Characterization of sludges - Filtration properties - Part 4: Determination of the drainability of flocculated sludges

This European Standard specifies a method for the determination of drainability of flocculated sludges. It is
applicable to sludge and sludge suspensions from:
a) storm water handling;
b) urban wastewater collecting systems;
c) urban wastewater treatment plants;
d) treating industrial wastewater similar to urban wastewater (as defined in Directive 91/271/EEC);
e) water supply treatment plants.
This method is also applicable to sludge suspensions from other origin.

Charakterisierung von Schlämmen - Filtrationseigenschaften - Teil 4: Bestimmung der Entwässerung von geflockten Schlämmen

Dieses Dokument legt ein Verfahren zur Bestimmung der Entwässerbarkeit geflockter Schlämme fest. Das Dokument gilt für Schlämme und Schlammsuspensionen aus folgenden Bereichen:
—   Behandlung von Regenwasser;
—   Kanalisationssysteme für kommunales Abwasser;
—   Anlagen für die Behandlung von kommunalem Abwasser;
—   Behandlung von industriellem Abwasser, die auf ähnliche Weise erfolgt wie die von kommunalem Abwasser (wie in der Richtlinie 91/271/EWG festgelegt);
—   Wasseraufbereitungsanlagen.
Dieses Verfahren ist auch auf Schlammsuspensionen anderer Herkunft anwendbar.

Caractérisation des boues - Propriétés de filtration - Partie 4 : Détermination de l'aptitude à l'égouttage des boues floculées

Le présent document spécifie une méthode de détermination de l’aptitude à l’égouttage des boues floculées. Il s’applique aux boues et aux suspensions concentrées issues :
-   de la collecte des eaux pluviales ;
-   de systèmes de collecte des eaux usées urbaines ;
-   de stations d’épuration des eaux usées urbaines ;
-   de l’épuration des eaux usées industrielles semblables aux eaux usées urbaines (définie dans la Directive 91/271/CEE) ;
-   d’usines de production d’eau potable.
Cette méthode s’applique aussi aux suspensions concentrées d’origines différentes.

Karakterizacija blata - Lastnosti filtriranja - 4. del: Določevanje odcejalnih sposobnosti izkosmičenega blata

Ta evropski standard določa metodo za določevanje prepustnosti kosmičenega blata. Uporablja se za
blato in suspenzije blata iz:
a) ravnanja z vodo ob neurjih;
b) komunalnih odpadnih vod iz kanalizacijskih sistemov;
c) čistilnih naprav za komunalno odpadno vodo;
d) čiščenja industrijske odpadne vode na podoben način kot komunalne odpadne vode (kot je opredeljeno v Direktivi 91/271/EGS);
e) čistilnih naprav za sistem oskrbe z vodo. Ta metoda se uporablja tudi za suspenzije blata drugega izvora.

General Information

Status
Published
Public Enquiry End Date
04-Aug-2017
Publication Date
11-Mar-2019
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
07-Feb-2019
Due Date
14-Apr-2019
Completion Date
12-Mar-2019

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Charakterisierung von Schlämmen - Filtrationseigenschaften - Teil 4: Bestimmung der Entwässerung von geflockten SchlämmenCaractérisation des boues - Propriétés de filtration - Partie 4 : Détermination de l'aptitude à l'égouttage des boues floculées13.030.20Liquid wastes. SludgeICS:Ta slovenski standard je istoveten z:EN 14701-4:2018SIST EN 14701-4:2019en,fr,de01-april-2019SIST EN 14701-4:2019SLOVENSKI
STANDARDSIST EN 14701-4:20101DGRPHãþD



SIST EN 14701-4:2019



EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14701-4
December
t r s z ICS
s uä r u rä t r Supersedes EN
s v y r sæ vã t r s rEnglish Version
Characterization of sludges æ Filtration properties æ Part
vã Determination of the drainability of flocculated sludge Caractérisation des boues æ Propriétés de filtration æ Partie
v ã Détermination de l 5aptitude à l 5égouttage des boues floculées
Charakterisierung von Schlämmen æ Filtrationseigenschaften æ Teil
vã Bestimmung der Entwässerbarkeit geflockter Schlämme This European Standard was approved by CEN on
w November
t r s zä
egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä
translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä
CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Serbiaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä
EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Rue de la Science 23,
B-1040 Brussels
9
t r s z CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN
s v y r sæ vã t r s z ESIST EN 14701-4:2019



EN 14701-4:2018 (E) 2 Contents Page European foreword . 3 Introduction . 4 1 Scope . 5 2 Normative references. 5 3 Terms and definitions . 5 4 Sludge conditioning . 6 5 Principle . 6 6 Apparatus . 6 7 Procedure . 6 8 Expression of results . 7 9 Calculation of the drainability index . 7 10 Test report . 9 11 Precision . 9 Annex A (informative)
Typical gravity drainage cell . 10 Annex B (informative)
Quantity of sludge in a gravity belt filtration . 11 Annex C (informative)
Results of validation trials . 12 Annex D (informative)
Use of drainability index . 16 Bibliography . 18
SIST EN 14701-4:2019



EN 14701-4:2018 (E) 3 European foreword This document (EN 14701-4:2018) has been prepared by Technical Committee CEN/TC 308 “Characterization and management of sludge”, 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 June 2019 and conflicting national standards shall be withdrawn at the latest by June 2019. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 14701-4:2010. EN 14701, Characterization of sludges — Filtration properties consists of the following parts:
— Part 1: Capillary suction time (CST); — Part 2: Determination of the specific resistance to filtration; — Part 3: Determination of the compressibility; — Part 4: Determination of the drainability of flocculated sludges. According to the CEN-CENELEC Internal Regulations, the national standards organizations 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, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 14701-4:2019



EN 14701-4:2018 (E) 4 Introduction The determination of drainability of flocculated sludge is an important parameter for evaluating their ability to be thickened by means of a draining process. It gives indications for the choice of flocculant or their dosage in view of the thickening of the sludge through a filtering medium. These easy and quick tests are the best means to narrow the number of products to be tested in full scale experiments and to adapt the pre-treatment to the sludge variability. The results of measurements obtained are the mass of filtrate collected in a standard time or the time required to recover a given volume of filtrate (commonly 50 % of the water content of the sludge), the maximum volume of filtrate and the corresponding wet and dry mass of the sludge, the undissolved solids remaining in the filtrate and the best flocculant and its optimum dose in the case of comparative tests. In order to ease the comparison of products and their dosing, an adimensional number gathering the different information obtained during a drainage test: kinetics data of filtrate release, filtrate and thickened sludge quality can be used. SIST EN 14701-4:2019



EN 14701-4:2018 (E) 5 1 Scope This document specifies a method for the determination of drainability of flocculated sludge. It is applicable to sludge and sludge suspensions from: — storm water handling; — urban wastewater collecting systems; — urban wastewater treatment plants; — treating industrial wastewater similar to urban wastewater (as defined in Directive 91/271/EEC); — water supply treatment plants. This method is also applicable to sludge suspensions from other origins. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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 872, Water quality — Determination of suspended solids — Method by filtration through glass fibre filters EN 14742, Characterization of sludges — Laboratory chemical conditioning procedure EN 15934, Sludge, treated biowaste, soil and waste — Calculation of dry matter fraction after determination of dry residue or water content EN 16323, Glossary of wastewater engineering terms 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 16323 and the following apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses:
IEC Electropedia: available at http://www.electropedia.org/
ISO Online browsing platform: available at http://www.iso.org/obp 3.1 drainability ability of treated sludge to separate from sludge liquor by gravity filtration 3.2 flocculation coagulation by means of inorganic flocculants or organic ones (polyelectrolytes) SIST EN 14701-4:2019



EN 14701-4:2018 (E) 6 4 Sludge conditioning For flocculation, the sludge will be mixed with flocculant in repeatable and quantified conditions according to EN 14742 for a laboratory preparation or sampled already flocculated. 5 Principle A given volume of flocculated sludge is poured in a filter cell, the mass of filtrate collected is recorded versus time and the corresponding wet and dry mass of the sludge retained on the filtering medium and the undissolved solids remaining in the filtrate are measured. 6 Apparatus Ordinary laboratory apparatus and the following (see Annex A): 6.1 Transparent tube (e.g. glass, polyethylene, etc.) of 150 mm diameter and of about 200 mm height. It is supported by a system composed of a filtering medium tightened in a device equipped with an appropriate sealing joint. 6.2 Filtering medium whose characteristics shall be the same of that used in the full scale drainage device and in comparative tests. 6.3 Filtrate draining device fixed under the filtering medium. 6.4 Beaker for the filtrate collection. 6.5 Weighing balance with an accuracy of at least 0,1 g connected to a computer to continuously record the cumulative mass of filtrate collected over time. The software will be able to record data every 0,5 s. 6.6 Apparatus for the determination of dry solids content of the sludge retained on the filtering medium (see EN 15934). 6.7 Apparatus for the determination of suspended solids in the filtrate (see EN 872). To allow a correct interpretation of data, the comparison of flocculation conditions should be made with the same test equipment. 7 Procedure a) Prepare the balance and the software to record the mass of filtrate as soon as the first drops of filtrate are collected. b) Measure the water content of the flocculated sludge. c) Prepare (1± 0,2) l of flocculated sludge and record the exact mass. d)
Gently pour (without shaking) the flocculated sludge in the centre of the cell for the sludge to recover the whole surface of the filtering medium. e) Record the cumulative mass of filtrate collected over time every 0,5 s at least during the first 30 s. f) Stop the test when the mass of filtrate to initial mass of sludge ratio is constant to within 0,1 g or after 10 min. g) Measure the concentration of suspended solids in the filtrate, according to EN 872, and the wet and dry mass of the sludge retained on the filter medium, according to EN 15934. SIST EN 14701-4:2019



EN 14701-4:2018 (E) 7 8 Expression of results Plot adimensional mass ratio versus time: 0mm = f (t) (1) where m is the mass of filtrate, in g; m0 is the initial mass of sludge, in g; t is the time of experiment, in s. Record the following data obtained for each test: a) adimensional mass ratio of filtrate recovered at t = 30 s, t = 90 s and at the end of the test; b) reference time necessary to collect a volume of filtrate corresponding to 50 % of the water content of the sludge; c) dryness of the cake retained on the filtering medium; d) dry mass of suspended solids per unit volume of filtrate. NOTE The optimal operating conditions are those for which the drainage is the fastest to remove the maximal drainable quantity of water, the mass of wet and dry solids retained on the filter medium is the highest, and the mass of suspended solids in the filtrate is the lowest. 9 Calculation of the drainability index The specific time required to recover 90 % of the total mass of filtrate determined as illustrated in Figure 1, the final sludge dryness after thickening and the solids content in the filtrate allow the calculation of the drainability index (Eg) which is the ratio of 3 parameters: — Solids concentration factor assessed by the ratio of the thickened sludge dryness (Sif, %) at the end of the test and the initial solids content of the sludge (Si0, %). =f10SiPSi (2) — Drainage kinetics parameter assessed by the measurement of the time required to recover 90 % of the total mass of filtrate (t90, s) as illustrated Figure 1. An adimensional number was defined by dividing this time (expressed in seconds) by a sizing parameter of belt thickener which is equal to 60 s for classical industrial machines. =90260tP (3) — The filtrate quality parameter (P3) defined, as the ratio between the residual concentration of suspended matter in the
...

SLOVENSKI STANDARD
oSIST prEN 14701-4:2017
01-julij-2017
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Charakterisierung von Schlämmen - Filtrationseigenschaften - Teil 4: Bestimmung der
Entwässerung von geflockten Schlämmen
Caractérisation des boues - Propriétés de filtration - Partie 4 : Détermination de l'aptitude
à l'égouttage des boues floculées
Ta slovenski standard je istoveten z: prEN 14701-4
ICS:
13.030.20 7HNRþLRGSDGNL%ODWR Liquid wastes. Sludge
oSIST prEN 14701-4:2017 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 14701-4:2017

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oSIST prEN 14701-4:2017


DRAFT
EUROPEAN STANDARD
prEN 14701-4
NORME EUROPÉENNE

EUROPÄISCHE NORM

June 2017
ICS 13.030.20 Will supersede EN 14701-4:2010
English Version

Characterization of sludges - Filtration properties - Part 4:
Determination of the drainability of flocculated sludges
Caractérisation des boues - Propriétés de filtration - Charakterisierung von Schlämmen -
Partie 4 : Détermination de l'aptitude à l'égouttage des Filtrationseigenschaften - Teil 4: Bestimmung der
boues floculées Entwässerbarkeit geflockter Schlämme
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 308.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.


EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 14701-4:2017 E
worldwide for CEN national Members.

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oSIST prEN 14701-4:2017
prEN 14701-4:2017 (E)
Contents Page
Foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references. 5
3 Terms and definitions . 5
4 Sludge conditioning . 5
5 Principle . 6
6 Apparatus . 6
7 Procedure . 6
8 Expression of results . 7
9 Test report . 8
10 Precision . 9
Annex A (informative) Typical gravity drainage cell . 10
Annex B (informative) Quantity of sludge in a gravity belt filtration . 11
Annex C (informative) Results of validation trials . 12
Annex D (informative) Results of validation trials . 16
Bibliography . 18
2

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oSIST prEN 14701-4:2017
prEN 14701-4:2017 (E)
Foreword
This document (prEN 14701-4:2017) has been prepared by Technical Committee CEN/TC 308
“Characterization of sludges”, the secretariat of which is held by AFNOR.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 14701-4:2010.
Other parts of this European Standard are:
— Part 1: Capillary suction time (CST);
— Part 2: Determination of the specific resistance to filtration;
— Part 3: Determination of the compressibility.
3

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oSIST prEN 14701-4:2017
prEN 14701-4:2017 (E)
Introduction
The determination of drainability of flocculated sludge is an important parameter for evaluating their
suitability to be thickened by means of a draining process. It also gives indications for the choice of
flocculant or their dosage in view of the thickening of the sludge through a filtering medium. These easy
and quick tests are the best means to narrow the number of products to be tested in full scale
experiments and to adapt the pre-treatment to the sludge variability.
The results obtained are the mass of filtrate collected in a standard time or the time required to recover
a given volume of filtrate (commonly 50 % of the water content of the sludge), the maximum volume of
filtrate and the corresponding wet and dry mass of the sludge, the undissolved solids remaining in the
filtrate and the best flocculant and its optimum dose in the case of comparative tests. In order to ease
the comparison of products and their dosing, an adimensional number gathering the different
information obtained during a drainage test: kinetics data of filtrate release, filtrate and thickened
sludge quality can be used.
4

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oSIST prEN 14701-4:2017
prEN 14701-4:2017 (E)
1 Scope
This document specifies a method for the determination of drainability of flocculated sludge. It is
applicable to sludge and sludge suspensions from:
— storm water handling;
— urban wastewater collecting systems;
— urban wastewater treatment plants;
— treating industrial wastewater similar to urban wastewater (as defined in Directive 91/271/EEC);
— water supply treatment plants.
This method is also applicable to sludge suspensions from other origin.
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 872, Water quality — Determination of suspended solids — Method by filtration through glass fibre
filters
EN 12832, Characterization of sludge — Utilization and disposal of sludge — Vocabulary
EN 12880, Characterization of sludges — Determination of dry residue and water content
EN 14742, Characterization of sludges — Laboratory chemical conditioning procedure
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 12832 and the following apply.
3.1
drainability
ability of treated sludge to separate from sludge liquor by gravity filtration
3.2
flocculation
coagulation by means of inorganic flocculants or organic ones (polyelectrolytes)
4 Sludge conditioning
For flocculation, the sludge will be mixed with flocculant in repeatable and quantified conditions
according to EN 14742 for a laboratory preparation or sampled already flocculated.
5

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oSIST prEN 14701-4:2017
prEN 14701-4:2017 (E)
5 Principle
A given volume of flocculated sludge is poured in a filter cell, the mass of filtrate collected is recorded
versus time and the corresponding wet and dry mass of the sludge retained on the filtering medium and
the undissolved solids remaining in the filtrate are measured.
6 Apparatus
Ordinary laboratory apparatus and the following (see Annex A, informative):
6.1 Transparent tube (e.g. glass, polyethylene, etc.) of 150 mm diameter and of about 200 mm height.
It is supported by a system composed of a filtering medium tightened in a device equipped with an
appropriate sealing joint.
6.2 Filtering medium whose characteristics shall be the same of that used in the full scale drainage
device and in comparative tests.
6.3 Filtrate draining device fixed under the filtering medium.
6.4 Beaker for the filtrate collection.
6.5 Weighing balance with an accuracy of at least 0,1 g connected to a computer to continuously
record the cumulative mass of filtrate collected over time. The software will be able to record data every
0,5 s.
6.6 Apparatus for the determination of dry solids content of the sludge retained on the filtering
medium.
6.7 Apparatus for the determination of suspended solids in the filtrate.
To allow a correct interpretation of data, the comparison of flocculation conditions should be made with
the same test equipment.
7 Procedure
a) Prepare the balance and the software to record the mass of filtrate as soon as the first drops of
filtrate are collected.
b) Measure the water content of the flocculated sludge.
c) Gently pour (without shaking) 1 l ± 0,2 l of flocculated sludge (record the exact mass) in the centre
of the cell for the sludge to recover the whole surface of the filtering medium.
d) Record the cumulative mass of filtrate collected over time every 0,5 s at least during the first 30 s.
e) Stop the test when the mass of filtrate to initial mass of sludge ratio is constant to within 0,1 g or
after 10 min.
f) Measure the concentration of suspended solids in the filtrate (see EN 872) and the wet and dry
mass of the sludge retained on the filter medium (see EN 12880).
g) Repeat steps a) to f) for at least two times if repeatability measurements are needed.
6

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oSIST prEN 14701-4:2017
prEN 14701-4:2017 (E)
8 Expression of results
M
Plot adimensional mass versus time: = f t
( )
M
0
where
M is the mass of filtrate, in g;
M is the initial mass of sludge, in g;
0
t is the time of experiment, in s.
Record the following data obtained for each test:
a) adimensional mass of filtrate recovered at t = 30 s, t = 90 s and at the end of the test;
b) time necessary to collect a volume of filtrate corresponding to 50 % of the water content of the
sludge;
c) dryness of the cake retained on the filtering medium;
d) dry mass of suspended solids per unit volume of filtrate.
NOTE The optimal operating conditions are those for which the drainage is the fastest to remove the maximal
drainable quantity of water, the mass of wet and dry solids retained on the filter medium is the highest, and the
mass of suspended solids in the filtrate is the lowest.
The time required to recover 90 % of the total mass of filtrate determined as illustrated Figure 1, the
final sludge dryness after thickening and the solids content in the filtrate allow the calculation of the
drainability index (E ) which is the ratio of 3 parameters:
g
— Solids concentration factor assessed by the ratio of the thickened sludge dryness at the end of the
Si
f
test and the initial solids content of the sludge. P =
1
Si
0
— Drainage kinetics parameter assessed by the measurement of the time required to recover 90 % of
the total mass of filtrate as illustrated Figure 1. An adimensional number was defined by dividing
this time by a sizing parameter of belt thickener which is equal to 60 s for classical industrial
t
90
machines. P =
2
60
— The filtrate quality parameter (P ) defined, as the ratio between the residual concentration of
3
SM
r
suspended matters in the filtrate and the initial solids content of the sludge.
P =
3
Si
0
7

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oSIST prEN 14701-4:2017
prEN 14701-4:2017 (E)

Figure 1 — Determination of t with a classical drainage curve
90
The drainage index (E ) is expressed by the following formula as discussed in [2]:
g


Si
f


P Si
1 0

E ln( ) ln
g
β 1
α

PP×
23
 4
t SM
90 3 r
() ×



60 Si
0


Annex D gives information about the use of drainability index for drainage process optimization.
9 Test report
The test report shall contain the following
...

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