorite is a white flaked salt with a density of approximately 56 lb/ft
28、3(0.90 g/cc). Some material may have a tint of orange, depending on the iron content. Sodium chlorite is stable when sealed or in solution but can ignite in the presence of * American National Standards Institute, 25 West 43rd Street, Fourth Floor, New York, NY 10036.Copyright 2018 American Water Wo
29、rks Association. All Rights Reserved. viiiorganic materials. For this reason, the solution should not be allowed to dry out on floors but should be hosed down with minimum splashing.Sodium chlorite dissolves easily in water at ordinary temperatures to form a pale-yellow solution. This solution is ch
30、emically stable under ordinary temperature and pressure conditions. Solutions above 2530 percent weight per weight (w/w) may crystallize at moderate ambient temperatures. Crystallization temperatures may vary because of solutions originating from dilution of either slurried or dried materials.Sodium
31、 chlorite used for the onsite production of chlorine dioxide for use as a disinfectant in the treatment of drinking water or for pesticidal use in processing plant-flume water, sewage treatment, slime control in paper mills, and bacteria control in oil wells requires US Environmental Protection Agen
32、cy (USEPA) registration as well as registration in the state in which it is used. Sodium chlorite to be sold and used for drinking water treatment must be registered under a label or labels indicating these uses.I.B. History. The original ANSI/AWWA Standard for Sodium Chlorite wasprepared by Committ
33、ee 7440P. The standard was approved as tentative on Jan. 25, 1965, and made a standard by the AWWA Board of Directors on June 1, 1967. The standard was designated ANSI/AWWA B303-67.The AWWA Standards Committee on Chlorine, Chlorine Compounds, and Related Alkalies prepared the 1988 edition, which was
34、 approved on June 19, 1988. The AWWA Standards Committee on Disinfectants prepared the 1995 edition, which was approved on June 17, 1995. Subsequent revisions of ANSI/AWWA B303 were approved on June 11, 2000, Jan. 16, 2005, and on June 20, 2010. This edition was approved on Jan. 20, 2018.I.C. Accept
35、ance. In May 1985, the US Environmental Protection Agency(USEPA) entered into a cooperative agreement with a consortium led by NSF International (NSF) to develop voluntary third-party consensus standards and a certification program for direct and indirect drinking water additives. Other members of t
36、he original consortium included the Water Research Foundation (formerly AwwaRF) and the Conference of State Health and Environmental Managers (COSHEM). The American Water Works Association (AWWA) and the Association of State Drinking Water Administrators (ASDWA) joined later.In the United States, au
37、thority to regulate products for use in, or in contact with, drinking water rests with individual states.*Local agencies may choose to impose * Persons outside the United States should contact the appropriate authority having jurisdiction.Copyright 2018 American Water Works Association. All Rights R
38、eserved. ixrequirements more stringent than those required by the state. To evaluate the health effects of products and drinking water additives from such products, state and local agencies may use various references, including two standards developed under the direction of NSF:*NSF/ANSI 60, Drinkin
39、g Water Treatment ChemicalsHealth Effects, and NSF/ANSI 61, Drinking Water System ComponentsHealth Effects.Various certification organizations may be involved in certifying products in accordance with NSF/ANSI 60. Individual states or local agencies have authority to accept or accredit certification
40、 organizations within their jurisdictions. Accreditation of certification organizations may vary from jurisdiction to jurisdiction.Annex A, “Toxicology Review and Evaluation Procedures,” to NSF/ANSI 60 does not stipulate a maximum allowable level (MAL) of a contaminant for substances not regulated b
41、y a USEPA final maximum contaminant level (MCL). The MALs of an unspecified list of “unregulated contaminants” are based on toxicity testing guidelines (noncarcinogens) and risk characterization methodology (carcinogens). Use of Annex A procedures may not always be identical, depending on the certif
42、ier.ANSI/AWWA B303 addresses additives requirements in Sec. 4.3.3 of the standard. The transfer of contaminants from chemicals to processed water or to residual solids is becoming a problem of greater concern. The language in Sec. 4.3.3 is a recommendation only for direct additives used in the treat
43、ment of potable water to be certified by an accredited certification organization in accordance with NSF/ANSI 60, Drinking Water Treatment ChemicalsHealth Effects. However, users of the standard may opt to make this certification a requirement for the product. Users of this standard should also cons
44、ult the appropriate state or local agency having jurisdiction in order to1. Determine additives requirements, including applicable standards.2. Determine the status of certifications by parties offering to certify productsfor contact with, or treatment of, drinking water.3. Determine current informa
45、tion on product certification.II. Special Issues.II.A. Handling, Storage, and Safety Precautions. Aqueous sodium chloritesolution is shipped in stainless-steel and fiberglass tank trucks according to US Department of Transportation (DOT) regulations. The temperature in the tanks is maintained to avo
46、id crystallization. On receipt, the purchaser should dilute the solution appropriately to prevent the crystallization of sodium chlorite. As received in loose-flake form in metal containers, sodium chlorite will tolerate some rough handling.* NSF International, 789 North Dixboro Road, Ann Arbor, MI
47、48105.Copyright 2018 American Water Works Association. All Rights Reserved. xSodium chlorite in contact with acid will react with rapid evolution of chlorine dioxide gas. When heated above 347F (175C), dry sodium chlorite will decompose rapidly, liberating oxygen, with the evolution of sufficient heat to make the decomposition self-sustaining. If the decomposition of sodium chlorite is contained, as in closed containers, the effect is explosive. Therefore, sodium chlorite should be protected at all times from exposure to heat. In case of ignition, normal firefighting equipment is relatively
