BS EN ISO 8467-1995 Water quality - Determination of permanganate index《水质 高锰酸盐指数测定》.pdf

1、BRITISH STANDARD BS EN ISO 8467:1995 BS 6068-2.32: 1995 Water quality Determination of permanganate index The European Standard EN ISO 8467:1995 has the status of a British StandardBSENISO8467:1995 This British Standard, having been prepared under the directionof the Environment andPollution Standar

2、ds Policy Committee, was published underthe authority of the Standards Board and comes intoeffect on 15 May 1995 BSI 10-1999 First published as BS 6068-2.32 July 1987 Second edition as BSENISO8467May 1995 The following BSI references relate to the work on this standard: Committee reference EPC/44 Sp

3、ecial announcement in BSINews, May 1994 ISBN 0 580 23435 5 Cooperating organizations The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries: Austria Oesterreichisches Nor

4、mungsinstitut Belgium Institut belge de normalisation Denmark Dansk Standard Finland Suomen Standardisoimisliito, r.y. France Association franaise de normalisation Germany Deutsches Institut fr Normung e.V. Greece Hellenic Organization for Standardization Iceland Technological Institute of Iceland I

5、reland National Standards Authority of Ireland Italy Ente Nazionale Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portugus da Qualidade Spain Asociacin Espaola de Normaliza

6、cin y Certificacin Sweden Standardiseringskommissionen i Sverige Switzerland Association suisse de normalisation United Kingdom British Standards Institution Amendments issued since publication Amd. No. Date CommentsBSENISO8467:1995 BSI 10-1999 i Contents Page Cooperating organizations Inside front

7、cover National foreword ii Foreword 2 Introduction 3 1 Scope 3 2 Normative reference 3 3 Definition 3 4 Principle 3 5 Reagents 3 6 Apparatus 4 7 Sampling and samples 4 8 Procedure 4 9 Expression of results 5 10 Test report 6 National annex NA (informative) Committees responsible Inside back cover Ta

8、ble 1 5 Table 2 5BSENISO8467:1995 ii BSI 10-1999 National foreword This British Standard has been prepared under the direction of the Environment and Pollution Standards Policy Committee and is the English language version ofENISO 8467:1995 Water quality Determination of permanganate index published

9、 by the European Committee for Standardization (CEN). It is identical withISO8467:1993, published by the International Organization for Standardization (ISO). This standard supersedesBS6068-2.32:1987, which is withdrawn. A British Standard does not purport to include all the necessary provisions of

10、a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN ISOtitle page, page

11、s 2 to 6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 8467 March 1995 ICS 13.060.4

12、0 Descriptors: Water, quality, water tests, chemical analysis, determination, permanganate number English version Water quality Determination of permanganate index (ISO 8467:1993) Qualit de leau Dtermination de lindice de permanganate (ISO 8467:1993) Wasserbeschaffenheit Bestimmung des Permanganat-I

13、ndex (ISO 8467:1993) This European Standard was approved by CEN on 1994-11-03. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bib

14、liographical references concerning such national standards 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 translation under the responsibility

15、of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal

16、, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1995 Copyright reserved to CEN members Ref. No. EN ISO 8467:1995 EENISO8467:1995 BSI 10-1

17、999 2 Foreword This European Standard has been taken over by the Technical Committee CEN/TC 230, Water analysis, from the work of ISO/TC 147, Water quality, of the International Organization for Standardization (ISO). This European Standard shall be given the status of a National Standard, either by

18、 publication of an identical text or by endorsement, at the latest by September 1995 and conflicting national standards shall be withdrawn at the latest by September 1995. According to the CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austri

19、a, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.ENISO8467:1995 BSI 10-1999 3 Introduction The permanganate index is a conventional measure of the contamination by organic and oxid

20、izable inorganic matter in a water sample. It is primarily intended for judging the quality of potable water and raw waters, such as well and surface waters. More heavily contaminated waters may be analysed, provided an appropriate pre-dilution step is adopted. The permanganate index can be determin

21、ed for waters containing less than 500 mg/l of chloride ion. Reducing compounds such as iron(II) salts, nitrites or hydrogen sulfide may contribute to the permanganate index but are not classified as impurities. The permanganate index cannot be considered as a measure of the the oretical oxygen dema

22、nd or the total content of organic matter. Many organic compounds are only partially oxidized in this test, as oxidation is generally incomplete. Volatile matter that evaporates before the addition of permanganate is not included. The method is not recommended for determining organic load in waste w

23、aters; for this purpose the chemical oxygen demand should be determined as described inISO6060:1989, Water quality Determination of the chemical oxygen demand. The method is simple and convenient for surveying the quality of a large number of water samples. 1 Scope This International Standard specif

24、ies a method for the determination of the permanganate index of water. It is primarily intended for water for human consumption and domestic use, drinking water, natural mineral water, well and table water, as well as water from swimming pools. It is used for the determination of the parameter “oxid

25、izability”. It is applicable to waters having a chloride ion concentration of less than300mg/l. Samples having a permanganate index over10mg/l should be diluted before analysis. The lower limit of the optimum range of the test is0,5mg/l. 2 Normative reference The following standard contains provisio

26、ns which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibi

27、lity of applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 385-1:1984, Laboratory glassware Burettes Part 1: General requirements. 3 Definition 3.1 permanganate index (of water) the mass concentr

28、ation of oxygen equivalent to the amount of permanganate ion consumed when a water sample is treated with that oxidant under defined conditions 4 Principle Heating of a sample in a boiling water-bath with a known amount of potassium permanganate and sulfuric acid for a fixed period of time (10 min).

29、 Reduction of part of the permanganate by oxidizable material in the sample and determination of the consumed permanganate by addition of an excess of oxalate solution, followed by titration with permanganate. NOTE 1The suggested maximum permanganate index of10mg/l is equivalent to a consumption of

30、approximately60% of the added permanganate by the non-diluted sample. 5 Reagents During the analysis, use only reagents of recognized analytical grade and only distilled water, water from a reverse osmosis or water of equivalent purity. Do not use deionized water from an organic ion exchanger. NOTE

31、2Non-reducing water can be prepared as follows. Add10ml of sulfuric acid (5.3) and a small excess of the potassium permanganate stock solution (5.6) to1litre of distilled water. Distil in an all-glass apparatus and discard the first100ml of distillate. Store in a glass bottle with a glass stopper. T

32、he volume of the consumed potassium permanganate standard solution V 0(see8.4) shall not exceed0,1ml, otherwise the procedure shall be repeated or a water of lower organic content shall be used. 5.1 Sulfuric acid, (H 2 SO 4 ) =1,84g/ml,18mol/l. 5.2 Sulfuric acid, c(H 2 SO 4 ) =7,5mol/l. Add slowly,

33、while stirring continuously,420ml of sulfuric acid (5.1) to500ml of water. Allow to cool and dilute to1litre. 5.3 Sulfuric acid, c(H 2 SO 4 ) =2mol/l. Add slowly, while stirring continuously,110ml of sulfuric acid (5.1) to about500ml of water. Slowly add potassium permanganate solution (5.7) until a

34、 faint pink colour persists. Allow to cool, dilute with water to1litre and mix.ENISO8467:1995 4 BSI 10-1999 5.4 Sodium oxalate, stock solution, c(Na 2 C 2 O 4 )=0,05mol/l. Dry sodium oxalate at120 C for2h. Dissolve6,700g of the dried solid in water in a1000ml one-mark volumetric flask. Make up to th

35、e mark with water and mix. This solution is stable for6months if stored in a dark place. 5.5 Sodium oxalate, standard volumetric solution, c(Na 2 C 2 O 4 ) =5mmol/l. Pipette100ml 0,25ml of the sodium oxalate stock solution (5.4) into a1000ml one-mark volumetric flask, make up to the mark with water

36、and mix. This standard volumetric solution is stable for2weeks. NOTE 3Commercially available ready-made solutions may be used. 5.6 Potassium permanganate, stock solution, c(KMnO 4 ) . 20mmol/l. Dissolve about3,2g of potassium permanganate in water and make up to 1000ml. Heat the solution to90 C to95

37、 C for2h, cool and store for not less than2days. Decant the clear solution and store in a dark bottle. 5.7 Potassium permanganate, volumetric solution, c(KMnO 4 ) . 2mmol/l. Pipette100ml of the potassium permanganate stock solution (5.6) into a1000ml, one-mark volumetric flask. Make up to the mark w

38、ith water and mix. This volumetric solution is relatively stable for several months if it is stored in the dark. The procedure described in8.5 automatically allows for its exact concentration to be included in the calculation in9.1. 6 Apparatus Usual laboratory apparatus, and the following should be

39、 used 6.1 Water-bath, with a rack for test tubes, of sufficient capacity and power to ensure that the solutions in all the test tubes quickly reach and are maintained at a temperature between96 C and98 C, during both the initial heating and the reaction stages. 6.2 Test tubes, of length150mm to200mm

40、, diameter25mm to35mm and wall thickness0,5mm to1mm. Keep the test tubes exclusively for the determination of the permanganate index. Clean all new test tubes by heating with acidified permanganate solution. This shall be checked by performing blank determinations until the values are adequately low

41、 and constant. A blank value V 0shall typically not exceed0,1ml. 6.3 Burette, of capacity10ml, preferably of the piston type, graduated in divisions of0,02ml, and conforming to the requirements ofISO385-1. 6.4 Measuring flasks, of capacity100ml and1000ml. 6.5 Volumetric pipettes, of capacity5ml,10ml

42、,25ml,50ml, and100ml. 7 Sampling and samples Immediately after receiving the sample in the laboratory, add5ml of sulfuric acid (5.2) per litre of sample, if this was not done during sampling in the field, regardless of whether the sample is to be stored before analysis. Analyse the samples as soon a

43、s possible and not later than2days after sampling. Keep them in the dark at0 C to5 C if the storage time exceeds6h. Shake the storage bottles and make sure that their contents are well homogenized when withdrawing a test portion for analysis. 8 Procedure 8.1 Check that all flasks and test tubes (6.2

44、) used during the procedure are perfectly clean (see6.2). 8.2 Dilute samples having a high permanganate index, so that the results for the diluted samples fall within the range0,5mg/l to10mg/l. 8.3 Pipette25,0ml 0,25ml of the test sample (or the diluted test sample) into a test tube. Add5ml 0,5ml of

45、 sulfuric acid (5.3) and mix by swirling gently. Place the test tube in the boiling water-bath (6.1) for10min 2min. Add5ml 0,05ml of potassium permanganate volumetric solution (5.7) and commence timing. After10min 15s, add5ml 0,05ml of the sodium oxalate standard volumetric solution (5.5) and wait u

46、ntil the solution is colourless. Titrate, whilst hot, with potassium permanganate volumetric solution (5.7) to a faint pink colour which persists for about30s. Note the volume V 1of permanganate solution consumed. 8.4 Carry out a blank test in parallel with the determination, using the same procedur

47、e, but replacing the test portion with25ml of water. Note the volume V 0of permanganate solution consumed. Retain the titrated solution for standardization of the potassium permanganate volumetric solution(5.7), as described in8.5.ENISO8467:1995 BSI 10-1999 5 8.5 To the titrated solution retained fr

48、om the blank test (8.4), add 5,00ml 0,05ml of the sodium oxalate standard volumetric solution (5.5). Reheat the solution, if necessary, to about80 C and titratewith potassium permanganate volumetric solution (5.7) until the appearance of a pink colour which persists for about30s. Note the volume V 2

49、of permanganate solution consumed. NOTE 4It is good practice to leave the titrated solutions in the test tubes until they are required for the next determination of permanganate index. 9 Expression of results 9.1 Calculation Calculate the permanganate index, I Mn , expressed in milligrams of oxygen per litre, using the expression where where 9.2 Precision 9.2.1 Within-laboratory standard deviation Table 1 9.2.2 Total standard deviation Table 2 . . . (1) V 0 is the volume, in millilitres, of permanganate solution consumed