1、BS EN 12671:2009ICS 13.060.20; 71.100.80NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDChemicals used fortreatment of waterintended for humanconsumption Chlorine dioxidegenerated in situThis British Standardwas published under theauthority of the StandardsPolic
2、y and StrategyCommittee on 30 June2009. BSI 2009ISBN 978 0 580 58195 3Amendments/corrigenda issued since publicationDate CommentsBS EN 12671:2009National forewordThis British Standard is the UK implementation of EN 12671:2009. Itsupersedes BS EN 12671:2000 which is withdrawn.The UK participation in
3、its preparation was entrusted to TechnicalCommittee CII/59, Chemicals for drinking water treatment.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are respon
4、sible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.BS EN 12671:2009EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 12671January 2009ICS 71.100.80 Supersedes EN 12671:2000 English VersionChemicals used for treatment of water intended fo
5、r humanconsumption - Chlorine dioxide generated in situProduits chimiques utiliss pour le traitement de leaudestine la consommation humaine - Dioxyde de chloreproduit sur siteProdukte zur Aufbereitung von Wasser fr denmenschlichen Gebrauch - Vor Ort erzeugtes ChlordioxidThis European Standard was ap
6、proved by CEN on 29 November 2008.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-to-date lists and bibliographical references concerning such nation
7、alstandards may be obtained on application to the CEN Management Centre 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 the responsibility of a CEN member into its own language and notif
8、ied to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
9、 Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation
10、 in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12671:2009: EBS EN 12671:2009EN 12671:2009 (E) 2 Contents Page Foreword 3Introduction . 41 Scope 52 Normative references 53 Description . 53.1 Identification . 53.2 Presentation form 63.3 Physical properties 63.4 Ch
11、emical properties 74 Purity criteria 84.1 General 84.2 Composition of in-situ generated product 84.3 Impurities and main by-products . 84.4 Chemical parameters 85 Test methods 95.1 Sampling . 95.2 Determination of chlorine dioxide and chlorite concentrations . 96 Labelling - Storage - Distribution s
12、ystem . 126.1 Risk and safety labelling according to the EU Directives 126.2 Means of distribution 136.3 Storage, stability 14Annex A (informative) General information on chlorine dioxide 15A.1 Origin 15A.2 Use 16A.3 Spectrometric method for specific determination of CIO216A.4 Determination of chlor
13、ite and chlorate ions contents in aqueous chlorine dioxide as produced by the reactors . 19Annex B (normative) General rules relating to safety. . 21B.1 Rules for safe handling and use 21B.2 Emergency procedures . 21Bibliography 22BS EN 12671:2009EN 12671:2009 (E) 3 Foreword This document (EN 12671:
14、2009) 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 of an identical text or by endorsement, at the latest by July 2009, and conflicting nati
15、onal standards shall be withdrawn at the latest by July 2009. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. Significant technical di
16、fferences between this edition and EN 12671:2000 are as follows: a) deletion of the reference to EU Directive 80/778/EEC of July 15,1980 in order to take into account the latest Directive in force (see 1); This document supersedes EN 12671:2000. According to the CEN/CENELEC Internal Regulations, the
17、 national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Nor
18、way, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 12671:2009EN 12671:2009 (E) 4 Introduction In respect of potential adverse effects on the quality of water intended for human consumption, caused by the product covered by this document: 1) t
19、his document provides no information as to whether the product may be used without restriction in any of the Member States of the EU or EFTA; 2) it should be noted that, while awaiting the adoption of verifiable European criteria, existing national regulations concerning the use and/or the character
20、istics of this product remain in force. NOTE Conformity with this standard does not confer or imply acceptance or approval of the product in any of the Member States of the EU or EFTA. The use of the product covered by this document is subject to regulation or control by National Authorities. BS EN
21、12671:2009EN 12671:2009 (E) 5 1 Scope This document is applicable to chlorine dioxide generated on site for treatment of water intended for human consumption. It describes the characteristics for chlorine dioxide and specifies the composition and the corresponding test methods for chlorine dioxide.
22、It gives information on its use in water treatment. It also determines the rules relating to safe handling and use of chlorine dioxide generated on site (see Annex B). 2 Normative references The following referenced documents are indispensable for the application of this document. For dated referenc
23、es, only the edition cited applies. For undated references the latest edition of the referenced document (including any amendments) applies. EN ISO 3696:1995, Water for analytical laboratory use Specification and test methods (ISO 3696:1987) ISO 3165, Sampling of chemical products for industrial use
24、 Safety in sampling ISO 6206, Chemical products for industrial use Sampling Vocabulary 3 Description 3.1 Identification 3.1.1 Chemical name Chlorine dioxide. 3.1.2 Synonym or common name None. 3.1.3 Relative molecular mass 67,46 3.1.4 Empirical formula ClO23.1.5 Chemical formula OClO_KK(resonance st
25、ructure) 3.1.6 CAS Registry Number 1)10 049 - 04-4 1) Chemical Abstracts Service Registry Number. BS EN 12671:2009EN 12671:2009 (E) 6 3.1.7 EINECS reference 2)233 162 - 8 3.2 Presentation form For water treatment, chlorine dioxide is generated in situ as an aqueous solution on or near the site of us
26、e and transferred to the site of use. 3.3 Physical properties 3.3.1 Appearance The pure product is an orange gas or liquid, which forms a yellow solution in water. NOTE If the solution becomes red-brown, it is sign of decomposition. 3.3.2 Density Gas: 3,09 g/l, (2,4 g/l relative, air = 1) at 273 K a
27、nd 101,3 kPa 3). Liquid: 1,64 g/ml at 20 C. 3.3.3 Solubility in water In Table 1 the solubility values (S) for chlorine dioxide are given in grams per m water at a pressure of 101,3 kPa for different temperatures 1: Table 1 Solubility values Temperature of water C S value : gasg/mOHg/m3230 70 0,7 5
28、(60,3)10 (53,7)15 4520 (42,7)25 (33) 30 (30,1)35 26,5 0,8 NOTE 1 S is a ratio, not an absolute value of concentration. NOTE 2 The S values are directly measured values except those in brackets which are extrapolated data. 3.3.4 Vapour pressure The vapour pressure of pure chlorine dioxide as a functi
29、on of temperature is given in Table 2. 2) European Inventory of Existing Commercial Chemical Substances. 3 ) 100 kPa = 1 bar BS EN 12671:2009EN 12671:2009 (E) 7 Table 2 Vapour pressure of pure chlorine dioxideTemperature C Vapour pressure kPa 0 82,35 90,4 10 98,811 100,5 20 116,5 (extrapolated) 25 1
30、25,8 (extrapolated)30 135,3 (extrapolated) 35 145,1 (extrapolated)40 155,0 (extrapolated) 3.3.5 Boiling point at 101,3 kPa 4)11 C (for pure chlorine dioxide). 3.3.6 Crystallisation point - 59 C (for pure chlorine dioxide). 3.3.7 Specific heat The specific heat of solutions of chlorine dioxide is ver
31、y similar to that of pure water. 3.3.8 Viscosity (dynamic) The dynamic viscosity of solutions of chlorine dioxide is very similar to that of pure water. 3.3.9 Critical temperature 153 C (for pure chlorine dioxide). 3.3.10 Critical pressure Not applicable. 3.3.11 Physical hardness Not applicable. 3.3
32、.12 Dissolution heat The heat of the dissolution in water is 26,8 kJ/mol (exothermic). 3.4 Chemical properties Chlorine dioxide is a molecule containing an unpaired electron and has the characteristics of a “molecule-free-radical“. Relevant Redox potentials of chlorine dioxide and related molecules
33、are (Eo values at 25 C in volts): 4) 100 kPa = 1 bar BS EN 12671:2009EN 12671:2009 (E) 8 HCIO2+ 3H+ 4e- CI-+ 2H2O 1,57 CIO2(dissolved gas) + 1e- CIO2-1,15 CIO3-+ 1e-+ 2H+ ClO2+ H2O 1,15 ClO2(dissolved liquid) + 1e- CIO2-0,95 CIO2-+ 4e-+ 4 H+ CI-+ 2H2O 0,78 4 Purity criteria 4.1 General This European
34、 Standard specifies the minimum purity requirements for chlorine dioxide generated in situ used for the treatment of water intended for human consumption. Limits are given for impurities commonly present in the product. Depending on the raw material and the manufacturing process, other impurities ma
35、y be present and, if so, this shall be notified to the user and when necessary to relevant authorities. NOTE Users of this product should check the national regulations in order to clarify whether it is of appropriate purity for treatment of water intended for human consumption, taking into account
36、raw water quality, required dosage, contents of other impurities and additives used in the product not stated in this product standard. Limits have been given for impurities and chemical parameters where these are likely to be present in significant quantities from the current production process and
37、 raw materials. If the production process or raw materials lead to significant quantities of impurities, by-products or additives being present, this shall be notified to the user. 4.2 Composition of in-situ generated product Chlorine dioxide (ClO2) is produced as aqueous solution on or near the sit
38、e of use. For safety reasons the aqueous ClO2-solution without intermediate storage in a storage tank (i.e. without headspace) may not exceed a concentration of 20 g/l. The concentration of the aqueous ClO2solution with intermediate storage in a storage tank (i.e. with headspace) should not exceed a
39、 concentration of 3 g/l, to ensure an adequate distance to the explosion limit (see B.1). 4.3 Impurities and main by-products Impurities and main by-products of the starting products used for the generation (indicated in A.1.1) can be found in the in situ generated product in respective proportional
40、 concentrations. Inadequate design, operation and maintenance of reactors can give rise to the formation of chlorine and traces of chlorate ion and, eventually, the presence of unreacted chlorite, chlorate and/or chlorine (see 5); for analysis see 5.2 and A.4. 4.4 Chemical parameters Limits of chemi
41、cal parameters being potentially present in chlorine dioxide solution have been specified in the corresponding EN standards of the starting products (indicated in A.1.1). BS EN 12671:2009EN 12671:2009 (E) 9 5 Test methods 5.1 Sampling Sampling of chlorine dioxide solutions shall avoid photochemical
42、decompositions, losses by evaporation of the product and consumption by the glassware and dilution water. Samples shall be taken at the exit of the reactor or from the storage tank with a sampling tube and the analytical procedures started as fast as possible. In order to achieve these objectives th
43、e following step by step procedure shall be adopted: sampling shall be made in accordance with the general requirements given in ISO 3165 and take into account ISO 6206; all glassware is to be conditioned immediately before sampling, with the solution under investigation and this preliminary rinsing
44、 sample is to be discarded; liquid samples for analytical control shall be introduced directly into the analytical reagent solutions; the sampling device and procedure shall take care that the sample is directly contacted with the analytical reagent without running along the walls of the analytical
45、glassware; the sample vessels shall be stoppered leaving no -or only a little- a head-space, to store the sample with reagent mixture; at high concentration of chlorine dioxide (10 g/l) the samples shall be collected in a vessel, containing water; the analytical result shall be corrected accordingly
46、 for the dilution factor; titration analysis shall best be carried out immediately after sampling plus reaction; if immediate titration or measurement is not possible, prior to the analytical measurements the sample plus reagent shall be stored in the dark at low temperature about 5 C and contact wi
47、th ambient air shall be avoided; if immediate collection and analysis are not possible, sample the reactor effluent in a 250 ml conical flask stored on crushed ice and, by introducing the liquid at the bottom of the flask and fill the flask completely allowing overflow of chlorine dioxide solution.
48、The volume of the samples shall be adjusted in accordance with the analytical procedure described hereafter. 5.2 Determination of chlorine dioxide and chlorite concentrations 5.2.1 General This standard method concerns the determination of chlorine dioxide and chlorite concentrations in stored solut
49、ion. NOTE Other oxidizing agents could interfere with the determination. 5.2.2 Principle 5.2.2.1 General Phosphate-buffered iodide is first reacted with the chlorine dioxide sample and titrated at pH 7,2 and subsequently acidified to pH 2 and titration is continued. 5.2.2.2 With iodometry at pH 7,2 ClO2+ l- ClO2-+1/2 l2(1) BS EN 12671:2009EN 12671:2009 (E) 10 and Cl2+ 2 l- l2+ 2Cl- (2)5.2.2.3 Subsequent iod
