AWWA B300-2010 Hypochlorites《次氯酸盐》.pdf

1、ANSI/AWWA B300-10(Revision of ANSI/AWWA B300-04)AW WA StandardEffective date: April 1, 2010.First edition approved by AWWA Board of Directors June 2, 1953.This edition approved Jan. 17, 2010.Approved by American National Standards Institute Jan. 14, 2010.6666 West Quincy Avenue Advocacy Denver, CO 8

2、0235-3098 Communications T 800.926.7337 Conferences www.awwa.org Education and TrainingScience and TechnologySectionsThe Authoritative Resource on Safe WaterHypochloritesb300-10.indd i 3/8/2010 4:45:38 PMCopyright 2010 American Water Works Association. All Rights Reserved.iiAWWA StandardThis documen

3、t is an American Water Works Association (AWWA) standard. It is not a specifi cation. AWWA standards describe minimum requirements and do not contain all of the engineering and administrative information normally contained in specifi -cations. The AWWA standards usually contain options that must be

4、evaluated by the user of the standard. Until each optional feature is specifi ed by the user, the product or service is not fully defi ned. AWWA publication of a standard does not constitute endorsement of any product or product type, nor does AWWA test, certify, or approve any product. The use of A

5、WWA standards is entirely voluntary. This standard does not supersede or take precedence over or displace any applicable law, regulation, or codes of any governmental authority. AWWA standards are intended to represent a consensus of the water supply industry that the product described will provide

6、satisfactory service. When AWWA revises or withdraws this standard, an offi cial notice of action will be placed on the fi rst page of the classifi ed advertising section of Journal AWWA. The action becomes effective on the fi rst day of the month following the month of Journal AWWA publication of t

7、he offi cial notice.American National StandardAn American National Standard implies a consensus of those substantially concerned with its scope and provisions. An Ameri-can National Standard is intended as a guide to aid the manufacturer, the consumer, and the general public. The existence of an Ame

8、rican 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 National Standards are subject to periodic review, an

9、d 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 advertis-ing and promotional materials or on tags or labels that the goods are produced in conformity with particular A

10、merican 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 withdrawn at any time. ANSI procedures require that actio

11、n be taken to reaffi rm, revise, or withdraw this standard no later than fi ve years from the date of publication. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute, 25 West 43rd Street, Fourth F

12、loor, New York, NY 10036; (212) 642-4900, or e-mailing infoansi.org.All rights reserved. No part of this publication may be reproduced or 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 b

13、rief excerpts or quotations for review purposes, without the written permission of the publisher.Copyright 2010 by American Water Works AssociationPrinted in USAb300-10.indd Sec1:ii 3/8/2010 4:45:48 PMCopyright 2010 American Water Works Association. All Rights Reserved.iiiCommittee PersonnelTh e AWW

14、A Standards Committee on Disinfectants, which reviewed and approved this standard, had the following personnel at the time of approval:Cli ord L. McLain, ChairGeneral Interest MembersD.J. Gates, Citrus Heights, Calif. (AWWA)G. Giasson, Pawtucket Water Supply Board, Pawtucket, R.I. (AWWA)S.J. Posavec

15、,*Standards Group Liaison, AWWA, Denver, Colo. (AWWA)K.B. Stark, NSF International, Ann Arbor, Mich. (NSF)D.R. Wilkes,*Standards Council Liaison, Jordan Jones however, its practical solubility use is closer to 3 percent. Decanta-tion is advisable before use because of the excess insolubles present.

16、Storage in a cool, dry area is advisable, but storage periods should not exceed one year. Calcium hypo-chlorite can lose 3 percent to 10 percent available chlorine in one year. It is available in 3-lb to 5-lb (1.4-kg to 2.3-kg) cans, 2-lb to 9-lb (0.9-kg to 4.1-kg) plastic containers, and 100-lb (45

17、.4-kg) steel drums and in granular powder, granule, and tablet form. Solubility tests that determine both rate and percentage should be conducted with particular emphasis on testing the tablets. Approximately 1/8 lb/gal (15 g/L) of calcium hypochlorite to water produces a solution of approximately 1

18、 percent available chlorine.Sodium hypochlorite: 12 percent to 20 percent available chlorine. Other com-mon names for sodium hypochlorite are bleach, liquor, chlorine water, and Javelle water. Sodium hypochlorite will undergo some decomposition over time. Th ere are numerous parameters that a ect th

19、e rate of decomposition (see Th e Chlorine Insti-tute*Pamphlet 96, Sodium Hypochlorite Manual).* Th e Chlorine Institute Inc., 1300 Wilson Blvd., Arlington, VA 22209.b300-10.indd Sec1:vii 3/8/2010 4:45:49 PMCopyright 2010 American Water Works Association. All Rights Reserved.viiiSodium hypochlorite

20、is miscible in any proportion with water. It should be stored in a dark area where the temperature does not exceed 80F (30C). A 12 percent to 20 percent solution is still liquid at 0F (17.8C) but is a slush at 20F (28.9C). It is available in 5-gal and 13-gal (19-L and 49-L) carboys (glass or polyeth

21、ylene), 30-gal (113.6-L) drums, and in approximately 5,000-gal (18,926-L) tank trucks. Th e available chlorine content is as indicated in Table F.1.I.B. History. Th e original AWWA Standard for Hypochlorites, prepared for the AWWA Water Purifi cation Division, was approved by the Executive Committee

22、 of the Water Purifi cation Division and by the Water Works Practice Committee and received approval by the AWWA Board of Directors on June 2, 1953. It was designated ANSI/AWWA B300 53T.Th e initial document was rea rmed without revision on June 17, 1955, and the designation was changed from ANSI/AW

23、WA B300 53T to ANSI/AWWA B300 55. Subsequent revisions were adopted on June 5, 1964, Jan. 26, 1975, June 15, 1980, and June 14, 1987. Th is standard was revised by the AWWA Standards Committee on Disinfectants, and ANSI/AWWA B300-99 was approved by the AWWA Board of Directors on June 20, 1999. A sub

24、sequent revision was adopted on June 13, 2004. Th is edition was approved on Jan. 17, 2010.I.C. Acceptance. 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 sta

25、ndards and a certifi cation program for direct and indirect drinking water additives. Other members of the original consortium included the American Water Works Association Research Foundation (AwwaRF, now Table F.1 Chlorine available in sodium hypochloritegpl Available ChlorineTrade % Available Chl

26、orineChlorine Equivalentlb/galChlorine Equivalent kg/LGallons to Obtain 1 lb ChlorineLiters to Obtain 1 kg Chlorine200 20.0 1.630 0.200 00.610 005.000160 16.0 1.333 0.160 00.752 006.250150 15.0 1.200 0.150 00.800 006.667120 12.0 1.000 0.120 01.000 008.333050 05.0 0.417 0.050 02.400 020.000010 01.0 0

27、.083 0.010 12.000 100.000Sample Calculation:12 trade percent available chlorine = 120 grams per liter (gpl) available chlorine 120 gpl 3.785 L/gal 2.205 lb/1,000 g = 1 lb/gal available chlorineb300-10.indd Sec1:viii 3/8/2010 4:45:49 PMCopyright 2010 American Water Works Association. All Rights Reser

28、ved.ixWater Research Foundation) and the Conference of State Health and Environmental Managers (COSHEM). Th e American Water Works Association (AWWA) and the Association of State Drinking Water Administrators (ASDWA) joined later.In the United States, authority to regulate products for use in, or in

29、 contact with, drinking water rests with individual states.*Local agencies may choose to impose requirements more stringent than those required by the state. To evaluate the health e ects of products and drinking water additives from such products, state and local agencies may use various references

30、, including two standards developed under the direction of NSF, NSF/ANSI60, Drinking Water Treatment ChemicalsHealth E ects, and NSF/ANSI 61, Drinking Water System ComponentsHealth E ects.Various certifi cation organizations may be involved in certifying products in accor-dance with NSF/ANSI 60. Ind

31、ividual states or local agencies have authority to accept or accredit certifi cation organizations within their jurisdiction. Accreditation of certi-fi cation organizations may vary from jurisdiction to jurisdiction.Annex A, “Toxicology Review and Evaluation Procedures,” to NSF/ANSI 60 does not stip

32、ulate a maximum allowable level (MAL) of a contaminant for substances not regulated by a USEPA fi nal maximum contaminant level (MCL). Th e MALs of an unspecifi ed list of “unregulated contaminants” are based on toxicity testing guidelines (noncarcinogens) and risk characterization methodology (carc

33、inogens). Use of Annex A procedures may not always be identical, depending on the certifi er.ANSI/AWWA B300 addresses additives requirements in Sec. 4.4 of the standard. Th e transfer of contaminants from chemicals to processed water or the residual solids is becoming a problem of great concern. Th

34、e language in Sec. 4.4.2 is a recommenda-tion only for direct additives used in the treatment of potable water to be certifi ed by an accredited certifi cation organization in accordance with NSF/ANSI 60, Drinking Water Treatment ChemicalsHealth E ects. However, users of the standard may opt to make

35、 this certifi cation a requirement for the product. Users of this standard should also consult the appropriate state or local agency having jurisdiction in order to1. Determine additives requirements, including applicable standards.2. Determine the status of certifi cations by parties o ering to cer

36、tify products for contact with, or treatment of, drinking water.3. Determine current information on product certifi cation.* Persons outside the United States should contact the appropriate authority having jurisdiction. NSF International, 789 N. Dixboro Road, Ann Arbor, MI 48105. American National

37、Standards Institute, 25 West 43rd Street, Fourth Floor, New York, NY 10036.b300-10.indd Sec1:ix 3/8/2010 4:45:49 PMCopyright 2010 American Water Works Association. All Rights Reserved.xII. Special Issues.II.A. Storage and Handling Precautions. Light, heat, organic matter, and certain heavy metal cat

38、ions, such as copper, nickel, and cobalt, accelerate the decomposition of hypochlorites. Dampness appreciably decreases the life of metal containers in which the powdered forms are shipped. Hypochlorites should be stored in a cool, dry place, preferably in the dark or out of direct sunlight. Th ey a

39、re very active chemically and should be stored in a manner that prevents any possible contact with other materials that are fl ammable, such as oil, grease, glycerine, or printed matter. When removing hypochlorite from a drum, never use a scoop or vessel that is contaminated with organic matter.All

40、hypochlorite solutions are corrosive to some degree and will a ect the skin and eyes on contact. Any a ected areas should be washed with copious amounts of water. Personnel are advised to use caution and to wear protective clothing (i.e., gloves, apron, goggles, and a suitable vapor mask) when handl

41、ing the solutions. Personnel should refer to the manufacturers material safety data sheets (MSDS) for recommendations regarding personal protective equipment.Because chlorine gas can be released, never acidify a hypochlorite solution.Hypochlorite solutions can add chlorate/chlorite ions to the potab

42、le water. Th ere is some concern about the health e ects of chlorate/chlorite. Utilities using these prod-ucts are advised to analyze for the chlorate/chlorite ion in their water supply.Perchlorate is another possible contaminant in hypochlorites.II.B. Strength of Solutions. Th ere are several commo

43、n ways that the concentration of sodium hypochlorite may be expressed. Th ese are listed below with explanations.1. Available chlorine. Th e term available chlorine came into usage as a means of comparing oxidizers in di erent applications. Because chlorine was among the fi rst widely used oxidizers

44、, it became the standard against which other oxidizers were measured. As shown in the following equations, sodium hypochlorite is capable of oxidizing the same amount of iodide ion as the chlo-rine (Cl2) that it takes to manufacture the sodium hypochlorite.NaOCl + 2Kl + 2HAc I2+ NaCl + 2KAc + H2OTh

45、is may be compared with the reaction of chlorine with potassium iodide:Cl2+ 2Kl I2+ 2KClOne molecule of hypochlorite ion has the equivalent oxidizing power of two atoms (1 molecule) of chlorine. Th erefore, sodium hypochlorite behaves as if all of the chlorine b300-10.indd Sec1:x 3/8/2010 4:45:49 PM

46、Copyright 2010 American Water Works Association. All Rights Reserved.xiconsumed in making it is available for oxidizing purposes, even though half of that chlo-rine is in the chloride form.Available chlorine refers to the amount of chlorine equivalent to hypochlorite in terms of oxidizing power. It

47、is a measure of strength and bleaching power and, in one or another of its related units of measurement, denotes the concentration of the bleach solution.2. Grams per liter (gpl) available chlorine. Th e weight of available chlorine in grams contained in one liter of sodium hypochlorite solution.3.

48、Trade percent available chlorine. Commonly used to denote the strength of commercial sodium hypochlorite solutions, it is similar to grams per liter, except that the unit of volume is 100 milliliters instead of one liter. Its value is therefore one tenth of the grams per liter.trade percent availabl

49、e chlorine =gpl available chlorine(Eq 1)104. Weight percent available chlorine. Dividing trade percent by the specifi c gravity of the sodium hypochlorite solution gives weight percent or percent available chlorine by weight.wt % available chlorine =gpl available chlorine(Eq 2)10 (specifi c gravity of solution)wt % available chlorine =trade percent available chlorine(Eq 3)(specifi c gravity of solution)II.C. Sodium Hypochlorite. To facilitate a variety of calculations and operations in di erent chemical processes, it is often