1、BRITISH STANDARDBS EN 14702-2:2006Characterization of sludges Settling properties Part 2: Determination of thickenabilityThe European Standard EN 14702-2:2006 has the status of a British StandardICS 13.030.20g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50
2、g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 14702-2:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2007 BSI 2007ISBN 978 0 580 50511 9National forewordThis Br
3、itish Standard was published by BSI. It is the UK implementation of EN 14702-2:2006.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
4、never 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-contr
5、ol 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 p
6、erformance 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
7、outside 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 Britis
8、h Standard cannot confer immunity from legal obligations.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 14702-2March 2006ICS 13.030.20English VersionCharacterization of sludges - Settling properties - Part 2:Determination of thickenabilityC
9、aractrisation des boues - Proprits de sdimentation -Partie 2: Dtermination de laptitude lpaississementCharakterisierung von Schlmmen - Absetzeigenschaften -Teil 2: Bestimmung der EindickbarkeitThis European Standard was approved by CEN on 3 February 2006.CEN members are bound to comply with the CEN/
10、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 or to any
11、 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 officialversions.CEN me
12、mbers 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, Switzerlan
13、d 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. EN 14702-
14、2:2006: EEN 14702-2:2006 (E) 2 Contents Page Foreword3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms and definitions .5 4 Principle5 5 Interferences 5 6 Apparatus .6 7 Procedure .6 8 Expression of results 6 9 Precision.6 10 Test report 7 Annex A (informative) Stirred cylinder for determ
15、ining the thickenability of sludges 8 Annex B (informative) Results of validation trials .9 Bibliography 12 EN 14702-2:2006 (E) 3 Foreword This document (EN 14702-2:2006) has been prepared by Technical Committee CEN/TC 308 “Characterization of sludges”, the secretariat of which is held by AFNOR. Thi
16、s 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 September 2006, and conflicting national standards shall be withdrawn at the latest by September 2006. Another part of this European Standard is: Part
17、1: Determination of settleability (Determination of the proportion of sludge volume and sludge volume index). 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, Cz
18、ech 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. EN 14702-2:2006 (E) 4 Introduction Determinatio
19、n of the thickenability, i.e. the further concentration of suspended (undissolved) sludge solids in settling under gravity, through the use of laboratory mechanical assisted cylinders is negatively affected by bridging, wall effects and particle size effects. Ideally, this parameter should be measur
20、ed in large-diameter columns having the same depth as the prototype thickener, but above effects can be satisfactory overcome by introducing a low-speed stirrer in a cylinder; this also helps to reduce the effect of the shallow depth. EN 14702-2:2006 (E) 5 1 Scope This document specifies a method fo
21、r the determination of the thickenability of sludge suspensions. This document is applicable to 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 9
22、1/271 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 refer
23、ences, the latest edition of the referenced document (including any amendments) applies. EN 1085:1997, Waste water treatment Vocabulary 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 1085:1997 and the following apply. 3.1 thickenability ability of sl
24、udge solids to further concentrate in mechanical assisted settling under gravity 3.2 stirred sludge volume volume of the sludge suspension after settling under specified stirring conditions 3.3 stirred sludge volume index quotient of sludge volume by the concentration by mass of dry matter in the sl
25、udge, measured in a stirred cylinder 4 Principle The thickenability is determined by the proportion of the total volume occupied by the sludge in a sludge suspension within 30 min after settling under gentle stirring in standard apparatus and under standard conditions. 5 Interferences Settling prope
26、rties vary with the solids concentration. Therefore, the comparison of these properties of sludge suspensions having different solids concentrations is allowed if a reference concentration is assumed; the EN 14702-2:2006 (E) 6 value of 3,5 g/l has been found to be the optimal one 1. Settling propert
27、ies evaluated at this solids concentration value also correlate well with the maximum solids loading at which that sludge may be applied to a tank without loss of solids in the effluent. Interference occurs when there are fairly large temperature differences between the temperature of the sample and
28、 the ambient temperature as a result of convection and formation of gas bubbles. With differences of more than 5 C it is advisable to place the settling cylinder with the sample in a bucket filled with the sample fluid. 6 Apparatus 6.1 graduated cylinder, diameter 10 cm, measuring height 50 cm, nomi
29、nal volume 3 500 ml, made of glass or transparent plastic, equipped with a low speed stirrer at 1 rpm. The stirrer is in 1 (Annex A (informative). 6.2 scoop, nominal volume 5 l. 7 Procedure A representative sample of sludge suspension is taken by the scoop and immediately poured into the graduated c
30、ylinder up to the 50 cm mark. For this purpose, a scoop holding 5 l is used. Start the stirrer and record the level of sludge-water interface in the cylinder after 30 min. For measurements at the reference concentration of 3,5 g/l, sludge samples shall be obtained through dilution by supernatant liq
31、uor followed by gentle homogenisation. 8 Expression of results The stirred sludge volume (Vss) is obtained as the quotient of the sludge volume after stirring (Clause 4) by the volume of the initial sludge sample volume. It is given in millilitres by litre as an average of at least two measurements.
32、 The stirred sludge volume index (Issv) is calculated from the equation below: ()0ssv50000 1CHI= where H is the final sludge level in centimetres; C0is the initial solids concentration, in grams per litre (see EN 12880); 50 is the starting height of sludge suspension, in centimetres; 1 000 is a conv
33、ersion factor. NOTE For activated sludges, plant values of Issvat 3,5 g/l lower than 80 ml/g are indicative of good thickenability, while values higher than 120 ml/g of poor thickenability. 9 Precision Results of validation trials are summarized in Annex B (informative). EN 14702-2:2006 (E) 7 The re
34、producibility standard deviation ranges from 0,22 ml/g (0,5 %) for digested sewage sludge, to 0,28 ml/g (1,0 %) for waterworks sludge, to 1,03 ml/g (1,1 %) for activated/thickened sewage sludge, and to 1,71 ml/g (1,8 %) for activated sewage sludge. Mean value is 0,88 ml/g (1,2 %). Minimum precision
35、is 1,8 %. 10 Test report The test report shall contain the following information: a) reference to this document; b) all information necessary for the complete identification of the sludge sample; c) details of sample preparation; e. g. dilution; d) results of the determination according to Clause 8;
36、 e) any details not specified in this document or which are optional and any other factor which may have affected the results. EN 14702-2:2006 (E) 8 Annex A (informative) Stirred cylinder for determining the thickenability of sludges The apparatus, as derived from that derived in 1, consists of a gr
37、aduated transparent cylinder, diameter 10 cm, measuring height 50 cm, equipped with a low-speed stirrer at 1 rpm. The stirrer consists of two vertical rods, diameter 0,5 cm to 0,6 cm, places asymmetrically to the cylinder axis, the first at a distance from the cylinder wall of about 0,3 cm, the seco
38、nd at a distance from the cylinder wall of about 2,5 cm, with a remaining distance between them of about 5,0 cm. EN 14702-2:2006 (E) 9 Annex B (informative) Results of validation trials Because the circulation of samples of real sludge high in organic content is not possible due to problems associat
39、ed 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
40、 analysts”, i. e. operators coming from the laboratories participating to the exercise meet in a common location, close to the place where samples are collected, and work there on same samples, each using own apparatus. Validation trials were carried out at LUA, Dsseldorf, on 29 September 2004. Tria
41、ls involved a total of 11 Operators from the following 9 Laboratories/Institutions in 3 Countries: ARPA Puglia (Bari, I), CEMAGREF (Montaldre, F), CNR-IRSA (Bari, I), Comm. Env. Emerg. in Puglia Region (Bari, I), DIN (Berlin, D), LUA-NRW (Dsseldorf, D), STUA (Lippstadt, D), UBA (Berlin, D), Universi
42、ty of Lecce (I). The following 4 different sludge types were tested: Sample 1: Sewage sludge activated Solids concentration (g/l): 2,71 Sample 2: Sewage sludge digested Dry residue (%): 2,21 Sample 3: Waterworks sludge Dry residue (%): 3,62 Sample 4: Sewage sludge activated/thickened Dry residue (%)
43、: 0,75 (analyses for measuring solids concentration and/or dry residue were carried out at the Chemical-biological Laboratory of Landeshauptstadt in Dsseldorf) Test results have been statistically analysed for the evaluation of precision according to ISO 5725-2. In particular, the repeatability stan
44、dard deviation sr(for cells containing more than one figure), and the reproducibility standard deviation sRwere calculated. The tables of results which follow contain the following symbols: i is the operator number; j is the level (sample) number; k (= 1, 2, ., n) is the test number; n are the repli
45、cates; nijis the number of test results in the cell for operator (i) at level (j); p is the total number of operators (i) (i = 1, 2, , p); q are the total testing levels (batches of materials) (j) (j = 1, 2, , q); EN 14702-2:2006 (E) 10 sris the repeatability standard deviation; sRis the reproducibi
46、lity standard deviation; ijis the cell means; y is the test result; yijkis the result of the test number (k) for operator (i) at level/sample (j). Table B.1 Readings Operator number (i) Level (j) Sample 1 Level Sample 2 Level Sample 3 Level Sample 4 (= q) values (yijk) cm mean (ij) cm values (yijk)
47、cm mean (ij) cm values (yijk) cm mean (ij) cm values (yijk) cm mean (ij) cm 1 13,0 13,0 49,1 49,1 49,3 49,3 35,4 35,4 2 13,0 13,0 49,0 49,0 49,2 49,2 3 13,0 13,0 49,0 49,0 49,3 49,3 34,7 34,7 4 13,0 13,0 49,0 49,0 49,0 49,0 5 13,2 13,2 49,2 49,2 49,4 49,4 35,5 35,5 6 49,3 49,3 7 13,5 13,5 48,9 48,9
48、49,3 49,3 8 13,5 13,5 48,5 48,5 49,1 49,1 34,7 34,7 9 13,2 13,2 48,7 48,7 49,6 49,6 35,0 35,0 10 (= p) 13,5 13,5 48,6 48,6 49,4 49,4 34,6 34,6 Mean at level (j) 13,2 48,9 49,3 35,0 NOTE Stirred settling apparatuses used for tests were of the standard Type 305 produced by Triton Electronics, Dunmow,
49、Essex (UK). EN 14702-2:2006 (E) 11 Table B.2 Stirred sludge volume index, ISSVOperator number (i) Level (j) Sample 1 Level Sample 2 Level Sample 3 Level Sample 4 (= q) values (yijk) ml/g mean (ij) ml/g values (yijk) ml/g mean (ij) ml/g values (yijk) ml/g mean (ij) ml/g values (yijk) ml/g mean (ij) ml/g 1 95,94 95,94 44,44 44,44 27,21 27,21 94,41 94,41 2 95,94 95,94 44,35 44,35 27,16 27,16 3 95,94 95,94 44,35 44,35 27,21 27,21 92,54 92,54 4 95,94 95,94 44,35 44,35 27,05 27,05 5 97,42
