1、BRITISH STANDARDBS EN 14701-1:2006Characterization of sludges Filtration properties Part 1: Capillary suction time (CST)The European Standard EN 14701-1:2006 has the status of a British StandardICS 13.030.20g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g
2、49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 14701-1:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2007 BSI 2007ISBN 978 0 580 50510 2National forewordThis Bri
3、tish Standard was published by BSI. It is the UK implementation of EN 14701-1:2006.The UK participation in its preparation was entrusted to Technical Committee EH/5, Sludge characterization.A list of organizations represented on EH/5 can be obtained on request to its secretary.The UK committee has n
4、ever seen the need to standardize this method at a European level and, as a consequence, has not been actively involved in the development of this standard. However, the UK committee is pleased that a classic British method was selected. The method has long been used as a valuable operational-contro
5、l method and is available in existing technical literature (see reference 1 in the bibliography of this standard). Due to the difficulty and cost of sending liquid sludge samples (in such a manner that their properties do not change) to laboratories for international interlaboratory trials of the pe
6、rformance of this method, interested parties convened at a workshop to assess the test. Their conclusion was that the results are operationally defined (e.g. by the filter paper used) and, as the document does not specify all such operational details, the performance data are not really applicable o
7、utside the context of the workshop. As a result, the members of EH/5 have no information to offer on the reproducibility of the results.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British
8、 Standard cannot confer immunity from legal obligations. Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 14701-1March 2006ICS 13.030.20English VersionCharacterization of sludges - Filtration properties - Part 1:Capillary suction time (CST)Ca
9、ractrisation des boues - Proprits de filtration - Partie1: Dtermination du temps de succion capillaireCharakterisierung von Schlmmen -Filtrationseigenschaften - Teil 1: Bestimmung der kapillarenFliezeitThis European Standard was approved by CEN on 3 February 2006.CEN members are bound to comply with
10、 the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat
11、or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversio
12、ns.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, S
13、witzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No.
14、EN 14701-1:2006: EEN 14701-1:2006 (E) 2 Contents Page Foreword3 1 Scope 5 2 Normative references 5 3 Terms and definitions .5 4 Principle5 5 Apparatus .6 5.1 Standard apparatus .6 5.2 Filter paper .6 5.3 Beakers .6 6 Procedure .6 7 Expression of results 6 8 Precision.7 9 Test report 7 Annex A (infor
15、mative) Simple automatic instrument for determining the filterability of sewage sludge .8 Annex B (informative) Relation between CST and the specific resistance to filtration .9 Annex C (informative) Relation between CST and solids content .10 Annex D (informative) Table of dynamic viscosity 11 Anne
16、x E (informative) Results of validation trials .12 Bibliography 15 EN 14701-1:2006 (E) 3 Foreword This document (EN 14701-1:2006) 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 st
17、atus of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2006, and conflicting national standards shall be withdrawn at the latest by September 2006. Other parts of this European Standard are: Part 2: Determination of the specific resistan
18、ce to filtration; Part 3: Determination of the compressibility. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, Franc
19、e, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 14701-1:2006 (E) 4 Introduction The capillary suction time (CST) is a fast and simple way
20、to evaluate the sludge dewaterability by filtration. This method gives no information on the obtainable solids content in a dewatering process. The measurement of CST should also make possible the evaluation, although only qualitatively, of other sludge characteristics, including dewaterability by c
21、entrifugation. EN 14701-1:2006 (E) 5 1 Scope This document specifies a method for the determination of the capillary suction time. This document is applicable to sludge and sludge suspensions from: storm water handling; urban wastewater collecting systems; urban wastewater treatment plants; treating
22、 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 docu
23、ment. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 12832:1999, Characterization of sludges Utilization and disposal of sludges Vocabulary 3 Terms and definitions For the purposes of
24、this document, the terms and definitions given in EN 12832:1999 and the following apply. 3.1 filterability property indicating the amenability of a sludge to be dewatered by a filtration process 3.2 capillary suction time (CST) measurement of the time for a wetting front in a filter paper to travel
25、between two fixed points 4 Principle The principle of the method is that dewatering is achieved by the suction applied to the sludge by the capillary action of an absorbent filter paper. A part of the absorbent paper area is exposed to the sludge, while the remaining area is free for absorbing the f
26、iltrate. The rate at which the paper becomes wetted with filtrate is a measure correlated to sludge dewaterability: it is measured by the time necessary for the filtrate to cover the space between two probes which detect the advancement of the liquid front on the paper (Annex A informative). The CST
27、 measurements are strongly affected by many factors, such as properties of the paper, surface tension, temperature, suspended solids concentration, so they give only qualitative and comparative evaluations which can be correlated to the specific resistance to filtration (prEN 14701-2) for a given ty
28、pe of sludge (Annex B informative). EN 14701-1:2006 (E) 6 5 Apparatus 5.1 Standard apparatus Device consisting of: a) filtration apparatus, including base for supporting the absorbent paper, sludge reservoir and probes; b) automatic time recording unit, including amplifier and digital electric stop-
29、clock recording in seconds (see Annex A informative). 5.2 Filter paper Paper suitable for chromatography with grain parallel with the longer side (for instance, Whatman n. 17 or Wickam CST Papers 7 cm x 9 cm code 8680841). NOTE For comparable results the same filter paper type should be used. 5.3 Be
30、akers Conventional beakers, 50 ml minimum. 6 Procedure 6.1 Place a filter paper in the apparatus. The filter paper shall always be placed with the same side up. 6.2 Mix the sludge to be tested by pouring it off from a beaker to another for 4 times. 6.3 Pour immediately the mixed sludge into the rese
31、rvoir until it is completely full. Great attention shall be paid in performing measurements immediately after the sludge mixing to avoid any result unreliability due to sludge settling into the beaker (especially for conditioned sludges). 6.4 When the clock stops, register the time which has been au
32、tomatically measured. 6.5 Repeat steps 6.1 to 6.4 in order to have at least 3 significant values, as stated in Clause 7. 7 Expression of results The CST value is given by arithmetically averaging the measured values. If one or more values differ of more than 20% from the calculated mean value, they
33、must not be considered and the average shall be calculated again with remaining values: in any case valid values shall be, at least, 3. The influence of the temperature may be evaluated through the relationship: CST1= (1/2) CST2(1) where 1and 2are the dynamic viscosities of water at the two consider
34、ed temperatures. 1) This information is given for the convenience of users of this document and does not constitute an endorsement by CEN of this product. Equivalent products may be used if they can be shown to lead to the same results. EN 14701-1:2006 (E) 7 If the room temperature is between 12 C a
35、nd 30 C, the influence of the temperature can be neglected. Water viscosities as a function of temperature are reported in the table in Annex D (informative). 8 Precision Results of validation trials are summarized in Annex E (informative). The repeatability standard deviation ranges from 0,411 s (3
36、,6 %) for activated/thickened sewage sludge, to 0,463 s (4,4 %) for activated sewage sludge, to 1,560 s (3,4 %) for waterworks sludge, and to 7,856 s (5,3 %) for digested sewage sludge. Mean value is 2,573 s (4,9 %). Minimum precision is 5,3 %. The reproducibility standard deviation ranges from 0,64
37、3 s (5,6 %) for activated/thickened sewage sludge, to 1,043 s (9,9 %) for activated sewage sludge, to 2,023 s (4,4 %) for waterworks sludge, and to 20,01 s (14,0 %) for digested sewage sludge. Mean value is 5,929 s (11,3 %). Minimum precision is 14,0 %. 9 Test report The test report shall contain th
38、e following information: a) reference to this document; b) all information necessary for the complete identification of the sludge sample; c) details of sample pre-treatment, if carried out; d) information about the size of the reservoir used; e) results of the determination according to Clause 7; f
39、) any detail not specified in this document or which are optional and any other factor which may have affected the results. EN 14701-1:2006 (E) 8 Annex A (informative) Simple automatic instrument for determining the filterability of sewage sludge The CST apparatus by Triton as described in 1 consist
40、s of a base supporting a rectangular piece of 7 cm x 9 cm of absorbent filter paper and a block holding probes above it; in the centre of the upper block (which stands clear of the paper by resting on five stainless steel supports) there is a circular hole in which a stainless steel reservoir (18 mm
41、 bore/25 mm high or 10 mm bore/50 mm high) loosely fit. On the under side of the upper block there are two engraved circles, of 3,2 cm and 4,5 cm in diameter, concentric with the reservoir; two of the supports are specially machined probes in line with the first concentric circle and one with the se
42、cond circle. Both probes are electrically connected to the recording unit. For this apparatus, the CST values of raw sewage sludge generally range 60 s to 300 s, using the 18 mm reservoir and the kind of papers reported before (see 5.2). The 18 mm reservoir is more suitable for low-dewaterable sludg
43、es: significant values range 10 s to 900 s. The use of the 10 mm reservoir is necessary for easily filterable sludges: significant values range 20 s to 1 200 s. For high filterable sludges, having very low CST, 2 overlapped filter papers could be used. The 10 mm reservoir can be difficult to fill, e
44、specially with thick sludges. The 18 mm reservoir has been found to be suitable for use with most sewage sludges, but other dimensions may be more suitable for other types of suspension. EN 14701-1:2006 (E) 9 Annex B (informative) Relation between CST and the specific resistance to filtration The va
45、riation of CST with specific resistance to filtration for 18 mm and 10 mm diameter reservoirs for sewage sludges is reported in Baskerville and Gale (1968) 1. The relationship between CST and the specific resistance, measured through the Buchner procedure, was also studied by Smollen (1986) 2, and S
46、pinosa et al. (1991) 3. EN 14701-1:2006 (E) 10 Annex C (informative) Relation between CST and solids content The variation of CST with solids content is discussed in Vesilind (1988) 4. EN 14701-1:2006 (E) 11 Annex D (informative) Table of dynamic viscosity Table D.1 Dynamic viscosity of water from 0
47、 C to 40 C T (C) Viscosity (10-3Pa s) T (C) Viscosity (10-3Pa s) 0 1,7921 26 0,8737 1 1,7313 27 0,8545 2 1,6728 28 0,8360 3 1,6191 29 0,8180 4 1,5674 30 0,8007 5 1,5188 31 0,7840 6 1,4728 32 0,7679 7 1,4284 33 0,7523 8 1,3860 34 0,7371 9 1,3462 35 0,7225 10 1,3077 36 0,7085 11 1,2713 37 0,6947 12 1.
48、2663 38 0,6814 13 1,2028 39 0,6685 14 1,1709 40 0,6560 15 1,1404 16 1,1111 17 1,0828 18 1,0559 19 1,0299 20 1,0050 20,2 1,0000 21 0,9810 22 0,9579 23 0,9358 24 0,9142 25 0,8937 NOTE 1 10-3Pa s = 10-2g/cm s = 1 centipoise. NOTE 2 It is assumed that filtrate viscosity is equal to water viscosity. EN 1
49、4701-1:2006 (E) 12 Annex E (informative) Results of validation trials Because the circulation of samples of real sludge high in organic content is not possible due to problems associated to changes in their physical characteristics during handling and transportation, the “Modified Round Robin Tests” procedure, developed by TG 3 of CEN/TC 308/WG 1, and reported in doc CEN/TC 308 N 822, was followed. With this procedure, the round robin tests are carried out through “circulation of analysts”, i. e. operators coming from t
