1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 14701-4:2010Characterization of sludges Filtration propertiesPart 4: Determination of the drainability offlocculated sludgesBS EN 14701-4:2010 BRITISH STANDARDNational fore
2、wordThis British Standard is the UK implementation of EN 14701-4:2010.BSI, as a member of CEN, is obliged to publish EN 14701-4:2010as a British standard. However, attention is drawn to the factthat during the development of this European Standard, the UKcommittee voted consistently against this wor
3、k item and finallyagainst its approval as a European Standard. It submitted a negativevote because it considered that determining the drainability offlocculated sludges is at best an operational control tool and as suchthere is no necessity for comparing data between laboratories.The UK participatio
4、n in its preparation was entrusted to TechnicalCommittee EH/5, Sludge characterization.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for it
5、s correctapplication. BSI 2010ISBN 978 0 580 60027 2ICS 13.030.20Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 August 2010.Amendments issued since publication
6、Date Text affectedBS EN 14701-4:2010EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 14701-4 January 2010 ICS 13.030.20 English Version Characterization of sludges - Filtration properties - Part 4: Determination of the drainability of flocculated sludges Caractrisation des boues - Proprits de fi
7、ltration - Partie 4: Dtermination de laptitude lgouttage des boues flocules Charakterisierung von Schlmmen - Filtrationseigenschaften - Teil 4: Bestimmung der Entwsserbarkeit geflockter Schlmme This European Standard was approved by CEN on 28 November 2009. CEN members are bound to comply with the C
8、EN/CENELEC Internal Regulations which stipulate the conditions for giving this 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 Management Centre or
9、 to any CEN member. This European Standard exists 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 Management Centre has the same status as the official ver
10、sions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, S
11、lovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CE
12、N national Members. Ref. No. EN 14701-4:2010: EBS EN 14701-4:2010EN 14701-4:2010 (E) 2 Contents Page Foreword . 3Introduction . 41 Scope 52 Normative references 53 Terms and definitions . 54 Sludge conditioning 55 Principle . 66 Apparatus . 67 Procedure . 68 Expression of results 79 Test report 710
13、Precision 8Annex A (informative) Typical gravity drainage cell . 9Annex B (informative) Quantity of sludge in a gravity belt filtration . 10Annex C (informative) Results of validation trials . 11Bibliography 15BS EN 14701-4:2010EN 14701-4:2010 (E) 3 Foreword This document (EN 14701-4:2010) has been
14、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 status of a national standard, either by publication of an identical text or by endorsement, at the latest by July 2010, and conflicting nati
15、onal standards shall be withdrawn at the latest by July 2010. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. EN 14701, Characterisati
16、on 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 According to the CEN/CENELEC Internal Regulations, the national standards organizatio
17、ns of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
18、 Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 14701-4:2010EN 14701-4:2010 (E) 4 Introduction The determination of drainability of flocculated sludges is an important parameter for evaluating their suitability to be thickened by means of a draining process. It
19、 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
20、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
21、solids remaining in the filtrate and the best flocculant and its optimum dose in the case of comparative tests. BS EN 14701-4:2010EN 14701-4:2010 (E) 5 1 Scope This European Standard specifies a method for the determination of drainability of flocculated sludges. It is applicable to sludge and sludg
22、e 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 su
23、spensions 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) applie
24、s. EN 872, Water quality Determination of suspended solids Method by filtration through glass fibre filters 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, Cha
25、racterization of sludges Laboratory chemical conditioning procedure 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 drainability ability of treated sludge to separate from sludge liquor by gravity filtration 3.2
26、 flocculation coagulation by means of inorganic or organic flocculants (polyelectrolytes) 4 Sludge conditioning For flocculation, the sludge shall be sampled already flocculated or mixed with flocculant in repeatable and quantified conditions according to CEN/TR 14742 for a laboratory preparation. B
27、S EN 14701-4:2010EN 14701-4:2010 (E) 6 5 Principle A given volume of flocculated sludge is poured in a filter cell equipped with a known filtering medium, 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
28、the undissolved solids remaining in the filtrate are measured. 6 Apparatus Ordinary laboratory apparatus and the following (see informative Annex A): 6.1 Transparent tube (e.g. glass, polyethylene) of 150 mm diameter and of about 200 mm height, supported by a system composed of a filtering medium ti
29、ghtened in a device equipped with an appropriate sealing joint. 6.2 Filtering medium whose characteristics shall be the same as 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.
30、 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 shall 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
31、filtering medium. 6.7 Apparatus for the determination of suspended solids in the filtrate. NOTE 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
32、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 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 mediu
33、m. 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 E
34、N 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 twice if repeatability measurements are needed. BS EN 14701-4:2010EN 14701-4:2010 (E) 7 8 Expression of results Plot adimensional mass versus time: ()tfMM=0where M is the
35、 mass of filtrate, in grams (g); M0is the initial mass of sludge, in grams (g); t is the time of experiment, in seconds (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 v
36、olume 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 of the drainage process are those for which the drainage is the fast
37、est 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 Test report The test report shall contain at least the following information: a) Reference to this doc
38、ument; b) Identification of the sludge (origin, type, identification, concentration, method of sampling and storage); c) Identification of the flocculation conditions and preparation; d) Characteristics of sludge and filtering medium (initial mass and water content of sludge, reference and supplier
39、of the filtering medium); e) Adimensional mass recovered versus time with at least the volume of filtrate collected at t = 30 s, at t = 90 s and at the end of the test; f) Time, in seconds (s), corresponding to the collection of 50 % of the initial water content of the sludge; g) Dry mass of the sus
40、pended solids per unit volume of filtrate (in milligrams per litre (mg/l); h) Dryness (mass fraction in percent (%) of sludge cake retained on the filtering medium; i) Any detail not specified in this document or which are optional and any other factor which may have affected the results. BS EN 1470
41、1-4:2010EN 14701-4:2010 (E) 8 10 Precision Full results of validation trials, which three types of sludge (i.e. digested sewage sludge, raw sewage sludge, and waterworks sludge) were used for, are reported in informative Annex C . All sludge types considered, average values of relative repeatability
42、 standard deviation were 4,6 % for adimensional mass of filtrate at 30 s, 3,5 % for adimensional mass of filtrate at 90 s, 2,0 % for adimensional mass of filtrate at test end, 20 % for the time to collect 5/10 of sludge water content, 1,8 % for dryness of cake, and 14 % for suspended matter in the f
43、iltrate. Minimum value was 1,4 % for dryness of cake of both digested sewage sludge and waterworks sludge, while maximum one was 22 % for the time to collect 5/10 of water content of digested sewage sludge. All sludge types considered, average values of relative reproducibility standard deviation we
44、re 4,3 % for adimensional mass of filtrate at 30 s, 3,2 % for adimensional mass of filtrate at 90 s, 2,6 % for adimensional mass of filtrate at test end, 20 % for the time to collect 5/10 of sludge water content, 2,3 % for dryness of cake, and 31 % for suspended matter in the filtrate. Minimum value
45、 was 1,0 % for adimensional mass of filtrate at test end of digested sewage sludge, while maximum one was 37 % for suspended matter in the filtrate of raw sewage sludge. At least the precision data given as averages should be reached in the analysis of sludges. BS EN 14701-4:2010EN 14701-4:2010 (E)
46、9 Annex A (informative) Typical gravity drainage cell Key 1 Cylindrical tube in transparent material 2 Filtering medium 3 Tightening device with sealing joint 4 Filtrate draining device 5 Filtrate collector (beaker) 6 Weighing balance 7 Computer Figure A.1 Gravity drainage cell BS EN 14701-4:2010EN
47、14701-4:2010 (E) 10 Annex B (informative) Quantity of sludge in a gravity belt filtration The ratio of the mass of sludge to be deposited per unit surface area of the filter cloth AM0can be calculated from the characteristics of the industrial equipment, using Equation (A.1): +=bpb0SLQQAM(A.1) where
48、 M0is the mass of sludge poured in the cell, in kilograms (kg); A is the cell area, in square metres (m2); Qbis the sludge flow rate feeding the industrial equipment, in kilograms per second (kg/s); Qpis the polymer flow rate feeding the industrial equipment, in kilograms per second (kg/s); L is the
49、 belt width, in metres (m); Sbis the belt velocity, in metres per second (m/s). If the characteristics of the industrial equipment are unknown, the quantity of sludge poured shall be able to build a cake whose height ranges from 1 cm to 3 cm. BS EN 14701-4:2010EN 14701-4:2010 (E) 11 Annex C (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 duri
