1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 14701-2:2013Characterisation of sludges Filtration propertiesPart 2: Determination of the specificresistance to filtrationBS EN 14701-2:2013 BRITISH STANDARDNational forewo
2、rdThis British Standard is the UK implementation of EN 14701-2:2013.It supersedes BS EN 14701-2:2006 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee EH/5, Sludge characterization.A list of organizations represented on this committee can beobtained on re
3、quest to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 78076 9ICS 13.030.20Compliance with a British
4、Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 May 2013.Amendments issued since publicationDate Text affectedBS EN 14701-2:2013EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 14701
5、-2 April 2013 ICS 13.030.20 Supersedes EN 14701-2:2006English Version Characterisation of sludges - Filtration properties - Part 2: Determination of the specific resistance to filtration Caractrisation des boues - Proprits de filtration - Partie 2: Dtermination de la rsistance spcifique la filtratio
6、n Charakterisierung von Schlmmen - Filtrationseigenschaften - Teil 2: Bestimmung des spezifischen Filtrationswiderstands This European Standard was approved by CEN on 1 March 2013. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving thi
7、s European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official v
8、ersions (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 Austr
9、ia, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden
10、, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2013 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Mem
11、bers. Ref. No. EN 14701-2:2013: EBS EN 14701-2:2013EN 14701-2:2013 (E) 2 Contents Page Foreword 3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms and definitions .5 4 Principle 5 5 Apparatus .6 6 Procedure .6 6.1 General 6 6.2 Reduced pressure (Figure B.1) 6 6.3 Under pressure (Figure B.2
12、 a) .7 6.4 Under pressure with a piston (Figure B.2 b) 7 7 Expression of results 8 8 Precision 10 9 Test report . 10 Annex A (informative) Supplementary information to Darcys law . 11 Annex B (informative) Filtration apparatus . 13 Annex C (informative) Table of viscosity . 15 Annex D (informative)
13、Result of validation trial 16 Bibliography . 20 BS EN 14701-2:2013EN 14701-2:2013 (E) 3 Foreword This document (EN 14701-2:2013) has been prepared by Technical Committee CEN/TC 308 “Characterization of sludges”, the secretariat of which is held by AFNOR. This European Standard shall be given the sta
14、tus of a national standard, either by publication of an identical text or by endorsement, at the latest by October 2013, and conflicting national standards shall be withdrawn at the latest by October 2013. Attention is drawn to the possibility that some of the elements of this document may be the su
15、bject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 14701-2:2006. Other parts of EN 14701 are: Part 1: Capillary suction time (CST); Part 3: Determination of the compressibility; Part 4: Determination of
16、the drainability of flocculated sludges. Most significant changes made since the latest edition: “Part 4 ” added to Foreword; Introduction modified; CEN/TR 14742 added to Normative References; Clause “Principle” modified and better specified; List Entry 5.1.3 modified and better specified; List Entr
17、y 5.8 added; Clause 6 better specified; In Formula (1), “m” instead of “Co”; Table 1 simplified; text added in Clause 7; List Entry c) added in Clause 9; former Annex A deleted; bibliographical references added. According to the CEN-CENELEC Internal Regulations, the national standards organisations
18、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, Ne
19、therlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 14701-2:2013EN 14701-2:2013 (E) 4 Introduction The specific resistance to filtration is a parameter which indicates the suitability of sludge to be filtered. The value o
20、f the specific resistance to filtration has great importance in filtration processes as it can be useful for estimating the performance of full-scale filtering devices, mainly pressure filters, and comparing filterability characteristics of sludges produced in different plants. Specific resistance m
21、easurements can also give indications on both the optimal type and dosage of conditioner to be used (CEN/TR 14742). This revised version only includes editorial changes that do not influence the original, validated method. BS EN 14701-2:2013EN 14701-2:2013 (E) 5 1 Scope This European Standard specif
22、ies a method for determining the specific resistance to filtration of conditioned and non-conditioned sludges, provided that no sedimentation occurs during filtration (i.e. single phase suspension with particles in suspension). This European Standard is applicable to sludges and sludge suspensions f
23、rom: storm water handling; urban wastewater collecting systems; urban wastewater treatment plants; industrial wastewater that has been treated similarly to urban wastewater (as defined in Directive 91/271/EEC); water supply treatment plants. This method is also applicable to sludge and sludge suspen
24、sions of other origins. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced docum
25、ent (including any amendments) applies. EN 12832:1999, Characterization of sludges Utilization and disposal of sludges Vocabulary EN 12880, Characterization of sludges Determination of dry residue and water content CEN/TR 14742, Characterization of sludges Laboratory chemical conditioning procedure
26、3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 12832:1999 and the following apply. 3.1 specific resistance to filtration property representing the resistance to filtration of a layer of particles having a unit mass of dry solids deposited on a unit f
27、iltering area 4 Principle This method is based on the flow of a liquid through a porous medium in accordance with Darcys law (see Annex A). The specific resistance to filtration is determined by pouring a suitable volume of sludge into a filtering device, allowing the liquid to be filtered under con
28、stant vacuum or pressure, whilst recording the amount of filtrate over time. Considering that for sludges this parameter is affected by pressure value, this standard has been validated for the determination of specific resistance to filtration at pressure values (50 5) kPa, (150 10) kPa and (300 15)
29、 kPa, as specifically indicated in Clause 6. If necessary, as in the case of tests intended to size or optimise industrial filters, tests may be carried out at different pressures, provided results have been validated in advance. BS EN 14701-2:2013EN 14701-2:2013 (E) 6 5 Apparatus 5.1 Filtration app
30、aratus with a capacity of 250 ml, and filter diameters between 60 mm and 90 mm (see Annex B). 5.1.1 Apparatus for filtration under reduced pressure (see Figure B.1). 5.1.2 Apparatus for filtration under pressure up to 1 MPa (see Figure B.2 a). 5.1.3 Apparatus for filtration under pressure up to 1 MP
31、a with a piston (see Figure B.2 b) equipped with a pressure sensor under the piston to measure the actual applied pressure. If this set-up is not given, piston friction is not taken into account in the pressure measurement and air filtration is preferred. 5.2 Graduated cylinders with a capacity of 1
32、00 ml and 250 ml. 5.3 Vacuum pump, or air pressure system, or hydraulic system for pressure application, including pressure adjustment system (regulator or reducer) and pressure gauge. 5.4 Chronometer, e.g. stopwatch, computer. 5.5 Beaker with a capacity of 500 ml. 5.6 Pipettes. 5.7 Filtering medium
33、, filter paper (extra fast, ash-free), with a particle retention between 20 m and 25 m and a filtration flow rate of about 100 ml/min and a thickness of 0,22 mm (e.g. Whatman 411). Synthetic, or stainless metallic cloth may also be used if they can be shown to lead to the same results. 5.8 Filtering
34、 medium support. 5.9 Apparatus for determining sludge dry residue and water content (see EN 12880). 5.10 Thermostatic cell, for determinations at non-ambient temperatures. 6 Procedure 6.1 General Measure the dry residue of the sludge, Co, in accordance with EN 12880 and assume that the dry residue m
35、easured in g/kg is equivalent to the concentration measured in g/l. Prior to measuring, ensure the sludge is at room or test temperature. If sludge has to be conditioned, this operation shall be carried out according to CEN/TR 14742. 6.2 Reduced pressure (Figure B.1) 6.2.1 Keep the valve between fil
36、ter (5.1) and vacuum/pressure system (5.3) closed during the procedure, maintaining the system at an absolute pressure of (50 5) kPa. 1) This information is given for the convenience of users of this document and does not constitute an endorsement by CEN of the product named. Equivalent products may
37、 be used if they can be shown to lead to the same results. BS EN 14701-2:2013EN 14701-2:2013 (E) 7 6.2.2 Put the filtering medium (5.7) in the funnel, moisten it with water and avoid any air entrance into the filter. 6.2.3 Measure the temperature, put (100 1) ml of non-conditioned sludge or (200 2)
38、ml of conditioned, or of easily filterable sludge into the funnel after gentle homogenisation by pouring the sludge 3 times to 4 times from one beaker to another (only in case of non-conditioned sludge), open the valve and start filtration. 6.2.4 Record filtrate volumes, V, and corresponding times,
39、t, only after collecting at least 10 % of the initial filtrate volume. Recording depends on flow rate and could range from every 5 s at the beginning until every 60 s or more (for sludge of low filterability) at the end. Stop the filtration when one of the following conditions occurs: pressure drops
40、 down (breaking of cake); filtrate flow rate instantaneously drops down; plot t/V vs. V deviates from linearity; filtration time exceeds 60 min. 6.2.5 Measure the dry mass of the cake after filtration in accordance with EN 12880, and measure the dynamic viscosity of the filtrate at test temperature.
41、 6.3 Under pressure (Figure B.2 a) 6.3.1 While keeping the valve between the filter (5.1) and the air pressure system (5.3) closed, adjust the system to (50 5) kPa, or (150 10) kPa, or (300 15) kPa above atmospheric pressure. The pressure shall be constantly maintained during the whole procedure. 6.
42、3.2 Put the filtering medium (5.7) into the filtration cell, moisten it with water and avoid any air entrance into the filter. 6.3.3 Measure the temperature and put 100 ml of non-conditioned sludge or 200 ml of conditioned, or of easily filterable sludge into the apparatus after gentle homogenisatio
43、n by pouring the sludge 3 times to 4 times from one beaker to another (only in case of non-conditioned sludge). 6.3.4 Close the sludge inlet, open the valve of the air pressure system and start the filtration process. 6.3.5 Record filtrate volumes, V, and corresponding times, t, only after collectin
44、g at least 10 % of the initial filtrate volume. Recording depends on flow rate and could range from every 5 s at the beginning until every 60 s or more (for sludge of low filterability) at the end. Stop the filtration when one of the following conditions occurs: pressure drops down (breaking of cake
45、); instantaneous filtrate flow rate drops down; plot t/V vs. V deviates from linearity; filtration time exceeds 60 min. 6.3.6 Measure the dry mass of the cake after filtration in accordance with EN 12880 and measure the dynamic viscosity of the filtrate at test temperature. 6.4 Under pressure with a
46、 piston (Figure B.2 b) 6.4.1 Follow the procedure as described in 6.3.1 to 6.3.3. BS EN 14701-2:2013EN 14701-2:2013 (E) 8 6.4.2 Close the sludge inlet. 6.4.3 Insert the piston into the filtration cell. Make sure that the piston is in close contact with the sludge surface by purging the air through t
47、he air outlet. 6.4.4 Close the air outlet and close the filtration system. 6.4.5 Open the pressure system valve and start filtration. 6.4.6 Record filtrate volumes, V, and corresponding times, t, only after collecting at least 10 % of the initial filtrate volume. Recording depends on flow rate and c
48、ould range from every 5 s at the beginning until every 60 s or more (for sludge of low filterability) at the end. Stop the filtration when one of the following conditions occurs: pressure measured by the sensor drops down (beginning of the compression phase); plot t/V vs. V deviates from linearity;
49、filtration time exceeds 60 min. 6.4.7 Measure the dry mass of the cake after filtration in accordance with EN 12880 and dynamic viscosity of filtrate at test temperature. NOTE In 6.2 to 6.4, it is assumed that the volume of the cake can be neglected. In 6.2 to 6.4, results of tests carried out at different pressures have to be validated in advance. 7 Expression of results For the calculation of the specific resistance to filtration, r, Formula (1) is used: mbApr=22
