BS EN ISO 9963-1-1996 Water quality - Determination of alkalinity - Determination of total and composite alkalinity《水质 强碱性的测定 第1部分 总强碱性和混合强碱性的测定》.pdf

1、BRITISH STANDARD BS EN ISO 9963-1:1996 BS 6068-2.51: 1996 Water quality Determination of alkalinity Part 1: Determination of total and composite alkalinity The European Standard EN ISO 9963-1:1995 has the status of a British Standard ICS 13.060.40BSEN ISO 9963-1:1996 This British Standard, having be

2、en prepared under the directionof the Health and Environment Sector Board, was published under the authority ofthe Standards Board and comesinto effect on 15May1996 BSI 07-1999 The following BSI references relate to the work on this standard: Committee reference EH/3/2 Draft for comment 92/50314 DC

3、ISBN 0 580 25293 0 Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical CommitteeEH/3,Water quality, to SubcommitteeEH/3/2,Physical, chemical and biochemical methods, upon which the following bodies were represented: The Association of

4、the Laboratory Supply Industry British Agrochemicals Association Ltd. British Ceramic Research British Gas plc British Soft Drinks Association Ltd. Chemical Industries Association Convention of Scottish Local Authorities Department of the Environment (Water Directorate) Department of Trade and Indus

5、try (Laboratory of the Government Chemist) GAMBICA (BEAMA) Ltd. Industrial Water Society Insitution of Water and Environmental Management National Rivers Authority Royal Society of Chemistry Soap and Detergent Industry Association Society of Chemical Industry Swimming Pool and Allied Trades Associat

6、ion Ltd. Water Companies Association Water Research Centre Water Services Association of England and Wales Amendments issued since publication Amd. No. Date CommentsBSEN ISO 9963-1:1996 BSI 07-1999 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 1 Scope 3 2

7、Normative references 3 3 Definitions 3 4 Principle 3 5 Reagents 4 6 Apparatus 5 7 Sampling and sample treatment 5 8 Procedure 5 9 Expression of results 6 10 Test report 6 Annex A (informative) Information on factors for the conversion of alkalinity values to alternative units 7 Annex ZA (normative)

8、Normative references to international publications with their relevant European publications 8 List of references Inside back coverBSEN ISO 9963-1:1996 ii BSI 07-1999 National foreword This British Standard has been prepared by SubcommitteeEH/3/2and is the English language version ofENISO9963-1:1995

9、 Water quality Determination of alkalinity Part1: Determination of total and composite alkalinity published by the European Committe for Standardization (CEN). It is identical withISO9963-1:1994, published by the International Organization for Standardization (ISO). A British Standard does not purpo

10、rt to include all the necessary provisions of 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. Cross-references Publication referred to Corresponding British Standard IS

11、O 3696:1987 BS 3978:1987 Specification for water for laboratory use BS EN 25667:1993 Water quality. Sampling EN 25667-1:1993 (ISO 5667-1:1980) BS EN 25667-1:1994 Guidance on the design of sampling programmes EN 25667-2:1993 (ISO 5667-2:1991) BS EN 25667-2:1993 Guidance on sampling techniques BS 6068

12、 Water quality Part 1 Glossary ISO 6107-2:1989 Section 1.2:1990 Additional terms relating to types of water, and treatment and storage of water and waste water, and terms used in sampling and analysis of water IEC 746-2:1982 BS 6438 Electrochemical analyzers Part 2:1984 Method for specifying perform

13、ance of pH value analyzers Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN title page, pages 2 to 8, 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

14、indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 9963-1 December 1995 ICS 13.060.40 Descriptors: Water, quality, water tests, chemical analysis, determination, alkalinity, volumetric analysis English version Water quality Determinati

15、on of alkalinity Part 1: Determination of total and composite alkalinity (ISO 9963-1:1994) Qualit de leau Dtermination de lalcalinit Partie 1: Dtermination de lalcalinit totaleet composite (ISO 9963-1:1994) Wasserbeschaffenheit Bestimmung der Alkalinitt Teil 1: Bestimmung de gesamten und der zusamme

16、ngesetzten Alkalinitt (ISO 9963-1:1994) This European Standard was approved by CEN on1995-10-11. 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-

17、date lists and bibliographical 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 t

18、he responsibility 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

19、, Norway, Portugal, 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 All rights of reproduction and communication in any form and by an

20、y means reserved in all countries to CEN and its members Ref. No. EN ISO 9963-1:1995 EEN ISO 9963-1:1995 BSI 07-1999 2 Foreword The text of the International Standard from ISO/TC147, Water quality, of the International Organization for Standardization (ISO) has been taken over as a European Standard

21、 by the Technical Committee CEN/TC230, Water analysis. This European Standard consists of the following parts: EN ISO 9963-1, Water quality Determination of alkalinity Part 1: Determination of total and composite alkalinity. EN ISO 9963-2, Water quality Determination of alkalinity Part 2: Determinat

22、ion of carbonate alkalinity. 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 byJune1996, and conflicting national standards shall be withdrawn at the latest byJune1996. According to the CEN/CENELEC I

23、nternal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom. NOTENormative references to Interna

24、tional Standard are listed inAnnex ZA (normative).EN ISO 9963-1:1995 BSI 07-1999 3 1 Scope This part of ISO9963specifies a method for the titrimetric determination of alkalinity. It is intended for the analysis of natural and treated water, and waste water, and can be used directly for waters having

25、 an alkalinity concentration of up to20mmol/l. For samples containing higher concentrations of alkalinity, a smaller test portion can be used for analysis. The recommended lower limit is0,4mmol/l. Suspended matter in the form of carbonate may interfere with the analysis. This interference can be red

26、uced by filtration prior to the titration. The endpoint detection, using a pH-meter, is less prone to interferences than the use of the indicator. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part ofISO9963. At

27、 the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part ofISO9963 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maint

28、ain registers of currently valid International Standards. ISO 385-1:1984, Laboratory glassware Burettes Part 1: General requirements. ISO 3696:1987, Water for analytical laboratory use Specification and test methods. ISO 5667-1:1980, Water quality Sampling Part1: Guidance on the design of sampling p

29、rogrammes. ISO 5667-2:1991, Water quality Sampling Part2: Guidance on sampling techniques. ISO 6107-2:1989, Water quality Vocabulary Part2. IEC 746-2:1982, Expression of performance of electrochemical analyzers Part 2: pH Value. 3 Definitions For the purposes of this part ofISO9963, the following de

30、finitions apply. 3.1 alkalinity (A) the quantitative capacity of aqueous media to react with hydrogen ions ISO6107-2 3.2 methyl red (methyl orange) endpoint alkalinity an arbitrary measurement of the total alkalinity (A T ) of water obtained by titration to the methyl red (methyl orange) indicator e

31、ndpoint (pH4,5); to assess the equivalent hydrogen carbonate, carbonate and hydroxide concentration of water 3.3 phenolphthalein endpoint alkalinity; composite alkalinity (A p ) the measurement by titration to the phenolphthalein endpoint (pH8,3) of that portion of alkalinity arbitrarily attributed

32、to all the hydroxyl and half the carbonate content of a water ISO6107-2 NOTE 1The alkalinity of water is primarily a function of the hydrogen carbonate, carbonate and hydroxide concentrations. Other buffering substances (X) such as ammonia, borate, phosphate, silicate and organic anions may be inclu

33、ded in the determination. by definition, composite alkalinity is zero for waters which have a pH value of8,3or less 4 Principle The sample is titrated with standard acid solution to fixed pH endpoint values of8,3and4,5. These endpoints, which are determined visually or potentiometrically, are the se

34、lected equivalence points for the determinations of the three principal components: hydrogen carbonate, carbonate and hydroxide. The pH8,3endpoint approximates to the equivalent concentrations of carbonate and carbon dioxide and represents the titration of approximately all the hydroxide and half of

35、 the carbonate present. The pH4,5endpoint approximates the equivalence point for hydrogen ion and hydrogen carbonate and allows for the determination of the total alkalinity of the sample. NOTE 2The equivalent point values depend on the ionic strength as well as the concentration of total inorganic

36、carbon and may not always be optimum at the chosen endpoints. Whilst methyl orange and methyl red have been commonly used in the past as indicators for the determination of total alkalinity, in practice the use of different indicator systems produce slightly different results in alkalinity titration

37、s. For alkalinity determinations in accordance with this part ofISO9963, the correct bromocresol green-methyl red indicator solution as defined in5.6 should be used.EN ISO 9963-1:1995 4 BSI 07-1999 5 Reagents Use only reagents of recognized analytical grade. Commercially available, ready-made soluti

38、ons may be used. 5.1 Water, grade2in accordance withISO3696, free of interfering concentrations of acid or alkali and with a conductivity of less than0,1mS/m. 5.2 Sodium carbonate, standard solution, c(Na 2 CO 3 ) . 0,025 mol/l. Dry3g to5g of sodium carbonate (Na 2 CO 3 ) at250 C 10Cfor4h. Allow to

39、cool in a desiccator. Dissolve2,65g 0,20g(m, weighed to the nearest0,001g) in water and dilute in a volumetric flask to1000ml. This solution is stable for at least one month if stored in a refrigerator at4 C and8 C. 5.3 Hydrochloric acid, c(HCl) . 0,10mol/l. Dilute8,6ml 0,1ml of hydrochloric acid (1

40、,16g/ml)to1000ml with water. Standardize this solution as follows, using either potentiometric(5.3.1) or visual endpoint detection(5.3.2). 5.3.1 Potentiometric detection Pipette25,0ml 01ml (V 1 ) of the sodium carbonate solution (5.2) into a titration vessel and add75ml5ml of water (5.1). Place the

41、vessel on a magnetic stirrer and dip into the solution a plastics-coated magnetic stirrer bar and electrodes previously connected to a calibrated pH-meter. Start the stirrer and stir at a rate at which a vortex is just not perceptible. Titrate with0,10mol/l hydrochloric acid solution (5.3) until the

42、 meter readspH4,5 0,05. Note the volume V 2 , in millilitres, of acid consumed. 5.3.2 Visual endpoint detection Pipette25,0ml 0,1ml(V 1 ) of approximately0,025mol/l sodium carbonate solution (5.2) into a250ml Erlenmeyer flask, and add75ml5ml of water and0,1ml 0,02ml of bromocresol green-methyl red i

43、ndicator solution(5.6). Titrate with0,10mol/l hydrochloric acid solution (5.3) until the greenish-blue colour disappears. Note the volume V 2 , in millilitres, of acid consumed. 5.3.3 Blank determination Using100ml5ml of water, carry out a blank determination according to the appropriate procedure (

44、5.3.1 or 5.3.2) and note the volume V 3 , in millilitres, of acid consumed. 5.3.4 Calculation of the amount-of-substance concentration of the hydrochloric acid where Standardize this solution at least weekly. 5.4 Hydrochloric acid, c(HCl) . 0,02 mol/l. Pipette100ml1ml of hydrochloric acid solution(5

45、.3) into a500ml volumetric flask. Dilute to volume with water and mix well. Prepare freshly before use. Calculate the amount-of-substance concentration as follows: c(HCl,2) = 0,2 c(HCl,1) where 5.5 Phenolphthalein indicator solution Dissolve1,0g 0,1g of phenolphthalein in100ml 2ml of ethanol 90% (V/

46、V) ethanol and dilute with water to200ml 4ml. Mix well. 5.6 Bromocresol green-methyl red indicator solution Dissolve0,200g 0,005g of bromocresol green and0,015g 0,002g of methyl red in100ml 4ml of ethanol 90%(V/V) ethanol. Store in an amber glass bottle. c(HCl,1) is the actual concentration, express

47、ed in moles per litre, of the nominally0,10mol/l hydrochloric acid solution (5.3); m is the mass, in grams, of sodium carbonate taken for the preparation of standard solution (5.2); V 1 is the volume, in millilitres, of sodium carbonate standard solution (5.2) taken for titration (normally25ml); V 2

48、 is the volume, in millilitres, of hydrochloric acid solution (5.3) consumed in the titration of the sodium carbonate standard solution(5.2); V 3 is the volume, in millilitres, of hydrochloric acid solution (5.3) consumed in the blank titration. c(HCl,1) is the actual concentration, expressed in mol

49、es per litre, of the nominally0,10mol/l hydrochloric acid solution (5.3); c(HCl,2) is the actual concentration, expressed in moles per litre, of the nominally0,02mol/l hydrochloric acid solution (5.4).EN ISO 9963-1:1995 BSI 07-1999 5 5.7 Sodium thiosulfate solution, c(Na 2 S 2 O 3 .5H 2 O) . 0,1mol/l. Dissolve2,5g 0,2g of sodium thiosulfate pentahydrate (Na 2 S 2 O 3 .5H 2 O) in100ml 5ml of water. Store in an amber glass bottle in the refrigerator for a maximum of six months. 6 Apparat