EN 890:2012

SLOVENSKI STANDARD
01-september-2012
1DGRPHãþD
SIST EN 890:2005
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Chemicals used for treatment of water intended for human consumption - Iron (III)
sulfate, liquid
Produkte zur Aufbereitung von Wasser für den menschlichen Gebrauch - Eisen(III)sulfat,
flüssig
Produits chimiques utilisés pour le traitement de l'eau destinée à la consommation
humaine - Sulfate de fer (III) liquide
Ta slovenski standard je istoveten z: EN 890:2012
ICS:
13.060.20 Pitna voda Drinking water
71.100.80 .HPLNDOLMH]DþLãþHQMHYRGH Chemicals for purification of
water
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 890
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2012
ICS 71.100.80 Supersedes EN 890:2004
English Version
Chemicals used for treatment of water intended for human
consumption - Iron (III) sulfate solution
Produits chimiques utilisés pour le traitement de l'eau Produkte zur Aufbereitung von Wasser für den
destinée à la consommation humaine - Sulfate de fer (III) menschlichen Gebrauch - Eisen(III)sulfat-Lösung
liquide
This European Standard was approved by CEN on 24 May 2012.

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 bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC 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 translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 890:2012: E
worldwide for CEN national Members.

Contents
Page
Foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Description . 6
3.1 Identification . 6
3.2 Commercial forms . 7
3.3 Physical properties . 7
3.4 Chemical properties . 8
4 Purity criteria . 8
4.1 General . 8
4.2 Composition of commercial product . 8
4.3 Impurities and main by-products . 8
4.4 Chemical parameters . 9
5 Test methods . 9
5.1 Sampling . 9
5.2 Analyses . 10
6 Labelling − Transportation − Storage . 12
6.1 Means of delivery . 12
6.2 Labelling according to the EU Legislation . 13
6.3 Transportation regulations and labelling . 13
6.4 Marking . 14
6.5 Storage . 14
Annex A (informative) General information on iron (III) sulfate solution . 15
A.1 Origin . 15
A.1.1 Raw materials . 15
A.1.2 Manufacturing process . 15
A.2 Quality of commercial product . 15
A.3 Use . 19
A.3.1 Function . 19
A.3.2 Form in which it is used . 19
A.3.3 Treatment dose . 19
A.3.4 Means of application . 19
A.3.5 Secondary effects . 19
A.3.6 Removal of excess product . 19
Annex B (normative) Analytical methods . 20
B.1 Determination of iron (III) sulfate . 20
B.1.1 Total iron . 20
B.1.2 Determination of iron (II) ( Fe (II)) . 21
B.1.3 Determination of iron (III) ( Fe (III)) . 22
B.2 Determination of manganese . 22
B.2.1 General . 22
B.2.2 Principle . 22
B.2.3 Reagents . 22
B.2.4 Apparatus . 23
B.2.5 Procedure . 23
B.3 Determination of insoluble matters . 24
B.3.1 General . 24
B.3.2 Principle . 24
B.3.3 Reagents . 24
B.3.4 Apparatus . 24
B.3.5 Procedure . 25
B.3.6 Calculation . 25
B.3.7 Precision . 25
B.4 Determination of free acid . 25
B.4.1 General. 25
B.4.2 Principle . 25
B.4.3 Interferences . 26
B.4.4 Reagents . 26
B.4.5 Apparatus . 26
B.4.6 Procedure . 26
B.4.7 Calculation . 26
B.5 Determination of arsenic, antimony and selenium by hydride generation atomic absorption
spectrometry (AAS) . 27
B.5.1 General. 27
B.5.2 Principle . 27
B.5.3 Reagents . 27
B.5.4 Apparatus . 28
B.5.5 Procedure . 28
B.6 Determination of mercury by cold vapour atomic absorption spectrometry (AAS) . 30
B.6.1 General. 30
B.6.2 Principle . 31
B.6.3 Reagents . 31
B.6.4 Apparatus . 31
B.6.5 Procedure . 32
B.7 Determination of cadmium, chromium, nickel and lead by graphite furnace atomic absorption
spectrometry (AAS) . 32
B.7.1 General. 32
B.7.2 Principle . 33
B.7.3 Reagents . 33
B.7.4 Apparatus . 33
B.7.5 Procedure . 34
Annex C (informative) Reduction of Fe (III) on a silver column. 36
C.1 General. 36
C.2 Principle . 36
C.3 Reagents . 36
C.4 Apparatus . 36
C.5 Procedure . 36
C.5.1 Preparation of the silver powder . 36
C.5.2 Reduction of Fe (III) . 37
Annex D (informative) Determination of cadmium, chromium, nickel and lead (inductively coupled
plasma optical emission spectrometry (ICP/OES)) . 38
D.1 General. 38
D.2 Principle . 38
D.3 Reagents . 38
D.4 Apparatus . 39
D.5 Procedure . 39
D.5.1 Spectrometer settings . 39
D.5.2 Calibration, measurement and calculation of the elements cadmium, chromium, nickel and
lead . 39
Annex E (normative) General rules relating to safety . 40
E.1 Rules for safe handling and use . 40
E.2 Emergency procedures . 40
E.2.1 First aid . 40
E.2.2 Spillage . 40
E.2.3 Fire . 40
Bibliography . 41

Foreword
This document (EN 890:2012) 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 January 2013, and conflicting national standards shall be withdrawn at the latest
by January 2013.
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.
This document supersedes EN 890:2004.
Significant technical differences between EN 890:2012 and EN 890:2004 are as follows:
a) change of the maximum allowed percentage of mass fraction of insoluble matter in the product from 0,3 % to
0,5 % (see Table 2);
b) update of the information of risk and safety labelling of the product to comply with the new regulations (see 6.2
and [2]);
c) change of the method for determination of iron (III) sulfate in order to avoid the use of hazardous potassium
dichromate (see B.1).
According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.

Introduction
In respect of potential adverse effects on the quality of water intended for human consumption, caused by the
product covered by this document:
a) this 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;
b) it should be noted that, while awaiting the adoption of verifiable European criteria, existing national regulations
concerning the use and/or the characteristics 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.
1 Scope
This European Standard is applicable to iron (III) sulfate solution of various iron and/or acid contents (see 3.2) used
for treatment of water intended for human consumption. It describes the characteristics of iron (III) sulfate solution
and specifies the requirements and the corresponding analytical methods for iron (III) sulfate solution (analytical
methods are given in Annex B) and gives information on its use in water treatment. It also determines the rules
relating to safe handling and use of iron (III) sulfate solution (see Annex E).
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable
for its application. For dated references, only the edition cited applies. For undated references, the latest edition of
the referenced document (including any amendments) applies.
EN 10028-7, Flat products made of steels for pressure purposes ― Part 7: Stainless steels
EN 10088-1, Stainless steels ― Part 1: List of stainless steels
EN ISO 3696, Water for analytical laboratory use ― Specification and test methods (ISO 3696)
ISO 3165, Sampling of chemical products for industrial use ― Safety in sampling
ISO 5790:1979, Inorganic chemical products for industrial use ― General method for determination of chloride
content ― Mercurimetric method
ISO 6206, Chemical products for industrial use ― Sampling ― Vocabulary
3 Description
3.1 Identification
3.1.1 Chemical name
Iron (III) sulfate, solution.
3.1.2 Synonym or common names
Ferric sulfate liquor, red iron liquor.
3.1.3 Relative molecular mass
399,87.
3.1.4 Empirical formula
Fe (SO ) .
2 4 3
3.1.5 Chemical formula
Fe (SO ) .
2 4 3
1)
3.1.6 CAS Registry Number
10028-22-5.
1) Chemical Abstract Service Registry Number.
2)
3.1.7 EINECS reference
233-072-9.
3.2 Commercial forms
Different classes of solution exist varying in iron content and acidity. Examples are given in Table 1.
Table 1 — Different classes
Fe (SO ) Free H SO
Classes Fe (III) Density at 15 °C
2 4 3 2 4
c
Mass fraction Mass fraction g/ml
Mass fraction
in % in %
in %
Class A 11,20 to 11,80 40,00 to 42,14 < 1,00 1,49 to 1,53
a
Class B 11,20 to 11,80 36,10 to 39,24 1,45 to 1,47
Class C 8,40 to 8,80 30,00 to 31,43 10,00 to 11,00 1,46 to 1,48
Class D 12,50 to 12,80 44,60 to 45,70 < 1,00 1,57 to 1,60
a
Class E 12,50 to 12,80 40,70 to 42,80 1,52 to 1,56
b
Class F 13,50 to 14,00 44,78 to 47,55 1,58 to 1,63
a 2-
Deficiency of SO , expressed as H SO , is a mass fraction of 3 % to 4 % of the product.
4 2 4
b 2-
Deficiency of SO , expressed as H SO , is a mass fraction of 2,5 % to 3,5 % of the product.
4 2 4
c 2-
Fe (SO ) by direct stoichiometry with subtraction of calculated SO deficiency where appropriate on classes B, E and F.
2 4 3 4
3.3 Physical properties
3.3.1 Appearance
The iron (III) sulfate solution is a red/brown solution.
3.3.2 Density
See Table 1.
3.3.3 Solubility (in water)
The iron (III) sulfate solution is dilutable down to about a mass fraction of 1 % of Fe (SO ) . Below this
2 4 3
concentration, hydrolysis and formation of hydroxide will occur.
3.3.4 Vapour pressure
Not known.
3)
3.3.5 Boiling point at 100 kPa
Higher than 100 °C.
3.3.6 Freezing point
Lower than - 15 °C.
2) European Inventory of Existing Commercial Chemical Substances.
3) 100 kPa = 1 bar.
3.3.7 Specific heat
Not known.
3.3.8 Viscosity (dynamic)
The viscosity of the commonly used solution varies in the range of 5 mPa.s to 130 mPa.s at 10 °C.
3.3.9 Critical temperature
Not applicable.
3.3.10 Critical pressure
Not applicable.
3.3.11 Physical hardness
Not applicable.
3.4 Chemical properties
The solutions of iron (III) sulfate are acidic.
4 Purity criteria
4.1 General
This document specifies the minimum purity requirements for iron (III) sulfate solution 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 may be present and, if so, this shall
be notified to the user and when necessary to relevant authorities.
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 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 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 commercial product
The product shall contain not less than a mass fraction of 30 % of Fe (SO ) and shall be within ± 3 % of the
2 4 3
manufacturer's declared values.
4.3 Impurities and main by-products
The product shall conform to the requirements specified in Table 2.
The concentration limits refer to Fe (III).
Table 2 — Impurities
Impurity Limit
Mass fraction of Fe (III) content
%
Grade 1 Grade 2 Grade 3
Manganese max. 0,5 1 2
a
max. 2,5 2,5 2,5
Iron (II)
b
max. 0,5 0,5 0,5
Insoluble matters
a
Fe (II) has a lower coagulant efficiency compared to Fe (III). Also hydrolysis of
Fe (II) starts at pH value 8, and therefore Fe (II) can remain into the water at lower

pH values.
b
An excess of insoluble matters indicates the presence of foreign matter (see
A.2). Iron is a component of the product that will usually be removed in the

treatment process.
4.4 Chemical parameters
The product shall conform to the requirements specified in Table 3.
The concentration limits are specified in milligrams per kilogram of Fe (III).
Table 3 ― Chemical parameters
Limit in
Parameter
mg/kg of Fe (III)
Type 1 Type 2 Type 3
Arsenic (As) max. 1 20 50
Cadmium (Cd) max. 1 25 50
Chromium (Cr) max. 100 350 500
Mercury (Hg) max. 0,1 5 10
Nickel (Ni) max. 300 350 500
Lead (Pb) max. 10 100 400
Antimony (Sb) max. 10 20 60
Selenium (Se) max. 1 20 60
-
NOTE Cyanide (CN ), pesticides and polycyclic aromatic hydrocarbons are
not relevant since the raw materials used in the manufacturing process are free of
them. For maximum impact of iron (III) sulfate on trace metal content in drinking
water see A.2.
5 Test methods
5.1 Sampling
5.1.1 General
Observe the general recommendations in ISO 3165 and take into account ISO 6206. Prepare the laboratory
sample required by the relevant procedure described in 5.1.2 and 5.1.3.
5.1.2 Sampling from drums and bottles
5.1.2.1 General
5.1.2.1.1 Mix the contents of each container to be sampled by shaking the container, by rolling it or by rocking it
from side to side, taking care not to damage the container or spill any of the liquid.
5.1.2.1.2 If the design of the container is such (for example, a narrow-necked bottle) that it is impracticable to
use a sampling implement, take a sample by pouring after the contents have been thoroughly mixed. Otherwise,
proceed as described in 5.1.2.3.
5.1.2.1.3 Examine the surface of the liquid. If there are signs of surface contamination, take samples from the
surface as described in 5.1.2.2. Otherwise, take samples as described in 5.1.2.3.
5.1.2.2 Surface sampling
Take a sample using a suitable ladle. Lower the ladle into the liquid until the rim is just below the surface, so that
the surface layer runs into it. Withdraw the ladle just before it fills completely and allow any liquid adhering to the
ladle to drain off. If necessary, repeat this operation so that, when the other selected containers have been
sampled in a similar manner, the total volume of sample required for subsequent analysis is obtained.
5.1.2.3 Bottom sampling
Take a sample using an open sampling tube, or a bottom-valve sampling tube, suited to the size of container and
the viscosity of the liquid.
When using an open sampling tube, close it at the top and then lower the bottom end to the bottom of the
container. Open the tube and move it rapidly so that the bottom of the tube traverses the bottom of the container
before the tube is filled. Close the tube, withdraw it from the container and allow any liquid adhering at the outside
of the tube to drain off.
When using a bottom-valve sampling tube, close the valve before lowering the tube into the container and then
proceed in a similar manner to that when using an open sampling tube.
5.1.3 Sampling from tanks and tankers
From each access point, take samples as follows:
a) from the surface of the liquid, using a ladle as described in 5.1.2.2;
b) from the bottom of the tank or tanker, using a sampling tube as described in 5.1.2.3 or using specially
designed bottom-sampling apparatus;
c) from one or more positions, depending on the overall depth, between the bottom and the surface using a
weighted sampling can.
5.2 Analyses
5.2.1 Main product
Iron (III) sulfate is determined as Fe (III) contents in the test sample. Fe (III) content is determined as the difference
between total iron content and Fe (II) content (see B.1).
5.2.2 Impurities
5.2.2.1 Manganese
The manganese content shall be determined by flame atomic absorption spectrometry (FAAS) (see B.2).
5.2.2.2 Iron (II) ( Fe (II))
The Fe (II) content is expressed as C(II) (see B.1.2.5.3).
5.2.2.3 Insoluble matters
The percentage mass fraction of the insoluble matters shall be determined in accordance with the method
described in B.3.
5.2.2.4 Free acid
The free acid shall be determined in accordance with the method described in B.4.
5.2.3 Chemical parameters
5.2.3.1 Preparation of sample solution
5.2.3.1.1 General
Oxidation and wet digestion is used to bring the samples into a stable solution.
5.2.3.1.2 Principle
)
Oxidation with hydrogen peroxide (H O followed by digestion with hydrochloric acid (HCl).
2 2
5.2.3.1.3 Reagents
All reagents shall be of a recognized analytical grade and the water used shall conform to the grade 3 specified in
EN ISO 3696.
5.2.3.1.3.1 Hydrochloric acid (HCl), solution, mass fraction 30 %.
5.2.3.1.3.2 Hydrogen peroxide (H O ), solution, mass fraction 30 %.

2 2
5.2.3.1.4 Apparatus
Ordinary laboratory apparatus and glassware together with the following.
5.2.3.1.4.1 Analytical balance.
5.2.3.1.4.2 Graduated cylinder, capacity 50 ml.
5.2.3.1.4.3 Round flask with reflux condenser.
5.2.3.1.4.4 Hot plate.
5.2.3.1.4.5 Volumetric flask, capacity 200 ml.
5.2.3.1.5 Procedure
Dissolve with 20 ml of water 20,0 g of the iron solution. Add 5 ml hydrogen peroxide solution (5.2.3.1.3.2) to iron
(III)-samples. After adding 50 ml hydrochloric acid (5.2.3.1.3.1) boil the solution for 15 min by using a reflux
condenser (5.2.3.1.4.3). Cool down the solution, transfer to a 200 ml volumetric flask (5.2.3.1.4.5) and fill up to the
mark with water. This is the sample solution.
5.2.3.2 Arsenic
The arsenic content shall be determined by hydride generation atomic absorption spectrometry (see B.5).
5.2.3.3 Cadmium
The cadmium content shall be determined by graphite furnace atomic absorption spectrometry (see B.7) or by
inductively coupled plasma optical emission spectrometry (see Annex D).
5.2.3.4 Chromium
The chromium content shall be determined by graphite furnace atomic absorption spectrometry (see B.7) or by
inductively coupled plasma optical emission spectrometry (see Annex D).
5.2.3.5 Mercury
The mercury content shall be determined by cold vapour atomic absorption spectrometry (see B.6).
5.2.3.6 Nickel
The nickel content shall be determined by graphite furnace atomic absorption spectrometry (see B.7) or by
inductively coupled plasma optical emission spectrometry (see Annex D).
5.2.3.7 Lead
The lead content shall be determined by graphite furnace atomic absorption spectrometry (see B.7) or by
inductively coupled plasma optical emission spectrometry (see Annex D).
5.2.3.8 Antimony
The antimony content shall be determined by hydride generation atomic absorption spectrometry (see B.5).
5.2.3.9 Selenium
The selenium content shall be determined by hydride generation atomic absorption spectrometry (see B.5).
6 Labelling − Transportation − Storage
6.1 Means of delivery
The product shall be delivered in stainless steel road tankers and plastics containers.
In order that the purity of the product is not affected, the means of delivery shall not have been used previously for
any different product or it shall have been specially cleaned and prepared before use.
4)
6.2 Labelling according to the EU Legislation
The following labelling requirements shall apply to iron (III) sulfate solution at the date of the publication of this
standard:
Optional up to 31/05/2015, obligatory thereafter [2]. Optional up to 31/05/2015 [3].
- Labels - Labels
Figure 1 — GHS05   Figure 2 — GHS07 Figure 3 — C      Figure 4 — Xn

- Signal words: - Danger symbols:
GHS05: Warning C: Corrosive
GHS07: Warning Xn: Harmful
- Hazard statements - Risk phrases:
H290: May be corrosive to metal R 22: Harmful if swallowed
H302: Harmful if swallowed R 34: Causes burns
H319: Causes serious eye irritation
NOTE 1: Precautionary statements ('P statements') should be provided
by the company being responsible for the marketing of the substance.
They should be indicated on the packaging label and in the extended
safety data sheet (eSDS) of the substance.

NOTE 2: The legislation [2] (or [3]), and its amendments for the purposes of its adaptation to technical and scientific progress, contains a list
of substances classified by the EU. Substances not listed in this regulation should be classified on the basis of their intrinsic properties
according to the criteria in the regulation by the person responsible for the marketing of the substance.
6.3 Transportation regulations and labelling
5)
Iron (III) sulfate solution is listed as UN number : 1760.

4) See [2] and [3].
5) United Nations Number.
6) 7)
ADR / RID : Class 8; classification code C9; packing group I
8)
IMDG : Class 8, Packing group I. IMDG page 8134.
9)
IATA : Class 8, Packing group I.
6.4 Marking
The marking shall include the following information:
 the name "iron (III) sulfate water solution", trade name, class, grade and type;
 the net mass;
 the name and the address of the supplier and/or manufacturer;
 the statement "this product conforms to EN 890".
6.5 Storage
6.5.1 Long term stability
Storable in stainless steel conforming to EN 10028-7 and EN 10088-1 (grades 1.44xx) , rubber and most plastics
containers or tanks.
Some sedimentation of yellow iron (III) sulfate can occur. To avoid problems caused by sedimentation of iron (III)
sulfate, storage tanks should be cleaned every 1 to 2 years.
6.5.2 Storage incompatibilities
Iron (III) sulfate solution is corrosive :
 avoid contact with metals (except the stainless steel specified in 6.5.1);
 avoid contact with alkalis;
 avoid contact with oxidizing agents especially chlorites and hypochlorites.

6) European Agreement concerning the international carriage of Dangerous goods by Road.
7) Regulations concerning International carriage of Dangerous goods by rail.
8) International Maritime transport of Dangerous Goods.
9) International Air Transport Association.
Annex A
(informative)
General information on iron (III) sulfate solution
A.1 Origin
A.1.1 Raw materials
The product is manufactured from an iron source, typically iron (II) sulfate or an iron oxide, which is reacted with a
combination of sulfuric acid and an oxidising agent, such as nitric acid, oxygen, hydrogen peroxide or air, at
elevated temperature or pressure.
A.1.2 Manufacturing process
Iron (III) sulfate is produced by the action of sulfuric acid on a variety of iron salts or ores in combination with an
oxidation process as required.
A.2 Quality of commercial product
The three types of iron (III) sulfate solution specified in Table 3 reflect the quality of commercially available
products. Figures A.1 to A.3 show the maximum concentrations of trace metals that would be added to the raw
water by the addition of products corresponding to the purity levels specified in Table 3. It can be seen that the
concentrations of metal added are well below the parametric values given in the EU Directive 98/83/EC (see [1]) at
typical product doses. Furthermore, the figures overstate the concentration of metals that would be present in the
treated water since a substantial proportion of the trace metals will be incorporated in the sludge. Users of this
product should select an appropriate grade and type to enable them to achieve treated water quality targets taking
into account raw water characteristics, required dosage, process plant conditions and other relevant factors.
The maximum allowed percentage of mass fraction of insoluble matter in the product presented in Table 2 (i.e.
0,5 %) does not affect adversely the water quality. On the contrary, insoluble matter in the product improves the
coagulation process and might therefore enhance the treatment.

Key
1 maximum metal addition to water µg/l
2 product dosage mg/l Fe – Typical dose
A element
B drinking water limit µg/l
Figure A.1 — Maximum impact of iron (III) sulfate solution, type 1, on trace metal content of water

Key
1 maximum metal addition to water µg/l
2 product dosage mg/l Fe – Typical dose
A element
B drinking water limit µg/l
Figure A.2 — Maximum impact of iron (III) sulfate solution, type 2, on trace metal content of water

Key
1 maximum metal addition to water µg/l
2 product dosage mg/l Fe – Typical dose
A element
B drinking water limit µg/l
Figure A.3 — Maximum impact of iron (III) sulfate solution, type 3, on trace metal content of water

A.3 Use
A.3.1 Function
The product is used as primary coagulant.
A.3.2 Form in which it is used
The product is used as delivered or diluted.
A.3.3 Treatment dose
The treatment dose is variable depending on raw water quality and corresponds to a treatment dose between
3 3
4 g/m and 10 g/m expressed as Fe.
A.3.4 Means of application
The product can be dosed as delivered by acid resistant pumps. To promote a rapid dispersion a high turbulence at
the point of addition and dilution with carrier water is desirable.
A.3.5 Secondary effects
Increase of the sulfate content. Reduction of alkalinity and pH value.
A.3.6 Removal of excess product
The coagulation process includes the hydrolysis of the ferric ions to ferric hydroxide. This precipitate is removed by
sedimentation, flotation and/or finally filtration.
Annex B
(normative)
Analytical methods
B.1 Determination of iron (III) sulfate
B.1.1 Total iron
B.1.1.1 General
This method applies to the products at the supply concentration.
B.1.1.2 Principle
Iron is reduced by tin (II) chloride and is subsequently titrated with ceric sulfate.
B.1.1.3 Reagents
All reagents shall be of a recognized analytical grade and the water used shall conform to the grade 3 in
accordance with EN ISO 3696.
B.1.1.3.1 Hydrochloric acid, HCl concentrated, density ρ = 1,19 g/ml.
B.1.1.3.2 Tin (II) chloride solution, c(SnCl .2H O) = 0,5 mol/l.
2 2
Dissolve 22,6 g of SnCl . 2H O with 20 ml of hydrochloric acid (B.1.1.3.1) and dilute with water to 200 ml. Keep
2 2
this solution in the dark.
B.1.1.3.3 Mercury (II) chloride, saturated solution c(HgCl ) = 0,27 mol/l.
B.1.1.3.4 Ferroin indicator (i.e. 1,10-phenantroline ferrous sulfate) solution, 1 % w/v in water.
B.1.1.3.5 Ceric sulfate, c(Ce(SO ) = 0,1 mol/l.
4 2
B.1.1.4 Apparatus
Ordinary laboratory apparatus and glassware.
B.1.1.5 Procedure
B.1.1.5.1 Test solution
Weigh, to the nearest 0,1 mg, 10 g of the laboratory sample and transfer to a 200 ml volumetric flask, dilute to the
mark with water. Pipette 10 ml and transfer
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