EN ISO 9963-1:1995

Water quality - Determination of alkalinity - Part 1: Determination of total and composite alkalinity (ISO 9963-1:1994)

Specifies a method for the titrimetric determination of alkalinity. Intended for the analysis of natural and treated water, and waste water, and can be used directly for waters having an alkalinity concentration of up to 20 mmol/l. For samples containing higher concentrations of alkalinity, a smaller test portion can be used for analysis. The recommended lower limit is 0,4 mmol/l.

Wasserbeschaffenheit - Bestimmung der Alkalinität - Teil 1: Bestimmung der gesamten und der zusammengesetzten Alkalinität (ISO 9963-1:1994)

Dieser Teil von ISO 9963 legt ein Verfahren zur titrimetrischen Bestimmung der Alkalinität fest. Es dient zur Analyse von natürlichem und behandeltem Wasser und Abwasser und kann direkt für Wasser mit einer Alkalinitätskonzentration von bis zu 20 mmol/l eingesetzt werden. Bei Proben mit höherer Alkalinitätskonzentration kann ein kleineres Aliquot zur Analyse verwendet werden. Die empfohlene Nachweisgrenze ist 0,4 mmol/l. Suspendierte Stoffe in Form von Carbonaten können die Analyse stören.

Qualité de l'eau - Détermination de l'alcalinité - Partie 1: Détermination de l'alcalinité totale et composite (ISO 9963-1:1994)

La présente partie de l'ISO 9963 prescrit une méthode pour la détermination titrimétrique de l'alcalinité. Elle est destinée à l'analyse de l'eau naturelle et traitée, de l'eau résiduaire et peut être directement utilisée pour les eaux ayant une concentration d'alcalinité jusqu'à 20 mmol/l. Pour les échantillons contenant des concentrations supérieures d'alcalinité, il convient de prendre une portion d'essai plus faible pour l'analyse. La limite inférieure est de 0,4 mmol/l. Les matières en suspension sous forme de carbonate peuvent interférer avec l'analyse. Cette interférence peut être réduite par filtration avant le titrage. La détection du point de virage à l'aide d'un pH-mètre est moins sujette aux interférences que l'usage d'un indicateur.

Kakovost vode - Določanje alkalitete - 1. del: Določanje celotne in sestavljene alkalitete (hidroksilne in del karbonatne) (ISO 9963-1:1994)

General Information

• Status: Published
• Publication Date: 12-Dec-1995
• Withdrawal Date: 29-Jun-1996
• ICS: 13.060.30 - Sewage water
• Technical Committee: CEN/TC 230 - Water analysis
• Drafting Committee: CEN/TC 230 - Water analysis
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 21-May-2008
• Completion Date: 21-May-2008
• Ref Project: SIST EN ISO 9963-1:1998 - Water quality - Determination of alkalinity - Part 1: Determination of total and composite alkalinity (ISO 9963-1:1994)

Relations

• Child: EN ISO 9963-2:1995 - Water quality - Determination of alkalinity - Part 2: Determination of carbonate alkalinity (ISO 9963-2:1994)
• Effective Date: 22-Dec-2008

Overview

EN ISO 9963-1:1995 is an internationally recognized standard published by CEN that details a precise method for determining the alkalinity of water. Known as "Water quality - Determination of alkalinity - Part 1: Determination of total and composite alkalinity", this standard specifies the titrimetric procedure for measuring alkalinity in natural, treated, and waste waters. It is designed for waters with alkalinity concentrations up to 20 mmol/L, with provisions for analyzing higher concentration samples by adjusting the test portion size. The method sets a minimum recommended detection limit of 0.4 mmol/L.

This standard supports water quality monitoring through a reliable, reproducible chemical analysis method, crucial for environmental monitoring, water treatment, and wastewater management.

Key Topics

• Scope and Applicability: Applicable to natural, treated, and wastewater analysis with alkalinity up to 20 mmol/L, adaptable to higher concentrations.
• Definition of Alkalinity: Alkalinity is defined as the quantitative capacity of water to neutralize hydrogen ions (H⁺), primarily influenced by carbonate, bicarbonate, and hydroxide ions.
• Analytical Principle: Utilizes titration of water samples with standardized hydrochloric acid to specific pH endpoints (pH 8.3 and pH 4.5), identified potentiometrically or visually using bromocresol green-methyl red indicator.
• Endpoints Explained:
  • pH 8.3 endpoint measures composite (or phenolphthalein) alkalinity, reflecting hydroxide and half carbonate content.
  • pH 4.5 endpoint measures total alkalinity, representing the neutralization of all basic components.
• Sample Preparation and Handling: Recommendations include sample collection in clean bottles, storing in cool conditions, and filtering turbid samples to reduce interference.
• Reagents and Equipment: Specifies use of analytical grade reagents such as standardized hydrochloric acid solutions, phenolphthalein indicator, and bromocresol green-methyl red indicators; equipment includes magnetic stirrers, pH meters, precise burettes, and volumetric glassware.
• Calculation and Reporting: Provides formulas to calculate alkalinity concentrations in mmol/L of hydrogen ions, with instructions on expressing results and documenting any deviations or observations.

Applications

This standard is critical for a wide range of water quality assessment and regulatory scenarios:

• Environmental Monitoring: Determining alkalinity in rivers, lakes, and groundwaters to assess buffering capacity against acidification.
• Wastewater Treatment: Monitoring treatment efficiency by measuring alkalinity in influents and effluents, supporting process control.
• Drinking Water Quality: Ensuring alkalinity levels meet health and aesthetic criteria for potable water systems.
• Industrial Water Usage: Assessing water used in processes such as cooling or boiler feed to prevent corrosion and scaling.
• Research and Laboratories: Providing a validated method for academic and professional water chemistry studies.

Related Standards

To complement the methodology and ensure comprehensive water quality analysis, users should consider related ISO and IEC standards:

• EN ISO 9963-2: Specifies determination of carbonate alkalinity.
• ISO 5667 series: Guidelines on water sampling procedures to ensure representative and uncontaminated samples.
• ISO 6107-2: Standardizes water quality vocabulary, clarifying terminology related to alkalinity.
• ISO 3696: Covers quality requirements for water used in analytical laboratories to avoid measurement interference.
• IEC 746-2: Provides guidance on the performance and calibration of pH meters for accurate endpoint detection.

Conclusion

EN ISO 9963-1:1995 establishes a standardized titrimetric method critical for determining total and composite alkalinity in diverse water samples. Its precise protocol, combining potentiometric and visual endpoint detection, ensures reliable, repeatable measurements essential for water quality management. Implementing this standard facilitates compliance with environmental regulations, supports effective water treatment practices, and advances the accurate assessment of aquatic ecosystem health.

Keywords: EN ISO 9963-1, water quality, alkalinity determination, titrimetric method, total alkalinity, composite alkalinity, water analysis, pH titration, water treatment, environmental monitoring.

Standards Content (Sample)

SLOVENSKI STANDARD
01-januar-1998
.DNRYRVWYRGH'RORþDQMHDONDOLWHWHGHO'RORþDQMHFHORWQHLQVHVWDYOMHQH
DONDOLWHWHKLGURNVLOQHLQGHONDUERQDWQH,62
Water quality - Determination of alkalinity - Part 1: Determination of total and composite
alkalinity (ISO 9963-1:1994)
Wasserbeschaffenheit - Bestimmung der Alkalinität - Teil 1: Bestimmung der gesamten
und der zusammengesetzten Alkalinität (ISO 9963-1:1994)
Qualité de l'eau - Détermination de l'alcalinité - Partie 1: Détermination de l'alcalinité
totale et composite (ISO 9963-1:1994)
Ta slovenski standard je istoveten z: EN ISO 9963-1:1995
ICS:
13.060.50 3UHLVNDYDYRGHQDNHPLþQH Examination of water for
VQRYL chemical substances
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL
IS0
STANDARD
9963-1
First edition
1994-l l-l 5
Water quality - Determination of
alkalinity -
Part 1:
Determination of total and composite alkalinity
Qua/it6 de I’eau
- D&termination d& I’alcahit6 - .
Par-tie I: D6terminatl’on de I’alcalinit6 totale et composite
Reference number
IS0 9963-l : 1994(E)
IS0 9963-l : 1994(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
technical committees. Each member body interested in a subject for
which a technical committee has been established has the right to be
represented on that committee. International organizations, governmental
and non-governmental, in liaison with ISO, also take part in the work. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard IS0 9963-l was prepared by Technical Committee
ISOnC 147, Water quality, Subcommittee SC 2, Physical, chemical,
biochemical methods.
IS0 9963 consists of the following parts, under the general title INater
quality - Determination of alkalinity
- Part I: Determination of total and composite alkalinity
- Part 2: Determination of carbonate alkalinity
Annex A of this part of IS0 9963 is for information only.
0 IS0 1994
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
ii
IS0 9963=1:1994(E)
INTERNATIONAL STANDARD 0 ISO
- Determination of alkalinity -
Water quality
Part 1:
Determination of total and composite alkalinity
IS0 5667-l : 1980, Water quality - Sampling -
1 Scope
Part 1: Guidance on the design of sampling pro-
grammes.
This part of IS0 9963 specifies a method for the
titrimetric determination of alkalinity. It is intended for
IS0 5667-2:1991, Water quality - Sampling -
the analysis of natural and treated water, and waste
Part 2: Guidance on sampling techniques.
water, and can be used directly for waters having an
alkalinity concentration of up to 20 mmol/l. For sam-
IS0 6107-2:1989, Water quality - Vocabulary -
ples containing higher concentrations of alkalinity, a
Part 2.
smaller test portion can be used for analysis. The
recommended lower limit is 0,4 mmol/l. Suspended
IEC 746-2:1982, Expression of performance of
matter in the form of carbonate may interfere with the
electrochemical analyzers - Part 2: pH Value.
analysis. This interference can be reduced by filtration
prior to the titration.
3 Definitions
The endpoint detection, using a pH-meter, is less
prone to interferences than the use of the indicator.
For the purposes of this part of IS0 9963, the follow-
ing definitions apply.
3.1 alkalinity (A): The quantitative capacity of
aqueous media to react with hydrogen ions.
2 Normative references
[ISO 6107-21
The following standards contain provisions which,
3.2 methyl red (methyl orange) endpoint alka-
through reference in this text, constitute provisions linity: An arbitrary measurement of the total alkalinity
of this part of IS0 9963. At the time of publication, the
(AT) of water obtained by titration to the methyl red
editions indicated were valid. All standards are subject
(methyl orange) indicator endpoint (pH 4,5); to assess
to revision, and parties to agreements based on this
the equivalent hydrogen carbonate, carbonate and
part of IS0 9963 are encouraged to investigate the
hydroxide concentration of water.
possibility of applying the most recent editions of the
standards indicated below. Members of IEC and IS0 3.3 phenolphthalein endpoint alkalinity; com-
maintain registers of currently valid International posite alkalinity (Ap): The measurement by titration
Standards. to the phenolphthalein endpoint (pH 8,3) of that por-
tion of alkalinity arbitrarily attributed to all the hydroxyl
IS0 385-l :I 984, Laboratory glassware - Burettes -
and half the carbonate content of a water.
Part ? : General requirements.
[ISO 6107-21
I SO 3696: 1987, Water for analytical labora tory use -
NOTE 1 The alkalinity of water is primarily a function of
the hydrogen carbonate, carbonate and hydroxide concen-
Specification and test methods.
0 IS0
IS0 9963-l : 1994(E)
trations. Other buffering substances (X) such as ammonia, 0,001 g) in water and dilute in a volumetric flask to
borate, phosphate, silicate and organic anions may be in-
1 000 ml.
cluded in the determination.
This solution is stable for at least one month if stored
A, = c(CO$-) - c(CO,aq) + c(OH-) - c(H+) + C(X)
in a refrigerator at 4 “C and 8 “C.
AT z 2c(CO;-) + c(HC0,) + c(OH-) - c(H+) + c(X)
5.3 Hydrochloric acid, c(HCI) = 0,lO mol/l.
By definition, composite alkalinity is zero for waters which
have a pH value of 8,3 or less.
hydrochloric acid
Dilute 8,6 ml + 0,l ml of
(1 ,I 6 g/ml) to 1 >OO ml with water. Standardize this
solution as follows, using either potentiometric
4 Principle
(5.3.1) or visual endpoint detection (5.3.2).
The sample is titrated with standard acid solution to
5.3.1 Potentiometric detection.
fixed pH endpoint values of 8,3 and 4,5. These
which are determined visually or
endpoints,
Pipette 25,0 ml + 0,l ml (VI) of the sodium
are the selected equivalence
potentiometrically,
carbonate solution(5.2) into a titration vessel and add
points for the determinations of the three principal
75 ml + 5 ml of water (5.1). Place the vessel on a
-
components: hydrogen carbonate, carbonate and hy-
magnetic stirrer and dip into the solution a plastics-
droxide. The pH 8,3 endpoint approximates to the
coated magnetic stirrer bar and electrodes previously
equivalent concentrations of carbonate and carbon di-
connected to a calibrated pH-meter. Start the stirrer
oxide and represents the titration of approximately all
and stir at a rate at which a vortex is just not
the hydroxide and half of the carbonate present. The
perceptible. Titrate with OJO mol/l hydrochloric acid
pH 4,5 endpoint approximates the equivalence point
solution (5.3) until the meter reads pH 4,5 + 0,05.
for hydrogen ion and hydrogen carbonate and allows
Note the volume V2, in millilitres, of acid consumed.
for the determination of the total alkalinity of the
sample.
5.3.2 Visual endpoint detection.
NOTE 2 The equivalent point values depend on the ionic
Pipette 25,0 ml + 0,l ml (VI) of approximately
strength as well as the concentration of total inorganic car-
0,025 mol/l sodium carbonate solution (5.2) into a
bon and may not always be optimum at the chosen
endpoints. 250 ml Erlenmeyer flask, and add 75 ml + 5 ml of
-
water and 0,l ml + 0,02 ml of bromocresol green-
Whilst methyl orange and methyl red have been commonly
methyl red indicator solution (5.6). Titrate with
used in the past as indicators for the determination of total
0,lO mol/l hydrochloric acid solution (5.3) until the
alkalinity, in practice the use of different indicator systems
greenish-blue colour disappears. Note the volume V2,
produce slightly different results in alkalinity titrations. For
in millilitres, of acid consumed.
alkalinity determinations in accordance with this part of
IS0 9963, the correct bromocresol green-methyl red indi-
cator solution as defined in 5-6 should be used.
5.3.3 Blank determination.
Using 100 ml + 5 ml of water, carry out a blank de-
5 Reagents
termination according to the appropriate procedure
(5.3.1 or 5.3.2) and note the
...