1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-21420-3 SANS 51278:2008Edition 1EN 1278:1998Edition 1SOUTH AFRICAN NATIONAL STANDARD Chemicals used for treatment of water intended for hu
4、man consumption Ozone This national standard is the identical implementation of EN 1278:1998 and is adopted with the permission of CEN, rue de Stassart 36, B-1050 Brussels. Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344
5、1568 international code + 27 12 www.stansa.co.za Standards South Africa SANS 51278:2008 Edition 1 EN 1278:1998 Edition 1 Table of changes Change No. Date Scope National foreword This South African standard was approved by National Committee StanSA TC 5140.19, Water, in accordance with procedures of
6、Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. This SANS document was published in April 2008. EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 1278September 1998ICS 71.100.80Descriptors: potable water, water treatment, chemical products, ozone, description, physical p
7、roperties, chemicalproperties, impurities, toxic substances, tests, labelling, storageEnglish versionChemicals used for treatment of water intended for humanconsumption - OzoneProduits chimiques utiliss pour le traitement de leaudestine la consommation humaine - OzoneProdukte zur Aufbereitung von Wa
8、sser fr denmenschlichen Gebrauch - OzonThis European Standard was approved by CEN on 5 September 1998.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up
9、-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder
10、the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Iceland, Ireland, Italy, Luxembour
11、g, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGCentral Secretariat: rue de Stassart, 36 B-1050 Brussels 1998 CEN All rights of exploitation in any form and by any means
12、reservedworldwide for CEN national Members.Ref. No. EN 1278:1998 ESANS 51278:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .Page 2EN 1278:1998ContentsForeword 3Introduction 41 Scope 42 Normative reference. 43 Description 43.1 Identificat
13、ion . 43.2 Commercial form 53.3 Physical properties .53.4 Chemical properties 74 Purity criteria 84.1 Composition of commercial product 84.2 Impurities and main by-products. 84.3 Toxic substances85 Test methods 85.1 Sampling 85.2 Analyses. 96 Labelling - Transportation - Storage. 126.1 Means deliver
14、y . 126.2 Stability. 12Annex A (informative) General information on ozone 13Annex B (normative) General rules relating to safety 20Annex C (informative) Bibliography 21SANS 51278:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .Page 3EN 12
15、78:1998ForewordThis European Standard has been prepared by Technical Committee CEN/TC 164 “Water supply“,the secretariat of which is held by AFNOR.This European Standard shall be given the status of a national standard, either by publication ofan identical text or by endorsement, at the latest by Ma
16、rch 1999, and conflicting national standardsshall be withdrawn at the latest by March 1999.According to the CEN/CENELEC Internal Regulations, the national standards organizations of thefollowing countries are bound to implement this European Standard: Austria, Belgium, CzechRepublic, Denmark, Finlan
17、d, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg,Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.SANS 51278:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .Page 4EN 1278:1998IntroductionIn r
18、espect of potential adverse effects on the quality of water intended for human consumption,caused by the product covered by this Standard :1) this Standard provides no information as to whether the product may be used withoutrestriction in any of the Member States of the EU or EFTA ;2) it should be
19、noted that, while awaiting the adoption of veritable European criteria, existingnational regulations concerning the use and/or the characteristics of this product remain inforce.1 ScopeThis European Standard is applicable to ozone used for treatment of water intended for humanconsumption. It describ
20、es the characteristics of ozone and specifies the requirements and thecorresponding test methods for ozone. It gives information on its use in water treatment.2 Normative referenceThis European standard incorporates by dated and undated reference, provisions from otherpublications. These normative r
21、eferences are cited at the appropriate place in the text and thepublications are listed hereafter. For dated references, subsequent amendments to or revisions ofany of these publications apply to this European standard only when incorporated in it byamendment or revision. For undated references the
22、latest edition of the publication referred toapplies.EN ISO 3696 Water for analytical laboratory use - Specification and test method(ISO 3696:1987)3 Description3.1 Identification3.1.1 Chemical nameOzone.3.1.2 Synonym or common nameNone (has sometimes been called improperly “allotropic oxygen“).3.1.3
23、 Relative molecular mass48.SANS 51278:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .Page 5EN 1278:19983.1.4 Empirical formulaO3.3.1.5 Chemical formulaO3.3.1.6 CAS Registry Number 1)10028-15-6.3.1.7 EINECS reference 2)Not applicable.3.2
24、Commercial formOzone is generated on or near the site of use.3.3 Physical properties3.3.1 AppearanceBluish gas,the liquid is dark blue.NOTE : A weak absorption in the visual range between 435 nm and 475 nm.3.3.2 DensityGas : 2,144 kg/m3at NTP (Normal Temperature Pressure, 273 K and 101,3 kPa) ;Liqui
25、d : 1,574 g/ml at - 183 C ;Solid : 1,728 g/cm3.3.3.3 Solubility in waterIn pure water, the solubility values (S) expressed in grams per cubic meter water per (grams percubic meter) gas at 101,3 kPa are given in table 1.1)Chemical Abstracts Service Registry Number2) European Inventory of Existing Com
26、mercial Chemical SubstancesSANS 51278:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .Page 6EN 1278:1998Table 1 : Solubility in waterTemperatureof waterCSolubilityS, in gmHOg m gas/3230 0,645 0,510 0,3915 0,3120 0,2425 0,1930 0,1535 0,12N
27、OTE 1 : Recent surveys of literature data are given in Bibliography. See C.2, C.3 and C.4.NOTE 2 : S is a ratio, not an absolute concentration.3.3.4 Vapour pressureThe vapour pressure of ozone depending on temperature is given in table 2.Table 2 : Vapour pressureTemperature Vapour pressureC kPa- 183
28、 0,0147- 180 0,028- 170 0,188- 160 0,897- 150 3,306- 140 9,892- 130 25,331- 120 56,928- 110 115,322- 1002 139,0793.3.5 Boiling point at 100 kPa 3)- 112 C.NOTE : Vaporization heat : 681 kJ/m3at NTP.3) 100 kPa = 1 barSANS 51278:2008This s tandard may only be used and printed by approved subscription a
29、nd freemailing clients of the SABS .Page 7EN 1278:19983.3.6 Melting point- 196 C.3.3.7 Specific heat (liquid)Not applicable.3.3.8 Viscosity (dynamic)0,004 2 Pa.s at - 195 C ;0,0015 5 Pa.s at - 183 C.3.3.9 Critical temperature- 12,1 C.3.3.10 Critical pressure5 460 kPa.3.3.11 Physical hardnessNot appl
30、icable.3.4 Chemical propertiesOzone is a powerful oxidant. The standard redox potentials (25 C) are :(EoH-values in volts) :O3+ 2H+ 2e-O2+ H2O EoH= 2,07 V (1)O3+ H2O + 2e-O2+ 2OH-EoH= 1,24 V (2)OH + H+ e-H2O EoH= 2,42 V(calculated value) (3)If the pH increases by one unit, the EH -values shall decre
31、ase by 30 mV per electron transferred.At 100 kPa and 25 C and pH = 7 the EH-values, versus the normal hydrogen electrode, become:O3(1) = 1,66 V ;O3(2) = 0,82 V ;SANS 51278:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .Page 8EN 1278:1998
32、OH(3) = 2,21V.In water treatment most of the direct reactions of ozone are dipolar cyclo-additions andelectrophilic substitution reactions. Moreover ozone, in water, can generate radicals such as OH :(O3 + H2O 2 OH + O2). The OH radical is a strong general oxidant.4 Purity criteria4.1 Composition of
33、 commercial productOzone is obtainable in air, oxygen or air enriched in oxygen.Typical concentrations obtainable in air are in the range of 15 g/m3to 45 g/m3(NTP) and, inoxygen 40 g/m3to 200 g/m3(NTP).The concentration (in grams per cubic meter NTP) at the nominal operating condition of thegenerato
34、rs shall be specified in the tendering documents.4.2 Impurities and main by-productsSee A.3.2.4.3 Toxic substancesNOTE : For the purpose of this standard “toxic substances“ are those defined in the EUDirective 80/778/EEC of 15 July , 1980 (see C.1).None of the toxic substances according to the direc
35、tive 80/778 EEC are found in the gaseousozone phase. Pesticides and polycyclic aromatic hydrocarbons are not by-products of the ozonemanufacturing processes.5 Test methods5.1 SamplingOzone generation is usually based on a continuous process gas flow mode positive pressure.Sampling of a volume is to
36、be controlled with a totalizing volumetric flow meter, the volumes beingexpressed at Normal Temperature and Pressure (NTP).In continuous monitoring methods the gas exit shall be open to ambient air or the gas pressureshall be controlled and the results corrected for effects of pressure.Sampling line
37、s shall be in stainless steel (see table A.1) or in polyfluorocarbone material resistantto ozone. The transfer of the gas from the sampling point to the analyzer shall be kept shorter than1 min.Expression of concentrations : concentration of ozone in a gas in g/m3(NTP), or kg/m3 (NTP),and for traces
38、 in cm3/m3(equivalent to ppm volume per volume (V/V) (1 g/m3(NTP) equals466,4 ppm (V/V) and 0,069 9 % (m/m) in oxygen or 0,077 3 % (m/m) in air).SANS 51278:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .Page 9EN 1278:1998NOTE : At conven
39、tional concentrations of about 20 g/m3 (NTP), the effect of difference ingas densities between ozone and oxygen-nitrogen is negligible. This is not the case whenhigher ozone concentrations are generated i.e. in oxygen.5.2 Analyses5.2.1 GeneralThe present method concerns the determination of ozone in
40、 air, oxygen or other process gases.The method is directly applicable for ozone concentrations in the range of 1 g/m3to 200 g/m3(NTP).5.2.2 PrincipleDirect iodometric titration.5.2.3 ReagentsAll reagents shall be of a recognized analytical grade and the water used shall conform to grade 2in accordan
41、ce with EN ISO 3696.5.2.3.1 Potassium iodide (KI) buffered solution.Potassium iodide (KI) solution at 20 g/l with sodium hydrogen phoshate (Na2HPO4.2 H2O)solution at 7,3 g/l and potassium dihydrogen phosphate (KH2PO4) solution at 3,5 g/l.5.2.3.2 Sodium thiosulfate : standard volumetric, solution c(N
42、a2S2O3) = 0,1 mol/l.5.2.3.3 Sulfuric acid, solution at 9 mol/l.5.2.3.4 Potassium iodate (KIO3) powdered.5.2.3.5 Potassium iodide (KI) crystalline5.2.3.6 Hydrochloric acid standard volumetric solution c(HCl) = 0,1 mol/l or sulfuric acidc(H2SO4) =0,05 mol/l.5.2.3.7 Zinc iodide (ZnI2)-starch indicator.
43、 Disperse 4 g starch into a small quantity of water. Addthe dispersion to a solution of 20 g zinc chloride (ZnCl2) in 100 ml water. The solution is boileduntil the volume has been reduced to 100 ml and finally diluted to 1 l while adding 2 g of ZnI2.SANS 51278:2008This s tandard may only be used and
44、 printed by approved subscription and freemailing clients of the SABS .Page 10EN 1278:19985.2.3.8 Standardization of sodium thiosulfate :5.2.3.8.1 Reactions5 KI + 5 H+5 HI + 5 K+KIO3+ H+HIO3+ K+HIO3+ 5 HI 3 I2+ 3 H2O3 I2+ 6 S2O32-6 I-+ 3 S4O62-5.2.3.8.2 DeterminationAdd 0,05 g of potassium iodate (5
45、.2.3.4), 0,5 g of potassium iodide (5.2.3.5) into 50 ml water anda further 50 ml water in a conical flask. After mixing, add 10 ml standard volumetric solution acid(5.2.3.6). Titrate the liberated iodine immediately with the sodium thiosulfate solution (5.2.3.2).5.2.3.8.3 CalculationThe concentratio
46、n, ct, expressed in moles per litre, of the sodium thiosulfate solution is given by :ccVVtat=where :cais the concentration ,in moles per litre, of the acid (5.2.3.6) ;V is the volume, in millilitres, of the acid (5.2.3.6) ;Vtis the volume, in millilitres, of the sodium thiosulfate solution used.5.2.
47、4 ApparatusOrdinary laboratory apparatus.5.2.5 Procedure5.2.5.1 Add the solution of potassium iodide (200 ml) to a standard gas washing vessel to give adepth of liquid of 10 cm to 15 cm. The use of fritted gas bubblers is not recommended.5.2.5.2 Connect a second identical flask in series as a guard
48、to check the ozone transfer andreaction.5.2.5.3 For ozone produced with air, bubble the process gas containing ozone at a flow rate ofabout 1 l/min until a total expected quantity of approximately 1 mmol ozone (0,048 g) has passed.SANS 51278:2008This s tandard may only be used and printed by approve
49、d subscription and freemailing clients of the SABS .Page 11EN 1278:1998For process gases containing higher ozone concentration (100 g/m3to 200 g/m3(NTP), set thegas flow at the level to pass about 1 mmol of ozone.5.2.5.4 Titrate the iodine formed in the flasks with the standard volumetric sodium thiosulfatesolution (5.2.3.2) immediately after acidification with not less than 5 ml of the acidifying solution(5.2.3.3). After titration to a pale yellow colour, add 0,5 ml of starch indicator (5.2.3.7) andcomplete the titration and record the result.5.2.
