CEN ISO/TS 21268-3:2009

SLOVENSKI STANDARD
01-februar-2010
Kakovost tal - Postopki izluževanja za nadaljnje kemijsko in ekotoksikološko
preskušanje tal in talnih (zemeljskih) materialov - 3. del: Preskus v koloni s tokom
navzgor (ISO/TS 21268-3:2007)
Soil quality - Leaching procedures for subsequent chemical and ecotoxicological testing
of soil and soil materials - Part 3: Up-flow percolation test (ISO/TS 21268-3:2007)
Bodenbeschaffenheit - Eluierungsverfahren für die anschließende chemische und
ökotoxikologische Untersuchung von Boden und von Bodenmaterialien - Teil 3:
Perkolationstest im Aufwärtsstrom (ISO/TS 21268-3:2007)
Qualité du sol - Modes opératoires de lixiviation en vue d'essais chimiques et
écotoxicologiques ultérieurs des sols et matériaux du sol - Partie 3: Essai de percolation
à écoulement ascendant (ISO/TS 21268-3:2007)
Ta slovenski standard je istoveten z: CEN ISO/TS 21268-3:2009
ICS:
13.080.05 Preiskava tal na splošno Examination of soils in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL SPECIFICATION
CEN ISO/TS 21268-3
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
November 2009
ICS 13.080.05
English Version
Soil quality - Leaching procedures for subsequent chemical and
ecotoxicological testing of soil and soil materials - Part 3: Up-
flow percolation test (ISO/TS 21268-3:2007)
Qualité du sol - Modes opératoires de lixiviation en vue Bodenbeschaffenheit - Eluierungsverfahren für die
d'essais chimiques et écotoxicologiques ultérieurs des sols anschließende chemische und ökotoxikologische
et matériaux du sol - Partie 3: Essai de percolation à Untersuchung von Boden und von Bodenmaterialien - Teil
écoulement ascendant (ISO/TS 21268-3:2007) 3: Perkolationstest im Aufwärtsstrom (ISO/TS 21268-
3:2007)
This Technical Specification (CEN/TS) was approved by CEN on 8 September 2009 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.

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Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

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EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN ISO/TS 21268-3:2009: E
worldwide for CEN national Members.

Contents Page
Foreword .3

Foreword
The text of ISO/TS 21268-3:2007 has been prepared by Technical Committee ISO/TC 190 “Soil quality” of the
International Organization for Standardization (ISO) and has been taken over as CEN ISO/TS 21268-3:2009
by Technical Committee CEN/TC 345 “Characterization of soils” the secretariat of which is held by NEN.
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.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO/TS 21268-3:2007 has been approved by CEN as a CEN ISO/TS 21268-3:2009 without any
modification.
TECHNICAL ISO/TS
SPECIFICATION 21268-3
First edition
2007-07-15
Soil quality — Leaching procedures for
subsequent chemical and
ecotoxicological testing of soil and soil
materials
Part 3:
Up-flow percolation test
Qualité du sol — Modes opératoires de lixiviation en vue d'essais
chimiques et écotoxicologiques ultérieurs des sols et matériaux du sol
Partie 3: Essai de percolation à écoulement ascendant

Reference number
ISO/TS 21268-3:2007(E)
©
ISO 2007
ISO/TS 21268-3:2007(E)
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ii © ISO 2007 – All rights reserved

ISO/TS 21268-3:2007(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope .1
2 Normative references .1
3 Terms and definitions .2
4 Principle.3
5 Reagents and materials .4
6 Apparatus .4
7 Sample pre-treatment.5
7.1 Sample preparation .5
7.2 Particle size reduction.6
7.3 Test portion .6
7.4 Determination of dry matter content.6
8 Procedure .6
8.1 Temperature .6
8.2 Preparation .7
8.3 Packing of the column .7
8.4 Start of the test.8
8.5 Collection of additional eluate fractions .9
8.6 Further preparation of the eluates for analysis .10
8.7 Blank test.10
9 Calculations.11
10 Test report .11
11 Test performance.11
Annex A (informative) Suggestions for packing the column, water saturation and establishment
of equilibrium conditions.12
Annex B (informative) Justification of the choices made in developing the test procedure .14
Bibliography .18

ISO/TS 21268-3:2007(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
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. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. 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.
In other circumstances, particularly when there is an urgent market requirement for such documents, a
technical committee may decide to publish other types of normative document:
— an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in
an ISO working group and is accepted for publication if it is approved by more than 50 % of the members
of the parent committee casting a vote;
— an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical
committee and is accepted for publication if it is approved by 2/3 of the members of the committee casting
a vote.
An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a
further three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is
confirmed, it is reviewed again after a further three years, at which time it must either be transformed into an
International Standard or be withdrawn.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO/TS 21268-3 was prepared by Technical Committee ISO/TC 190, Soil quality, Subcommittee SC 7, Soil
and site assessment.
ISO/TS 21268 consists of the following parts, under the general title Soil quality — Leaching procedures for
subsequent chemical and ecotoxicological testing of soil and soil materials:
⎯ Part 1: Batch test using a liquid to solid ratio of 2 l/kg dry matter
⎯ Part 2: Batch test using a liquid to solid ratio of 10 l/kg dry matter
⎯ Part 3: Up-flow percolation test
⎯ Part 4: Influence of pH on leaching with initial acid/base addition

iv © ISO 2007 – All rights reserved

ISO/TS 21268-3:2007(E)
Introduction
In various countries, tests have been developed to characterise and assess the constituents which can be
released from materials. The release of soluble constituents upon contact with water is regarded as a main
mechanism of release, which results in a potential risk to the environment during the use or disposal of
materials. The intent of these tests is to identify the leaching properties of materials. The complexity of the
leaching process makes simplifications necessary.
Not all of the relevant aspects of leaching behaviour can be addressed in one standard.
Tests to characterise the behaviour of materials can generally be divided into three categories (EN 12920;
[13]
EN/TS 14405) and are addressed in ISO 18772 . The relationships between these tests are summarised
below:
a) “Basic characterisation” tests are used to obtain information on the short- and long-term leaching
behaviour and characteristic properties of materials. Liquid/solid (L/S) ratios, leachant composition,
factors controlling leachability, such as pH, redox potential, complexing capacity, role of dissolved organic
carbon (DOC), ageing of material and physical parameters, are addressed in these tests.
b) “Compliance” tests are used to determine whether the material complies with a specific behaviour or with
specific reference values. The tests focus on key variables and leaching behaviour previously identified
by basic characterisation tests.
c) “On-site verification” tests are used as a rapid check to confirm that the material is the same as that which
has been subjected to the compliance test(s). On-site verification tests are not necessarily leaching tests.
The test procedure described in this method belongs to category b): basic characterisation tests.
NOTE Up to now, the test procedure described in this part of ISO/TS 21268 has not been validated internationally.
This Technical Specification was elaborated on the basis of CEN/TS 14405.

TECHNICAL SPECIFICATION ISO/TS 21268-3:2007(E)

Soil quality — Leaching procedures for subsequent chemical
and ecotoxicological testing of soil and soil materials
Part 3:
Up-flow percolation test
1 Scope
This part of ISO/TS 21268 specifies a test, which is aimed at determining the leaching behaviour of inorganic
and organic constituents from a soil and soil material. The method is a once-through percolation test with
water (0,001 mol/l CaCl ) under standardized conditions of flow rate. The material is leached under dynamic
hydraulic conditions. The eluates obtained can be used to determine the ecological properties of the soil with
respect to micro-organisms, flora and fauna. The test results enable the distinction between different release
patterns, for instance wash-out and release under the influence of interaction with the matrix, when
approaching local equilibrium between material and leachant.
This test method produces eluates, which can subsequently be characterised by physical, chemical and
ecotoxicological methods in accordance with existing standard methods. The results of eluate analysis are
presented as a function of the liquid/solid ratio. The test is not suitable for species that are volatile under
ambient conditions.
NOTE 1 Volatile organic constituents include the low-molecular-weight components in mixtures such as mineral oil.
NOTE 2 It is not always possible to optimise test conditions simultaneously for inorganic and organic constituents and
optimum test conditions may also vary between different groups of organic constituents. Test requirements for organic
constituents are generally more stringent than those for inorganic constituents. The test conditions suitable for measuring
the release of organic constituents will generally also be applicable to inorganic constituents.
NOTE 3 For ecotoxicological testing, eluates representing the release of both inorganic and organic contaminants are
needed. In this document, ecotoxicological testing is also meant to include genotoxicological testing.
The application of this test method alone is not sufficient for the determination of the leaching behaviour of a
material under specified conditions different to those from the test procedure, since this generally requires the
application of several test methods, behavioural modelling and model validation. This part of ISO/TS 21268
does not address issues related to health and safety. It only determines the leaching properties as outlined in
Clause 4.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 5667-3, Water Quality — Sampling — Part 3: Guidance on the preservation and handling of water
samples
ISO 7027:1999, Water quality — Determination of turbidity
ISO/TS 21268-3:2007(E)
ISO 10381-1, Soil quality — Sampling — Part 1: Guidance on the design of sampling programmes
ISO 10381-2, Soil quality — Sampling — Part 2: Guidance on sampling techniques
ISO 10381-3, Soil quality — Sampling — Part 3: Guidance on safety
ISO 10381-4, Soil quality — Sampling — Part 4: Guidance on the procedure for investigation of natural, near-
natural and cultivated sites
ISO 10381-5, Soil quality — Sampling — Part 5: Guidance on the procedure for the investigation of urban and
industrial sites with regard to soil contamination
ISO 10381-6, Soil quality — Sampling — Part 6: Guidance on the collection, handling and storage of soil for
the assessment of aerobic microbial processes in the laboratory
ISO 10523, Water quality — Determination of pH
ISO 11465, Soil quality — Determination of dry matter and water content on a mass basis — Gravimetric
method
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
leaching test
test during which a material is put into contact with a leachant under strictly defined conditions and some
constituents of the material are extracted
3.2
leachant
liquid used in a leaching test
NOTE For the purposes of this part of ISO/TS 21268, the leachant is water as specified in 5.1.
3.3
eluate
solution recovered from a leaching test
3.4
liquid to solid ratio
L/S
the ratio between the total volume of liquid (L in litres), which in this extraction is in contact with the soil
sample, and the dry mass of the sample (S in kg of dry matter).
NOTE L/S is expressed in l/kg.
3.5
laboratory sample
sample or subsample(s) sent to or received by the laboratory
3.6
test sample
sample, prepared from the laboratory sample, from which test portions are removed for testing or analysis
2 © ISO 2007 – All rights reserved

ISO/TS 21268-3:2007(E)
3.7
test portion
quantity of material of appropriate size for measurement of the concentration or other properties of interest,
taken from the test sample
NOTE 1 The test portion can be taken from the laboratory sample directly if no pre-treatment of sample is required, but
usually it is taken from the test sample.
NOTE 2 A unit or increment of proper homogeneity, size and fineness, needing no further preparation, can be a test
portion.
3.8
granular material
solid material, not being monolithic
NOTE It is not a gas, a liquid or a sludge.
3.9
dry matter content
w
dm
ratio expressed in percent between the mass of the dry residue and the corresponding raw mass
NOTE It is determined in accordance with ISO 11465.
3.10
soil materials
excavated soil, dredged materials, manufactured soils, treated soils and fill materials
[ISO 15176:2002, definition 3.1.4]
4 Principle
This part of ISO/TS 21268 describes a method to determine the release of constituents from soil and soil
material, packed in a column into a leachant percolating through it. A continuous vertical up-flow is used,
which allows a column test under water-saturated conditions. The test conditions, including the flow rate of the
leachant, are chosen such that it can be concluded from the results, which components are rapidly being
washed out and which components are released under the influence of interaction with the matrix.
The test portion of the material with a specified particle size is packed in a column in a standardised manner.
Pre-equilibration is applied to reach local equilibrium at the start. The column size is related to the amount of
eluate needed for subsequent analysis and testing. The leachant is demineralised water with 0,001 M CaCl .
The leachant is percolated in up-flow through the column at a specified flow rate up to a fixed L/S ratio. The
eluate is collected in several separate fractions.
After the test, the leaching conditions, in terms of pH, electrical conductivity or DOC and, optionally, turbidity
or redox potential dictated by the material, shall be recorded.
NOTE These parameters often control the leaching behaviour of soil materials and are therefore important for
evaluation of the test results. Dissolved organic carbon (DOC), in particular, is crucial in soil and soil materials for many
inorganic and organic constituents.
The properties of the eluate are measured using methods developed for water analysis adapted to meet
criteria for analysis of eluates and/or the eluate may be subjected to subsequent ecotoxicological testing.
The results of the test are expressed as a function of liquid/solid ratio, in terms of both concentration (mg of
the constituents released per litre eluate) and release [mg of the constituents released cumulatively per kg of
material (dry mass)] of the constituents.
ISO/TS 21268-3:2007(E)
The procedure described in this part of ISO/TS 21268 is based on the more stringent test requirements for
determining the release of organic constituents and/or for subsequent ecotoxicological testing. If only the
release of inorganic constituents is to be measured, less stringent requirements may be adapted for some
steps of the procedure.
5 Reagents and materials
5.1 Demineralised water or deionised water or water of equivalent purity (5 < pH < 7,5) with a
conductivity < 0,5 mS/m in accordance with grade 3 specified in ISO 3696, made to 0,001 M CaCl .
5.2 Rinsing solutions: nitric acid (pro analyse) 0,1 mol/l and an organic solvent (acetone, pro analyse).
6 Apparatus
The materials and equipment specified in 6.2 to 6.13 shall be checked before use for proper operation and
absence of interfering substances, which can affect the result of the test.
The equipment specified under 6.5, 6.6, 6.13 and 6.14 shall also be calibrated.
6.1 Column made of glass or plastics with an internal diameter of 5 cm or 10 cm and a filling height of
about (30 ± 5) cm, fitted with filters (6.3) in the bottom and top sections made of appropriate materials
ensuring minimum interference with the contaminants of interest [e.g. polychlorotrifluoroethylene (PCTFE)]. In
the top and bottom of the column, a filter plate or a thin layer of fine-grained non-reactive material (e.g. fine
quartz sand) is applied to ensure proper water flow over the width of the column and as a support for the pre-
filter.
NOTE 1 A drawing of the column and accompanying equipment is given in Figure A.1.
NOTE 2 Glass of high quality is usually considered adequate for both metal and organic contaminants, particularly
since the pH range usually covered in soil testing does not reach the conditions (pH > 10 and pH < 3) where glass itself is
attacked. For ecotoxicity testing, eluates with both metal and organic contaminants are needed, which emphasises the
need to generate integrated eluates.
NOTE 3 When only organic constituents are analysed, stainless steel column and fittings can be applied.
6.2 Filters for in-line or off-line filtration of the eluates; they shall not adsorb the compounds of interest. This
shall be tested in preliminary experiments.
NOTE For organic compounds, glass-fibre filters without organic glue are suitable. If only inorganic contaminants are
analysed, alternative filter materials can be selected (e.g. cellulose acetate, PTFE).
6.3 Pre-filters for the column with a pore size of 1,5 µm to 20 µm. The filters shall be glass-fibre filters
without organic glue.
NOTE If only inorganic contaminants are analysed, alternative filter materials can be selected (e.g. cellulose acetate,
PTFE).
6.4 Peristaltic pump with an adjustable capacity of between 0 ml/h and 60 ml/h.
NOTE Additional pumps can be used.
6.5 Analytical balance with an accuracy of at least 0,1 g.
6.6 pH meter with an accuracy of at least ± 0,05 pH units.
6.7 Electrical conductivity meter with an accuracy of at least 0,1 mS/m.
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ISO/TS 21268-3:2007(E)
6.8 Tubing material (made of ethylene-tetrafluoroethylene, ETFE) adapted to the analysis to be performed
(see ISO 5667-3).
NOTE When only organic constituents are analysed, stainless steel tubing can be used. When only inorganic
constituents are analysed, polytetrafluoroethylene (PTFE) or similar tubing materials can be used.
6.9 High-quality glass bottles with an appropriate volume, and with a screw cap with a PTFE inlay, for
eluate collection and preservation of eluate samples (in accordance with ISO 5667-3).
NOTE If only inorganic contaminants are analysed, alternative bottle materials can be selected (e.g. HDPE, PTFE).
6.10 Crushing equipment: a jaw crusher or a cutting device.
6.11 Sieving equipment with sieves of 4 mm nominal screen size.
6.12 Sample splitter for sub-sampling of laboratory samples (optional).
6.13 Redox potential meter (optional).
6.14 Turbidity meter as specified in ISO 7027.
6.15 Centrifuge operating at 20 000g to 30 000g using centrifuge tubes of fluorinated ethylene propylene
(FEP) or tubes of an alternative material, which is inert with regard to both inorganic and organic compounds
and suitable for high-speed centrifugation.
Alternatively, if a high-speed centrifuge is not available, a centrifuge operating at 2 000g to 2 500g using glass
bottles may be used in combination with increased centrifugation time. Cooling shall be applied to maintain
the desired temperature.
7 Sample pre-treatment
7.1 Sample preparation
Obtain a laboratory sample of at least 10 kg, in case a wide column (10 cm) is used. Use a sample splitter
(6.12) or apply coning and quartering to split the sample.
The laboratory sample shall be stored in closed packages and at low temperatures (4 °C), in order to prevent
unwanted changes in the material (see ISO 18512).
Sampling should be performed in accordance with the guide to the preparation of a sampling plan for soil
materials, as specified in ISO 10381-1 to ISO 10381-6, in order to obtain representative laboratory samples.
NOTE 1 Depending on the maximum particle size, the splitting can require reduction of the coarser particles to comply
with the rules of sampling.
NOTE 2 The size of the laboratory sample is dependent on the particle size distribution of the soil to be analysed
(ISO 10381-1 to ISO 10381-6). The prescribed sample size will generally be adequate.
NOTE 3 If a 10 kg laboratory sample is not available, the test may be carried out with less material.
NOTE 4 If needed for chemical analysis or ecotoxicological testing, larger volumes of eluate can be obtained by
combining eluates from replicate tests after centrifugation (or filtration).
NOTE 5 Alternatively, larger volumes of eluate may also be produced in a single test using a larger column, provided
that the proportions in terms of L/S are maintained.
Any deviation(s) to accommodate sample size or volume requirements shall be recorded in the test report.
ISO/TS 21268-3:2007(E)
7.2 Particle size reduction
The test shall be carried out preferably on material as received. However, the test portion to be prepared shall
have a grain size of less than or equal to 4 mm at least 95 % (mass fraction). Oversized material in the
sample shall be separated by sieving over a 4 mm sieve. The mass and the nature of the oversized material
shall be recorded. If oversized material is not of natural origin or exceeds 5 % (mass fraction), the entire
oversized fraction shall be crushed with suitable crushing equipment. On no account shall the material be
finely ground. Irrespective of any necessary size reduction, the separate fractions, with the exception of the
non-crushable material, shall be mixed to constitute the test sample. If the laboratory sample cannot be
crushed or sieved because of its water content, it is allowed, only in this case, to dry the laboratory sample.
The drying temperature shall not exceed 25 °C. For the processing of soil samples, refer to ISO 10381-6.
NOTE 1 Due to sieving, contamination of the sample can occur to an extent which affects the leaching of some
constituents of concern, e.g. chromium, nickel and molybdenum form stainless steel equipment or plasticisers from plastic
sieves.
NOTE 2 Sieving and drying at 25 °C can lead to a loss of semi-volatile components (inorganic and organic). In this
case, particle size reduction and drying is best avoided.
7.3 Test portion
Take, from the test sample, a test portion with a volume of approximately 0,6 l, if the column has a diameter of
5 cm, and of 2,4 l, if the column has a diameter of 10 cm. Use a sample splitter (6.12) or apply coning and
quartering to split the test sample.
7.4 Determination of dry matter content
The dry matter content of the sample shall be known and taken into account when calculating the L/S ratio.
Determine the dry matter content (w ) on a separate test portion. The dry mass shall be determined at
dm
(105 ± 5) °C in accordance with ISO 11465. The dry matter content is calculated in Equation (1):
wm=×100 m (1)
dm D W
where
w is the dry matter content (%);
dm
m is the mass of the dried sample (kg);
D
m is the mass of the undried sample (kg).
W
If, for reasons expressed in 7.2 or 7.3, the material was (partly) dried before particle size reduction and/or
sample splitting, the overall mass loss shall be taken into account.
8 Procedure
8.1 Temperature
The percolation test shall be carried out at a temperature of (20 ± 5) °C.
NOTE A constant temperature of 20 °C in the test can be achieved by either controlling the temperature of the
laboratory, or controlling the temperature of the leachant and insulating the column and accompanying equipment.
For material that is very sensitive to biological degradation, performance of the test at reduced temperature
(e.g. 4 °C) and preventing direct exposure to light will limit biological activity significantly. If the test is modified
in this way, this deviation shall be reported in the test report.
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ISO/TS 21268-3:2007(E)
8.2 Preparation
Rinse the column with top and bottom sections (6.1), filters (6.2) and bottles (6.9) with nitric acid and/or an
organic solvent (5.2) and water (5.1) respectively. Weigh the dry column, including the top and bottom
sections, filters and filter plates or layers of fine-grained material, to an accuracy of 1 g.
NOTE Alternatively, a heat treatment can be applied to clean temperature-resistant equipment of sorbed organic
contaminants.
8.3 Packing of the column
Fit the bottom section, equipped with a filter plate or a layer of fine-grained chemically inert material (e.g. fine
quartz sand) of approximately 1 cm and a pre-filter (6.3) to the column. Fill the column with the test portion, up
to a bed height of (30 ± 5) cm in at least five consecutive layers.
⎯ Introduce each layer into the column in three sub-layers and level each sub-layer separately.
⎯ Pack each layer, using as a rammer a weight of 125 g in the case of a column with a diameter of 5 cm,
and of 500 g in the case of a column with a diameter of 10 cm. Drop the weight three times onto each
layer, letting it fall down 20 cm along a rod used as a guide. Fix this rod to the centre of a disk, which is
placed on the layer to be packed. Cover the whole surface of the column with the disk (as is shown in
Figure A.1).
⎯ For the last layer, check the remaining height and adjust the necessary mass in order to get (30 ± 5) cm.
NOTE 1 In order to determine the proper mass for each layer, a preliminary test may be carried out. In that case, put a
7 cm to 8 cm layer in the column, pack it and calculate the mass necessary to obtain a layer of approximately 6 cm.
NOTE 2 If the column is not high enough to work according to the above-mentioned packing procedure, a heightening
device may be required.
NOTE 3 It is difficult to pack some specific materials in the column in an appropriate way. Annex B gives guidelines on
how to handle that specific case.
Fit the top section of the column, equipped with a filter plate and a pre-filter (6.3), to prevent entrainment of
fine particles with the eluate. The top section and pre-filter shall be fitted such that the liquid flow cannot
bypass the filter, and such that no open space (dead volume) is left above the material.
Care should be taken in positioning the pre-filter in place; the filter may tear.
Weigh the column thus filled to an accuracy of 1 g. Determine the dry mass (m ), in kilograms, of the test
D
portion in the column, in accordance with Equation (2):
mm=⋅w 100 (2)
DW dm
where
m is the mass of the (moist) test portion in the column (kg).
W
w is the dry matter content (%);
dm
Fit the outlet-hose to the top section of the column and to the in-line filter (6.2), when an in-line filter is used.
ISO/TS 21268-3:2007(E)
8.4 Start of the test
Saturate the column with water (5.1) either by using the pump (6.4) or by hydrostatic pressure.
NOTE 1 See Annex A for a description of the methods of saturation.
Stop the pump, or take away the hydrostatic pressure, when the material in the column is completely
saturated, but the outlet hose remains empty. Leave the saturated material for a period of at least two days, in
order to equilibrate the system.
NOTE 2 To facilitate equilibration and the procedure of checking the equilibrium conditions, recirculation of the eluate
may be applied (see Annex A).
After the equilibration period, start the pump (again) and set the flow rate such that the linear velocity is
approximately (15 ± 2) cm/day through the empty column.
Calculate the flow rate in accordance with Equation (3):
qv=×π×d× 0,010 4 (3)
L
where
q is the leachant flow rate (ml/h);
v is the linear velocity of the leachant through the empty column (cm/day);
L
d is the diameter of the column (cm).
NOTE 3 A linear velocity of 15 cm/day corresponds to a flow rate of 12 ml/h for a column with a diameter of 5 cm, and
for a column with a diameter of 10 cm it is equivalent to a flow rate of 48 ml/h.
Connect the outlet hose (6.8) to an eluate collection bottle of appropriate size (6.9). Start the pump and
change the collection bottle after a quantity of (0,1 ± 0,02) × the mass of the test portion (m ) of leachant has
W
passed through.
Transfer the supernatant to centrifuge tubes (6.15).
There are two options for solid-liquid separation.
1) Centrifuge the eluate for 30 min at 20 000g to 30 000g using a high-speed centrifuge (6.15).
2) Centrifuge the eluate for 5 h at 2 000g to 2 500g in glass bottles using a lower-speed centrifuge
(6.15).
Cooling shall be applied to maintain the temperature at (20 ± 5) °C (see 8.1).
NOTE 4 Based on Stoke's law, the results of both centrifugation methods are expected to be comparable.
Gentle breaking shall be applied in order to avoid resuspension. The deceleration time shall not exceed
20 min.
Filter the eluate fraction off-line over a 0,45 µm membrane filter (6.2), if no in-line filter was used.
Measure the pH, electrical conductivity and DOC of this eluate portion. Measurement of the turbidity and
redox potential are highly recommended.
When an in-line filter is used, this filter shall be regularly checked concerning clogging due to the small filter
diameter. If clogging occurs, the filter shall be replaced.
8 © ISO 2007 – All rights reserved

ISO/TS 21268-3:2007(E)
A water lock will be needed on the lid, to avoid back-pressure in the column when the bottle with lid is gas
tight.
Keeping the collection bottles under inert atmosphere may be necessary when investigating reducing soil
materials, to prevent the occurrence of oxidation reactions.
If only inorganic constituents are measured, the eluate can be filtered using the appropriate membrane filters
(6.2) and a vacuum or pressure filtration device (6.3). When filtration as specified is not possible in less than
1 h with a liquid flow rate of at least 30 ml/cm /h, a liquid-solid separation procedure, specific for the
considered case, shall be applied. Report the details in the test report. This specific procedure shall not
include the use of additives.
NOTE 5 For inorganic constituents, it is often preferable to pre-centrifuge the eluate at 2 000g to 3 000g for 20 min
using glass bottles with a screw cap and polytetrafluoroethylene inlay (or, if possible, using the leaching bottle directly)
prior to filtration.
Under certain circumstances, particularly for alkaline eluates, it is recommended to measure the pH and redox
potential of the raw eluate prior to filtration or centrifugation, since these operations may change the pH and
redox of the eluate.
Analysis of DOC in the eluate is highly recommended, as this property is relevant both for the release of
metals as well as for organic substances.
8.5 Collection of additional eluate fractions
Check the flow rate of the leachant and possible clogging of the in-line filter (if used) as often as needed, but
at least three times per week, and adjust to the original linear velocity, in the range of (15 ± 2) cm/day. If
clogging occurs, the filter shall be replaced.
Replace the collection bottle with a new one as soon as a quantity of water (5.1) in accordance with Table 1
has passed through. These are fractions 2 to 7. Take care that both criteria (concerning the volume of the
actual eluate fraction as well as the cumulative L/S ratio) shall be fulfilled.
Centrifuge or filter each eluate fraction off-line as specified in 8.4. Measure the pH, electrical conductivity, and
DOC of each eluate portion. Measurement of the redox potential and turbidity are highly recommended.
At each eluate collection moment, measure the time and volume of the eluate fraction and calculate the L/S-
ratio and the average linear velocity of the leachant over the collection period of that fraction. Also measure
the actual linear velocity. Report all these values.
Table 1 — Table for collection of eluate fractions
Fraction number Fraction volume (l) Cumulative L/S ratio (l/kg)
a
(= L/S ratio times dry mass)
(0,1 ± 0,02) × m 0,1 ± 0,02
D
2 (0,1 ± 0,02) × m 0,2 ± 0,04
D
3 (0,3 ± 0,05) × m 0,5 ± 0,08
D
(0,5 ± 0,01) × m 1,0 ± 0,15
D
5 (1,0 ± 0,2) × m 2,0 ± 0,3
D
6 (3,0 ± 0,2) × m 5,0 ± 0,4
D
(5,0 ± 0,2) × m 10,0 ± 0,1
D
a
In the case of high salt loads (electrical conductivity > 7 500 mS/m), the density of the eluate in
the first few fractions is significantly more than 1 g/ml. In that case, the volume of these fractions of
eluate shall be measured and used for the calculations instead of the mass.
ISO/TS 21268-3:2007(E)
The test itself is finished when the L/S ratio of 10 l/kg dry matter is reached.
NOTE 1 For specific scenarios (for instance a landfill with top cover), it can be sufficient to know the leaching
characteristics up to a pre-determined L/S ratio, for instance L/S = 2. In that case, the test can be stopped after the
collection of the fifth eluate fraction.
NOTE 2 For ecotoxicological testing, the fractions 1 to 5 (or parts of these fractions) can be combined for receiving a
cumulative L/S ratio of 2. If large amounts of leachate are needed for testing, a cumulative L/S ratio of 10 may be used.
NOTE 3 When no automated eluate collection apparatus is available, a collection scheme can be composed within the
ranges that are allowed in the flow rate (15 ± 2) cm/d, and in fraction volume (see Table 1), that enables eluate collection
within working hours.
NOTE 4 The execution time of the test can be calculated from Equation (4):
tm=×L S ×1000 24×q (4)
()()
D
where
t is the execution time of the test, expressed in days (d);
L/S is the final liquid to solid ratio, expressed in litres per kilogram of dry matter (l/kg dry matter);
m is the dry mass of the test portion, expressed in kilograms (kg);
D
q is the leachant flow rate, expressed in millilitres per hour (ml/h).
8.6 Furt
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