1、BRITISH STANDARD BS EN ISO 11734:1999 BS 6068-5.21: 1996 Incorporating Amendment No.1 to BS 6068-5.21:1996 (renumbers the BS as BS EN ISO 11734:1999) Water quality Evaluation of the “ultimate” anaerobic biodegradability of organic compounds in digested sludge Method by measurement of the biogas prod
2、uction The European Standard EN ISO 11734:1998 has the status of a British Standard ICS 07.100.20BSEN ISO 11734:1999 This British Standard, having been prepared under the directionof the Health and Environment Sector Board, waspublished under the authorityof the Standards Boardand comes into effect
3、on 15 July 1996 BSI 06-1999 The following BSI references relate to the work on this standard: Committee reference EH/3/5 Draft for comment 94/502110 DC ISBN 0 580 25945 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee EH
4、/3, Water quality, to Subcommittee EH/3/5, Biological methods, upon which the following bodies were represented: BLWA Ltd. (The Association of the Laboratory Supply Industry) Department of Economic Development (Northern Ireland) Department of Health Department of the Environment (Her Majestys Inspec
5、torate of Pollution) Department of the Environment (Water Directorate) Freshwater Biological Association Institution of Water and Environmental Management Ministry of Agriculture, Fisheries and Food National Rivers Authority Royal Society of Chemistry Scottish Natural Heritage Soap and Detergent Ind
6、ustry Association Water Research Centre Amendments issued since publication Amd. No. Date Comments 10321 January 1999 Indicated by a sideline in the margin BSEN ISO 11734:1999 BSI 06-1999 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 1 Scope 3 2 Normative
7、references 3 3 Definitions 3 4 Principle 4 5 Test environment 4 6 Reagents 4 7 Apparatus 5 8 Procedure 5 9 Calculation and expression of results 7 10 Validity of results 8 11 Test report 8 Annex A (informative) Example of an apparatus to measure biogas production by gas pressure 10 Annex B (informat
8、ive) Example of a degradation curve (cumulative net pressure increase) 11 Annex C (informative) Examples of data sheets for the anaerobic biodegradation test 12 Annex D (informative) Bibliography 14 Annex ZA (normative) Normative references to international publications with their relevant European
9、publications 15 List of references Inside back coverBSEN ISO 11734:1999 ii BSI 06-1999 National foreword This British Standard is the English language version of EN ISO 11734:1998. It retains a dual identifier as BS6068-5.21:1996. It is identical with ISO11734:1995 published by the International Org
10、anization for Standardization (ISO). The international standard was prepared by ISO Technical Committee 147, Water quality, with the active participation and approval of the UK. BS6068 is being published in a series of Parts subdivided into Sections that will generally correspond to particular inter
11、national standards. Sections are being, or will be, published in Parts 1 to 7, which, together with Part 0, are listed below: Part 0: Introduction; Part 1: Glossary; Part 2: Physical, chemical and biochemical methods; Part 3: Radiological methods; Part 4: Microbiological methods; Part 5: Biological
12、methods; Part 6: Sampling; Part 7: Precision and accuracy. NOTEThe tests described in this Section of BS 6068 should only be carried out by suitably qualified persons with an appropriate level of biological expertise. Standard biological procedures should be followed throughout. Textual errors. When
13、 adopting the text of the international standard, the textual errors listed below were discovered. They have been marked in the text and have been reported to ISO in a proposal to amend the text of the international standard. In 6.7, line 4, after “(e.g.” insert “producing about”. In 8.1, in line 5
14、of the last paragraph delete “other ingredients” and substitute “sludge inoculum (6.7)”. In 9.1, in both definitions of symbol n after “gas” insert “in the given volume”. NOTETypographical errors. In Annex B, The title should read “cumulative” and not “cumulated”. Cross references. The Technical Com
15、mittee has reviewed the provisions of ISO10634:1995 and of the draft of ISO/DIS11923, to which normative reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. A British Standard does not purport to include all the necessary provisions of a
16、 contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theENISO title page, pages
17、 2 to 16, an inside back cover and a back cover, This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on theinside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 11734 July 1998 ICS 13.060.40
18、 Descriptors: Water, quality, sewage, sewage treatment sludges, organic compounds, tests, water tests, determination, biodegradability English version Water quality Evaluation of the “ultimate” anaerobic biodegradability of organic compounds in digested sludge Method by measurement of the biogas pro
19、duction (ISO 11734:1995) Qualit de leau Evaluation de la biodgradabilit anarobie “ultime” des composs organiques dans les boues de digesteurs Mthode par mesurage de la production de biogaz (ISO 11734:1995) Wasserbeschaffenheit Bestimmung der vollstndigen anaeroben biologischen Abbaubarkeit organisch
20、er Verbindungen im Faulschlamm Verfahren durch Messung der Biogasproduktion (ISO 11734:1995) This European Standard was approved by CEN on21June 1998. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status
21、 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 Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A ver
22、sion in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, CzechRepublic, Denmark, Finland, Fran
23、ce, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 19
24、98 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 11734:1998 EENISO 11734:1998 BSI 06-1999 2 Foreword The text of the International Standard from Technical Committee ISO/TC147, Water quality, of the International Organization
25、for Standardization (ISO) has been taken over as a European Standard by Technical Committee CEN/TC230, Water analysis, the Secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at th
26、e latest by January1999, and conflicting national standards shall be withdrawn at the latest by January1999. According to CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, CzechRepublic,
27、Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the UnitedKingdom. Endorsement notice The text of the International Standard ISO11734:1995 has been approved by CEN as a European Standard without any modific
28、ation. NOTENormative references to International Standards are listed in Annex ZA (normative).BSEN ISO11734:1999 BSI 06-1999 3 WARNING Sewage sludges may contain potentially pathogenic organisms. Therefore appropriate precautions must be taken when handling such sludges. Digesting sewage sludge prod
29、uces flammable gases which present fire and explosion risks. Care must be taken when transporting and storing quantities of digesting sludge. Toxic test chemicals and those whose properties are not known must be handled with care. The pressure meter and microsyringes must be handled carefully to avo
30、id injuries caused by needles. Contaminated syringe needles must be disposed of in a safe manner. 1 Scope This International Standard specifies a screening method for the evaluation of the biodegradability of organic compounds at a given concentration by anaerobic microorganisms. The conditions desc
31、ribed in this test do not necessarily correspond to the optimal conditions allowing the maximum value of biodegradation to occur, since a dilute sludge is used with a relatively high concentration of test chemical. The test allows exposure of sludge to the chemical for a period of up to 60 d, which
32、is longer than the normal sludge retention time (25d to30 d) in anaerobic digesters, though digesters at industrial sites can have much longer retention times. The method applies to organic compounds with a known carbon content and which are soluble in water; poorly soluble in water, provided that a
33、 method of exact dosing is applicable; not inhibitory to the test microorganisms at the concentration chosen for the test; inhibitory effects can be determined in separate tests or by an additional inhibition assay. For volatile substances a case by case decision is necessary. Some can be tested if
34、handled with special care, for example no release of gas during the test. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All
35、standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
36、 ISO 10634:1995, Water quality Guidance for the preparation and treatment of poorly water-soluble organic compounds for the subsequent evaluation of their biodegradability in an aqueous medium. ISO 11923:, Water quality Determination of suspended solids by filtration through glass-fibre filters 1) .
37、 3 Definitions For the purposes of this International Standard, the following definitions apply. 3.1 ultimate anaerobic biodegradation the level of degradation achieved when a test compound is utilized by anaerobic microorganisms resulting in the production of carbon dioxide, methane, mineral salts
38、and new microbial cellular constituents (biomass) 3.2 primary anaerobic biodegradation the level of degradation achieved when a test compound undergoes any structural change, other than complete mineralization, as a result of anaerobic microbial action 3.3 digested sludge a mixture of the settled ph
39、ases of sewage and activated sludge, which have been incubated in an anaerobic digester at about 35 C to reduce biomass and odour problems and to improve the dewaterability of the sludge. Digested sludge consists of an association of anaerobic fermentative and methanogenic bacteria producing carbon
40、dioxide and methane 3.4 concentration of total solids the amount of solids obtained by drying a known volume of sludge under specified conditions at about105 C to constant mass 1) To be published.BSEN ISO 11734:1999 4 BSI 06-1999 4 Principle Washed digested sludge, containing very low amounts of ino
41、rganic carbon (IC), is diluted to total solids concentration of 1 g/l to 3 g/l and incubated at35 C 2 C in sealed vessels with a test chemical at an organic carbon (OC) concentration of 20 mg/l to 100mg/l for up to about60 d. The increase in headspace pressure in the test vessels resulting from the
42、production of carbon dioxide (CO 2 ) and methane (CH 4 ) is measured. A considerable amount of carbon dioxide will be dissolved in water or transformed to hydrogen carbonate or carbonate under the conditions of the test. This inorganic carbon (IC) is measured at the end of the test. The amount of mi
43、crobiologically produced carbon is calculated from the net gas production and the net IC formation in excess over blank values. The percentage biodegradation is calculated from the total IC formed and the measured or calculated amount of carbon added as test compound. The course of biodegradation ca
44、n be followed by taking intermediate measurements of gas production only As additional information, the primary biodegradation can be determined by specific analyses at the beginning and end of the test. 5 Test environment Incubation shall take place in sealed vessels at a constant temperature of 35
45、 C 2 C, a normal temperature for an anaerobic digester, in the absence of oxygen, initially in an atmosphere of pure nitrogen. 6 Reagents 6.1 Distilled or deionized water, containing less than2 mg/l DOC. 6.2 Test medium 6.2.1 Medium Use only reagents of recognized analytical grade. Prepare the dilut
46、ion medium to contain the following constituents at the stated amounts: To achieve anoxic conditions, sparge the medium with nitrogen for about20min immediately before use to remove oxygen. Adjust the pH of the medium with dilute mineral acid or alkali, if necessary, to 7 0,2. NOTE 1Freshly supplied
47、 sodium sulfide should be used or it should be washed and dried before use, to ensure sufficient reductive capacity. 6.2.2 Stock solution of trace elements (optional) It is recommended to supply the test medium with the following trace elements to improve anaerobic degradation processes, especially
48、if low inoculum concentrations are used. 6.3 Test compound Add the test compound as a stock solution, supension, emulsion, or directly as solid or liquid to give a test concentration of100mg/l organic carbon. If stock solutions are used, prepare a suitable solution with water (6.1) of such strength
49、that the volume added is less than 5 % of the total volume of reaction mixture. For test compounds which are insufficiently soluble in water, see ISO10634, but do not use an organic solvent known to inhibit methane production such as chloroform or carbon tetrachloride. NOTE 2If solvents are used, a control with the solvent only is recommended. Anhydrous potassium dihydrogenphosphate (KH 2 PO 4 ) 0,27 g Disodium hydrogenphosphate dodecahydrate (Na 2 HPO 4 12H 2 O) 1,12 g Ammonium chloride (NH 4 Cl) 0,53
