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、g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58Licensed Copy: Wang Bin, na, Tue Aug 21 01:11:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSIBS EN 14702-2:2006This British Standard was published under the authority of the Standards Policy and
3、 Strategy Committee on 30 April 2007 BSI 2007ISBN 978 0 580 50511 9National forewordThis British 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 organiza
4、tions represented on EH/5 can be obtained on request to its secretary.The UK committee has 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
5、 British method was selected. The method has long been used as a valuable operational-control 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
6、properties do not change) to laboratories for international interlaboratory trials of the performance 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 doe
7、s not specify all such operational details, the performance data are not really applicable 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 provision
8、s of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments issued since publicationAmd. No. Date CommentsLicensed Copy: Wang Bin, na, Tue Aug 21 01:11:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEURO
9、PEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 14702-2March 2006ICS 13.030.20English VersionCharacterization of sludges - Settling properties - Part 2:Determination of thickenabilityCaractrisation des boues - Proprits de sdimentation -Partie 2: Dtermination de laptitude lpaississementCharakterisierun
10、g 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/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national
11、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 CEN member.This European Standard exists in three official versions (English, French, German). A version in any other
12、 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 members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France
13、,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 STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUN
14、GManagement 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 14702-2:2006: ELicensed Copy: Wang Bin, na, Tue Aug 21 01:11:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14702-2:2006 (E
15、) 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 determining the thickenability of
16、 sludges 8 Annex B (informative) Results of validation trials .9 Bibliography 12 Licensed Copy: Wang Bin, na, Tue Aug 21 01:11:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14702-2:2006 (E) 3 Foreword This document (EN 14702-2:2006) has been prepared by Technical Committee CEN/TC 308 “Characteriza
17、tion of sludges”, 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 September 2006, and conflicting national standards shall be withdrawn at the latest by
18、September 2006. Another part of this European Standard is: Part 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 t
19、o implement this European Standard: 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
20、 United Kingdom. Licensed Copy: Wang Bin, na, Tue Aug 21 01:11:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14702-2:2006 (E) 4 Introduction Determination of the thickenability, i.e. the further concentration of suspended (undissolved) sludge solids in settling under gravity, through the use of la
21、boratory mechanical assisted cylinders is negatively affected by bridging, wall effects and particle size effects. Ideally, this parameter should be measured in large-diameter columns having the same depth as the prototype thickener, but above effects can be satisfactory overcome by introducing a lo
22、w-speed stirrer in a cylinder; this also helps to reduce the effect of the shallow depth. Licensed Copy: Wang Bin, na, Tue Aug 21 01:11:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14702-2:2006 (E) 5 1 Scope This document specifies a method for the determination of the thickenability of sludge su
23、spensions. 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 91/271 EEC); water supply treatment plants. This method
24、 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 (
25、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 sludge solids to further concentrate in mechanical assis
26、ted 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 sludge, measured in a stirred cylinder 4 Principle The t
27、hickenability 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 properties vary with the solids concentration. Therefore, t
28、he comparison of these properties of sludge suspensions having different solids concentrations is allowed if a reference concentration is assumed; the Licensed Copy: Wang Bin, na, Tue Aug 21 01:11:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14702-2:2006 (E) 6 value of 3,5 g/l has been found to b
29、e the optimal one 1. Settling properties 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 betw
30、een the temperature of the sample and 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, diamete
31、r 10 cm, measuring height 50 cm, nominal 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 im
32、mediately poured into the graduated cylinder 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 obtaine
33、d through dilution by supernatant liquor 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
34、average of at least two measurements. 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 suspen
35、sion, in centimetres; 1 000 is a conversion 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 (infor
36、mative). Licensed Copy: Wang Bin, na, Tue Aug 21 01:11:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14702-2:2006 (E) 7 The reproducibility 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/th
37、ickened 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 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 identificatio
38、n of the sludge sample; c) details of sample preparation; e. g. dilution; d) results of the determination according to Clause 8; e) any details not specified in this document or which are optional and any other factor which may have affected the results. Licensed Copy: Wang Bin, na, Tue Aug 21 01:11
39、:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 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 graduated transparent cylinder, diameter 10 cm, measuring height 50 cm, equipped wi
40、th 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 second at a distance from the cylinder wall of about 2,5 cm, with a remaining distanc
41、e between them of about 5,0 cm. Licensed Copy: Wang Bin, na, Tue Aug 21 01:11:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 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 problem
42、s 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 “circ
43、ulation of 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
44、2004. Trials 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)
45、, University 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 r
46、esidue (%): 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 repeatab
47、ility standard 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
48、 the replicates; 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); Licensed Copy: Wang Bin, na, Tue Aug 21 01:11:12 GMT+00:00 2007, Uncontrolle
49、d Copy, (c) BSIEN 14702-2:2006 (E) 10 sris the repeatability standard deviation; sRis the reproducibility 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) 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
