SIST-TS CEN/TS 14997:2007
(Main)Characterization of waste - Leaching behaviour tests - Influence of pH on leaching with continuous pH-control
Characterization of waste - Leaching behaviour tests - Influence of pH on leaching with continuous pH-control
This document specifies a test method for the determination of the influence of pH on the leachability of inorganic constituents from a waste material. Equilibrium condition as defined in the document is established by continuous adjustment of the pH by addition of acid or base to reach desired pH values. This test method produces eluates, which are subsequently characterized physically and chemically.
This document is a parameter specific test as specified in EN 12920. The application of this test method alone is not sufficient for the determination of the detailed leaching behaviour of a waste under specified conditions.
NOTE This generally requires the application of several test methods, behavioural modelling and model validation as specified in EN 12920.
Charakterisierung von Abfällen - Untersuchung des Auslaugungsverhaltens - Einfluss des pH-Wertes auf die Auslaugung bei kontinuierlicher pH-Wert-Kontrolle
Dieses Dokument legt ein Prüfverfahren zur Bestimmung des Einflusses des pH Wertes auf die Auslaug¬barkeit von anorganischen Bestandteilen aus einem Abfall fest. Der Gleichgewichts¬zustand, wie er in diesem Dokument definiert ist, wird durch kontinuierliche Einstellung des pH-Wertes durch Zugabe von Säure oder Base hergestellt, um die gewünschten endgültigen pH Werte zu er¬reichen. Dieses Prüfverfahren führt zu Eluaten, die anschließend physikalisch und chemisch charakterisiert werden.
Dieses Dokument beinhaltet eine parameterspezifische Prüfung, wie in EN 12920 festgelegt. Die Anwen¬dung nur dieses Prüfverfahrens ist für die Bestimmung des genauen Auslaugungsverhaltens eines Abfalls unter festgelegten Bedingungen nicht ausreichend.
ANMERKUNG Das erfordert im Allgemeinen die Anwendung mehrerer Prüfverfahren, die Verhaltensmodellierung und Validierung von Modellen, wie in EN 12920 festgelegt.
Caractérisation des déchets - Essais de comportement a la lixiviation - Influence du pH sur la lixiviation avec contrôle continu du pH
Le présent document s’applique a la détermination de l’influence du pH sur la lixiviabilité des constituants inorganiques provenant de déchets. L’état d’équilibre tel que défini dans le document s’obtient par un ajustement permanent du pH en ajoutant un acide ou une base pour atteindre les valeurs de pH souhaitées. Cette méthode d’essai produit des éluats qui sont ensuite caractérisés du point de vue physico-chimique.
Le présent document est un essai paramétrique, tel que spécifié dans l’EN 12920. Cette méthode d’essai n’est pas suffisante, a elle seule, pour la détermination en détail du comportement a la lixiviation d’un déchet dans des conditions spécifiées.
NOTE En regle générale, ceci nécessite l’application de plusieurs méthodes d’essai, une modélisation du comportement, ainsi qu’une validation des modeles, comme spécifié dans l’EN 12920.
Karakterizacija odpadkov - Izluževalni preskusi - Vpliv pH na izluževanje z uravnavanjem pH
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST-TS CEN/TS 14997:2007
01-april-2007
Karakterizacija odpadkov - Izluževalni preskusi - Vpliv pH na izluževanje z
uravnavanjem pH
Characterization of waste - Leaching behaviour tests - Influence of pH on leaching with
continuous pH-control
Charakterisierung von Abfällen - Untersuchung des Auslaugungsverhaltens - Einfluss
des pH-Wertes auf die Auslaugung bei kontinuierlicher pH-Wert-Kontrolle
Caractérisation des déchets - Essais de comportement a la lixiviation - Influence du pH
sur la lixiviation avec contrôle continu du pH
Ta slovenski standard je istoveten z: CEN/TS 14997:2006
ICS:
13.030.01 Odpadki na splošno Wastes in general
SIST-TS CEN/TS 14997:2007 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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TECHNICAL SPECIFICATION
CEN/TS 14997
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
November 2006
ICS 13.030.01
English Version
Characterization of waste - Leaching behaviour tests - Influence
of pH on leaching with continuous pH-control
Caractérisation des déchets - Essais de comportement à la Charakterisierung von Abfällen - Untersuchung des
lixiviation - Influence du pH sur la lixiviation avec contrôle Auslaugungsverhaltens - Einfluss des pH-Wertes auf die
continu du pH Auslaugung bei kontinuierlicher pH-Wert-Kontrolle
This Technical Specification (CEN/TS) was approved by CEN on 9 October 2006 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.
CEN members are the national standards bodies of Austria, Belgium, 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 United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 14997:2006: E
worldwide for CEN national Members.
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CEN/TS 14997:2006 (E)
Contents Page
Foreword.3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms and definitions .5
4 Symbols and abbreviations .6
5 Principle.7
6 Reagents and laboratory devices .7
6.1 Reagents.7
6.2 Laboratory devices.7
7 Sampling.8
7.1 Laboratory sample.8
7.2 Test sample .8
7.3 Determination of dry residue of the sample .9
7.4 Test portion .9
8 Test procedure.9
8.1 Contact time .9
8.2 pH range .10
8.3 Leaching test.10
8.4 Natural pH.13
9 Eluate treatment, storage and analysis.13
10 Blank tests.13
11 Performance characteristics .14
12 Test report .14
Annex A (informative) Example of a data sheet .16
Annex B (informative) Operation and uses of the test: influence of pH on the leaching behaviour .17
Annex C (informative) Preliminary determination of the acid/base consumption.22
Annex D (informative) Examples of acid and base neutralisation capacities for waste, soil,
sediment and construction materials.26
Bibliography .29
2
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CEN/TS 14997:2006 (E)
Foreword
This document (CEN/TS 14997:2006) has been prepared by Technical Committee CEN/TC 292
“Characterization of waste”, the secretariat of which is held by NEN.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
For relationship with EU Directive(s), see informative Annex ZA, B, C or D, which is an integral part of this
document.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this CEN Technical Specification: Austria, Belgium, 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 United Kingdom.
3
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CEN/TS 14997:2006 (E)
Introduction
This document has been developed primarily to support the requirements for leaching behaviour testing within
EU and EFTA countries. Tests to characterize the behaviour of waste materials can generally be divided into
three categories. The relationship between these tests is summarized below:
a) “Basic characterization“ tests are used to obtain information on the short and long term leaching behaviour
and characteristic properties of waste materials. Liquid/solid (L/S) ratios, leachant composition, factors
controlling leachability such as pH, redox potential, complexing capacity, ageing of waste and physical
parameters are addressed in these tests.
b) “Compliance“ tests are used to determine whether the waste complies with a specific behaviour or with
specific reference values. The tests focus on key variables and leaching behaviour previously identified by
basic characterization tests.
c) “On-site verification“ tests are used as a rapid check to confirm that the waste 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 specified in this document belongs to category (a): basic characterization tests.
In the test described in this standard an equilibrium condition is established as a result of continuous
adjustment of pH. Size reduction is performed to accelerate reaching of equilibrium condition.
This test is different from the "Influence of pH on leaching with initial acid/base addition " (see CEN/TS 14429)
in which the pH is controlled by addition of pre-determined amounts of acid or base to reach desired end pH
values. The test is aiming at approaching equilibrium at the end of the procedure.
NOTE In Annex B specific uses of both the pH dependence test with initial acid/ base addition and the pH
dependence test with continuous pH control are indicated.
4
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CEN/TS 14997:2006 (E)
1 Scope
This document specifies a test method for the determination of the influence of pH on the leachability of
inorganic constituents from a waste material. Equilibrium condition as defined in the document is established
by continuous adjustment of the pH by addition of acid or base to reach desired pH values. This test method
produces eluates, which are subsequently characterized physically and chemically.
This document is a parameter specific test as specified in EN 12920. The application of this test method alone
is not sufficient for the determination of the detailed leaching behaviour of a waste under specified conditions.
NOTE This generally requires the application of several test methods, behavioural modelling and model validation as
specified in EN 12920.
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.
EN 12506, Characterization of waste – Analysis of eluates - Determination of pH, As, Ba, Cd, Cl, Co, Cr, Cr VI,
- 2-
Cu, Mo, Ni, NO , Pb, total S, SO , V and Zn
2 4
EN 13370, Characterization of waste – Analysis of eluates – Determination of Ammonium-N, AOX,
- -
conductivity, Hg, phenol index, TOC, CN , F
easily liberable
EN 14346, Characterization of waste – Calculation of dry matter by determination of dry residue or water
content
EN 14899, Characterisation of waste – Sampling of waste materials – Framework for the preparation and
application of a Sampling Plan
EN 15002, Characterization of waste – Preparation of test portions from the laboratory sample
EN ISO 5667-3, Water quality – Sampling – Part 3: Guidance on the preservation and handling of water
samples (ISO 5667-3:2003)
EN ISO 3696:1995 Water for analytical laboratory use – Specification and test methods (ISO 3696:1987)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
dry residue of the sample
w
dr
o
remaining mass fraction of a sample after a drying process at 105 C
[EN 14346]
3.2
eluate
solution obtained by a laboratory leaching test
5
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CEN/TS 14997:2006 (E)
3.3
equilibrium condition
condition achieved when the acid or base consumption during a checking period at the last 4 h of the test is
less than 2 % of the total acid or base consumption during the entire test
3.4
laboratory sample
sample or subsample(s) sent to or received by the laboratory
[IUPAC, 1997] [15]
3.5
liquid to solid-ratio
L/S
ratio between the amount of liquid (L) and of solid (S) in the test
NOTE L/S is expressed in l/kg dry matter.
3.6
leachant
liquid to be mixed with the test portion in the leaching procedure
3.7
suspension
mixture of leachant and test portion
3.8
test portion
amount or volume of the test sample taken for analysis, usually of known weight or volume
[IUPAC, 1997]
3.9
test sample
sample, prepared from the laboratory sample, from which test portions are removed for testing or for analysis
[IUPAC, 1997]
4 Symbols and abbreviations
ANC acid neutralization capacity
BNC base neutralization capacity
DOC dissolved organic carbon
L/S liquid to solid ratio
M dried mass of the test portion
d
m mass after drying
d
M un-dried mass of the test portion
w
m mass before drying
r
t time at the start of the leaching test
0
6
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CEN/TS 14997:2006 (E)
V volume of acid or base used in leachant
A/B
V volume of demineralised water used in leachant
demin
w dry residue of the sample
dr
5 Principle
Separate test portions are leached at a fixed L/S ratio with leachants where the pH is adjusted and controlled
at pre-set pH-values. At least 8 final pH values are required, covering at the minimum the range pH 4 - pH 12
(both included i.e. the lowest value ≤4 and the highest value ≥12). The amounts of acid or base needed to
cover the pH range can be derived from the results of a preliminary titration, from available experimental data
on the material to be tested or from an arbitrary division of the predetermined maximum consumption of acid
and base. The tests are carried out at a fixed contact time at the end of which equilibrium condition can be
assumed to be reached for most constituents in most waste materials to be characterized. The equilibrium
condition as defined in the standard is verified at the end of the leaching procedure.
The results are expressed in mg/l of constituents for each final pH value. For each final pH value also the
+
quantity of acid that is added is expressed in mol H /kg dry matter and the quantity of base that is added is
- +
expressed as mol OH /kg dry matter (-mol H /kg dry matter).
NOTE 1 Other expression of results is possible (including mg leached /kg dry matter). Since this test is aiming at
equilibrium condition i.e. solubility controlled, the results alone cannot be used to quantify the soluble mass fraction.
The ANC or BNC of the waste is also determined. The ANC or BNC is defined as the amount of acid or base
+
(+/- mol H /kg dry matter) needed to reach a given user-defined end-pH. It is graphically [2] or numerically
derived from a curve representing each end-pH obtained as a function of the amounts of acid or base added
NOTE 2 The pH range covered by the test may be restricted to a pH range relevant for the specific material and the
considered problem (see 8.2).
6 Reagents and laboratory devices
6.1 Reagents
6.1.1 Distilled water, demineralised water or water of equivalent purity with a conductivity < 0,1 mS/m
[ISO 3696].
6.1.2 Nitric acid (pro analysis), 0,1 mol/l to 5 mol/l.
6.1.3 Sodium hydroxide, NaOH, 0,1 mol/l to 5 mol/l.
NOTE NaOH is unstable due to possible uptake of CO . Therefore it is recommended to prepare a fresh solution.
2
6.2 Laboratory devices
6.2.1 Analytical balance (accurate to 0,1 g).
6.2.2 Bottles or vessels equipped with a lid.
Use bottles or vessels (250 ml for the test portions of 15 g of dry mass, 500 ml for test portions of 30 g dry
mass and 1 l for test portions of 60 g dry mass) made of polypropylene (PP), polyethylene (PE) or PTFE. In
the bottles or the lid of the vessels an opening must be present for the pH-electrodes and for input of acid
and/or base and a small outlet for gas. The bottles have to be as close as possible to prevent CO uptake.
2
NOTE At high pH values it is recommended to perform the test under nitrogen to prevent CO intake .
2
7
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CEN/TS 14997:2006 (E)
6.2.3 Crushing equipment, e.g. a jaw crusher.
NOTE Crushing is prescribed in 7 to avoid unnecessary grinding to very fine particle sizes, such as takes place in a
rotary swing mill, ball mill or similar device.
6.2.4 Stirring device.
The parts in contact with sample and eluate shall be made of materials not affecting the outcome of the test
like glass, PTFE.
6.2.5 Membrane filters for the filtration device.
Use filters or a filter device, fabricated from inert material, which is compatible with the waste and has a pore
size of 0,45 µm. Filter must be pre-washed with demineralized water or similarly clean in order to remove
DOC.
6.2.6 pH meter.
Use a pH meter with a measurement accuracy of at least ± 0,05 pH units.
NOTE At high pH values the use of specific electrodes is recommended.
6.2.7 Sample splitters for a minimum test portion size equivalent of 15 g of dry mass.
6.2.8 Sieving equipment with sieve of 1 mm nominal screen sizes.
NOTE Due to crushing and sieving, contamination of the sample may occur to an extent, which may affect the
leached amounts of some constituents of concern, e.g. Co and W from tungsten carbide crushing equipment or Cr, Ni, Mo
and V from stainless steel equipment.
6.2.9 Device for continuous pH control with a precision of 0,2 pH units through acid/base addition.
NOTE The pH-control of the suspension is achieved by continuous addition of acid/base by measuring the pH of the
solution in case of a deviation from the desired pH a continuous dosing of acid or base is required.
6.2.10 Vacuum filtration device or pressure filtration device.
7 Sampling
7.1 Laboratory sample
Perform sampling in accordance with EN 14899 in order to obtain a representative laboratory sample.
The laboratory sample shall consist of a mass equivalent of at least 1 kg of dry mass.
7.2 Test sample
The tests shall be made on material with a grain size of 95 % less than 1 mm. In order to ensure that the test
sample consists in 95 % mass of particles less than 1 mm in diameter, it shall be sieved, using the sieving
equipment, to separate the oversized particles. If oversized material exceeds 5 % (mass) the entire oversized
fraction shall be crushed. Any non-crushable material (e.g. metallic parts such as nuts, bolts, scrap) shall be
separated from the oversized fraction and the weight and nature of the non-crushable material shall be
recorded. Crushed and uncrushed material shall be mixed to constitute the test sample.
Moist material that is not possible to sieve needs to be dried prior to sieving and/or crushing. The drying
o
temperature shall not exceed 40 C.
8
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CEN/TS 14997:2006 (E)
NOTE 1 The crushed material can change upon storage due to ageing of fresh surfaces. It is therefore recommended
to test the material as soon as possible after crushing.
NOTE 2 It is recommended that materials with a high natural pH should be crushed under nitrogen in order to avoid
contact with air leading to carbonation.
7.3 Determination of dry residue of the sample
The whole test sample, complying with the size criteria in 7.2 shall not be further dried. The dry residue (w )
dr
of the test sample shall be determined on a separate test portion.
o o
The dry residue of the sample shall be determined at 105 C ± 5 C according to EN 14346. The dry residue
expressed as a percentage of the mass fraction is calculated as follows:
m
d
(1)
w = 100 ×
dr
m
r
where
w is the dry residue of the sample expressed as percentage (%);
dr
m is the mass after drying expressed in grams (g);
d
m is the mass before drying expressed in grams (g).
r
7.4 Test portion
Prepare at least 8 test portions by the use of a sample splitter or by coning and quartering in accordance with
EN 15002. Based on sample heterogeneity and eluate volume requirement for analysis, test portion size shall
be either M = 15 g, 30 g or 60 g (with a tolerance of ± 10 %).
d
Calculate the undried mass of the test portion M in grams to be used for the test in accordance with
w
Equation 2:
M
d
M = ×100 (2)
w
w
dr
where
M is the total mass of the test portion expressed in grams (g);
w
M is the dry mass of the test portion expressed in grams (g).
d
8 Test procedure
8.1 Contact time
The leaching procedure consists of two defined stages:
— Period A (equilibration period) from t up to t + 44 h for equilibration at continuously controlled pH;
0 0
— Period B (verification period) from t up to t + 48 h for verification of equilibrium condition at
0+44 h 0
continuously controlled pH.
The amount of acid or base added is recorded after each of these periods.
9
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CEN/TS 14997:2006 (E)
The pH in the liquid is recorded after each of these periods.
The total contact period (A+B) is 48 h.
8.2 pH range
The test shall cover the range pH 4 to pH 12 (both included i.e. the lowest value ≤ 4 and the highest value
≥ 12) with at least 8 pH values tested including the natural pH (without acid or base addition). The maximum
difference between two consecutive pH values shall not exceed 1,5 pH units.
NOTE The pH range covered by the test may be restricted to a pH range relevant for the specific material and the
considered problem. The pH range to be covered may depend on the specific properties of the waste material, the
available information on this material and the questions to be answered by performing the test. The number of pH levels
considered can be reduced, correspondingly.
8.3 Leaching test
8.3.1 General
The following procedure applies for each of the chosen pH values to be tested. Testing at natural pH is
described in 8.4.
8.3.2 Preparation of leachant
+
Identify the acid or base consumption for reaching the relevant pH values as A (mol H /kg dry matter) or B
-
(mol OH /kg dry matter).
NOTE 1 The acid or base consumption for the considered pH values may be derived from available information, from
the preliminary procedures in Annex C or from information in Annex D.
The volume (V) of liquid consists of the water content of the test sample and the amount of leachant (V ).
L
Calculate the volume (V) of liquid to establish L/S = (10 ± 0.2) l/kg for the actual size of test portion M (see
w
7.4) including the volume of acid or base in accordance with Equation 3.
V = 10 × M (3)
d
where
V is the total volume of liquid in the test expressed in millilitres (ml);
M is the dry mass of the test portion expressed in grams (g) (see 7.4).
d
NOTE 2 In relation to L/S -ratio, V in this equation is equivalent with the ”L” and M is equivalent to the “S”.
d
Calculate the amount of leachant (V ) to be added to the actual size of test portion and compensate for the
L
moisture content in the test portion, in accordance with Equation 4:
100
V = V − ( − 1) × M (4)
L d
w
dr
where
V is the volume of added leachant expressed in millilitres (ml).
L
V is the total volume of liquid in the test expressed in millilitres (ml);
w is the dry residue of the waste expressed as percentage of total weight (%) (see 7.3);
dr
10
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CEN/TS 14997:2006 (E)
M is the dry mass of the test portion expressed in grams (g) (see 7.4).
d
The volume of acid or base added shall not exceed a volume corresponding to M 1 (V ). This volume is
d L/S 1
calculated in accordance with Equation 5:
V = 1× M (5)
L / S1 d
where
V is the volume of liquid corresponding to L/S 1 in the test expressed in millilitres(ml);
L/S 1
M is the dry mass of the test portion expressed in grams (g) (see 7.4)
d
Calculate the minimum concentration of acid (C ) or base (C ) to be used as follows, with Equation 6 or 7.
A B
A ×M
d
C = (6)
A
V
A
or
− B ×M
d
C = (7)
B
V
B
where
V is the volume of acid needed expressed in millilitres (ml);
A
V is the volume of base needed expressed in millilitres (ml);
B
+
A is the acid consumption for the pH (mol H /kg dry matter);
+
B is the base consumption for the pH (mol OH/kg dry matter, expressed as –mol H /kg dry matter);
C is the minimum concentration of the acid expressed in mole per litre (mol/l) (see 6.1.2);
A
C is the minimum concentration of the base expressed in mole per litre (mol/l) (see 6.1.4).
B
NOTE 3 The concentration of the acid or base can be estimated from a preliminary titration (Annex C) or previous
results from similar materials (Annex D)
Chose a convenient concentration of the acid (c ) or base (c ), which is stronger than the calculated minimum
A B
concentration.
Calculate the volume V of demineralised water (see 6.1.1) to be added initially to the test portion as
demin
follows:
A × M
d
V = V − (8)
demin L
c
A
or
− B × M
d
V = V − (9)
demin L
c
B
where
11
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CEN/TS 14997:2006 (E)
V is the volume of demineralised water used expressed in millilitres (ml);
demin
V is the volume of prepared leachant expressed in millilitres (ml);
L
+
A is the acid consumption for the pH (mol H /kg dry matter);
- +
B is the base consumption for the pH (mol OH /kg dry matter, expressed as –mol H /kg dry matter);
c is the chosen concentration of the acid expressed in mole per litre (mol/l) (see 6.1.2);
A
c is the chosen concentration of the base expressed in mole per litre (mol/l) (see 6.1.4);
B
M is the dry mass of the test portion expressed in grams (g) (see 7.4).
d
Prepare the pH control device (see 6.2.9) with the chosen concentration of acid or base.
8.3.3 Leaching procedure
Carry out the test at a temperature of 20 °C ± 5 °C.
Select the appropriate bottle size according to the test portion size. For M =15 g, 30 g and 60 g, this means
d
respectively bottle sizes of 250 ml, 500 ml and 1000 ml.
Clean the bottle before use by filling it with 1 mol/l nitric acid (see 6.1.3), leaving it for at least 24 h and then
flushing it out with demineralised water (see 6.1.1).
Place one of the test portions in the rinsed bottle.
Add the volume of demineralised water V .
demin
Connect the bottle to the pH control device (6.2.9) and insert the pH electrode.
The suspension is stirred for 15 min ± 5 min before acid or base addition and the starting pH is recorded.
To ensure proper suspension of waste particles mixing of the solution is applied throughout the procedure.
Start pH control at the preset pH value with a tolerance of ± 0,2 pH unit at t and continue until t = t +48h.
0 0
Measure and record the pH at t .
0+4h
NOTE 1 The pH measurement may be done over a 5 min interval to avoid incidental deviation due measurement
shortly after acid or base addition. If the added acid or base disturbs the pH-measurements the acid or base
addition can be stopped during the measurement of the pH.
The pH at t shall not deviate more than 0,3 pH unit from the preset pH value. If this requirement is not met,
0+4h
this leaching procedure shall be aborted and restarted with another acid or base strength.
Measure and record the acid or base consumption and the pH at t and t .
0+44h 0+48h
The pH value measured before filtration at t will be the one associated to the analysis of the eluate.
0+48h
NOTE 2 pH is measured directly in the bottle at t since filtration may change pH in the eluate.
0+48h
The test aims at a final L/S ratio of 10 after acid or base addition. The ultimate L/S shall not deviate more than
10 % from L/S = 10 l/kg. If the L/S exceeds 11 because of high acid or base consumption of the material at
the specific pH value, this condition shall be repeated using a stronger acid or base for pH adjustment.
12
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CEN/TS 14997:2006 (E)
NOTE 3 For some waste materials gas formation may occur (e.g. CO , H , etc.). Pay attention when opening the
2 2
bottles to release the pressure (preferably in a fume hood).
Report and check the acid or base consumption up to t and between t and t .
0+44h 0+44h 0+48 h
Report the pH deviation at t , t and t from the preset value. The acid or base addition between t
0+4h 0+44h 0+48h 0+44h
and t shall not exceed 2 % of the total acid or base consumption (mol/kg) between t and t . This is the
0+48h 0 0+48h
limit for achieving equilibrium condition (see 3.3). A special note shall be made in the report if this requirement
is not met.
Allow the suspended solids to settle for 15 min ± 5 min.
Rinse the part of filtration device (see 6.2.10), which is in contact with the eluate with nitric acid (see 6.1.3),
and flush with ultra pure water (see 6.1.1). before any use.
Filter the suspension through a 0,45 µm membrane filter (see 6.2.5) using the filtration device (see 6.2.10).
Proceed immediately with the eluate treatment
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