SIST EN 29439:1997

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Wasserbeschaffenheit - Bewertung der vollständigen aeroben biologischen Abbaubarkeit organischer Stoffe im wäßrigen Medium - Verfahren mittels Analyse des feigesetzten Kohlendioxids (ISO 9439:1990)Qualité de l'eau - Evaluation, en milieu aqueux, de la biodégradabilité aérobie "ultime" des composés organiques - Méthode par dosage du dioxyde de carbone dégagé (ISO 9439:1990)Water quality - Evaluation in an aqueous medium of the "ultimate" aerobic biodegradability of organic compounds - Method by analysis of released carbon dioxide (ISO 9439:1990)13.060.70Preiskava bioloških lastnosti vodeExamination of biological properties of waterICS:Ta slovenski standard je istoveten z:EN 29439:1993SIST EN 29439:1997en01-avgust-1997SIST EN 29439:1997SLOVENSKI
STANDARD



SIST EN 29439:1997



SIST EN 29439:1997



SIST EN 29439:1997



INTER NATIONAL STANDARD IS0 9439 First edition 1990-1 2-01 Water quality - Evaluation in an aqueous medium of the “ultimate” aerobic biodegradability of organic compounds - Method by analysis of released carbon dioxide Qualité de l‘eau - Évaluation, en milieu aqueux, de la biodégradahilité aérobie “ultime” des composés organiques - Méthode par dosage du dioxyde de carbone dégagé Reference number IS0 9439: 1990( E) SIST EN 29439:1997



IS0 9439:1990(E) Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 technical committees. Each member body interested in a subject for which a technical committee has been established has the right io be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with ISO, also take pari in the work. IS0 collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an Inter- national Standard requires approval by at least 75% of the member bodies casting a vote. International Standard IS0 9439 was prepared by Technical Committee ISO/TC 147, Wafer quality. Annexes A, B and C of this International Standard are for information only. O IS0 1990 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case Postale 56 CH-1211 Genève 20 Switzerland Printed in Switzerland ii SIST EN 29439:1997



INTERNATIONAL STANDARD IS0 9439:1990(E) - - ~ ___ ____ Water quality - Evaluation in an aqueous medium of the ”ultimate” aerobic biodegradability of organic compounds - Method by analysis of released carbon dioxide 1 scope 0 This International Standard specifies a method, by analysis of released carbon dioxide, for the evalu- ation in an aqueous medium of the “ultimate” biodegradability of organic compounds at a given conce nt rat ion by a e robi c mi cro-org a n i s m s, The method applies to organic compounds which a re a) soluble in the test conditions; b) insoluble in the test conditions, in which case special measures may be necessary to achieve good dispersion of the compound; c) non-volatile or which have a negligible vapour pressure under the conditions of the test; d) not inhibitory to the test micro-organisms at the concentration chosen for the test. The presence of an inhibitory effect can be determined as specified in 8.3 , or by using any other method for determining the inhibitory effect of a compound on bacteria (see, for example, IS0 8192). 0 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publi- cation, the editions indicated were valid. All stan- dards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of ap- plying the most recent editions of the standards in- dicated below. Members of IEC and IS0 maintain registers of currently valid International Standards. IS0 7827:1984, Water quality - Evaluation in an aqueous medium of the “ultimate” aerobic biodegradability of organic compounds - Method by analysis of dissolved organic carbon (DOC). IS0 8192:1986, Water quality - Test for inhibition of oxygen consumption by activated sludge. 3 Definitions For the purposes of this International Standard, the following definitions apply. 3.1 ultimate biodegradation: The level of degrada- tion achieved when the test compound is totally uti- lized by micro-organisms resulting in the production of carbon dioxide, water, mineral salts and new microbial ce I I u I a r constituents (biom ass). 3.2 suspended solids (of an activated sludge): Sol- ids removed by filtration or centrifuging of a known volume of siiidge under specified conditions, and, for the purpose of this International Standard, drying at about 100 “C. 3.3 pre-exposure (or pre-adaptation): The pre- incubation of an inoculum in the presence of the test compound, with the aim of enhancing the ability of the inoculum to degrade the test compound. 3.4 pre-conditioning (or pre-acclimatization): The pre-incubation of an inoculum under the conditions of the test in the absence of the test compound, to improve the performance of the test. 4 Principle Determination of the biodegradation of organic compounds by aerobic micro-organisms, using a test medium. 1 SIST EN 29439:1997



IS0 9439:1990(E) The organic compound is the sole source of carbon and energy in the medium. The level of biodegradation is determined indirectly by meas- urement of the released carbon dioxide during the test time (generally 28 days). The concentration of the compounds used is such that the initial organic carbon content of the medium is normally between 10 mg/l and 40 mg/l. If required, more than 40 mg/l may be used to give additional information. For sufficiently water-soluble compounds, DOC re- moval at the end of the test may be determined. 5 Test environment Incubation shall take place in the dark or in diffused light, in an enclosure which is maintained at a con- stant temperature (within at least & 1 OC) between 20 "C and 25 "C and which is free from toxic va- pours. 6 Reagents Use only reagents of recognized analytical grade. 6.1 Distilled or de-ionized water. Containing less than 10 % of the initial DOC content introduced by the organic compound to be tested. 6.2 Test medium 6.2.1 Composition 6.2.1.1 Solution a). Anhydrous potassium 8,5 9 dihydrogenphosphate (KH,PO,) Anhydrous di pot as si u m hydrogenphosphate (K,HPO,) 21,75 g Disodium hydrogenphosphate dihydrate 33,4 g (Na,H P0,.2H20) Ammonium chloride (",CI ) 03 g Water (6.1) (quantity necessary to make up to) 1 O00 ml The pH of this solution should be about 7,4. 6.2.1.2 Solution b). Dissolve 22,5 g of magnesium sulphate heptahydrate (MgS0,.7H20) in 1 O00 ml of the water (6.1). 6.2.1.3 Solution e). Dissolve 27,5 g of anhydrous calcium chloride (CaCI,) or 36,4 g of calcium chloride dihydrate (CaCl2.2H,O) in 1 O00 ml of the water (6.1). 6.2.1.4 Solution d) Dissolve 0,25 g of iron(ll1) chloride hexahydrate (FeCI,.GH,O) in 1 O00 ml of the water (6.1). Prepare this solution just before use. NOTE 1 It is not necessary to prepare this solution just before use if a drop of concentrated hydrochloric acid (HCI) or 0,4 g/l of ethylenediamine-tetraacetic acid (EDTA) is added. 6.2.2 Preparation of the test medium. For 1 litre of test medium, add just before use to 800 ml of the water (6.1) - 10 ml of solution a); - and then 1 ml of each solution b), c) and d), (to avoid the formation of turbidity in the final me- dium). Make up to 1 O00 ml with the water (6.1). 7 Apparatus Ensure that all glassware is thoroughly cleaned and, in particular, free from organic or toxic matter. Usual laboratory equipment, and 7.1 lowing gas purge and magnetic stirring (see 8.3). Glass vessels, Erlenmeyer flasks or bottles al- 7.2 CO,-free air production system, capable of supplying each test flask at a flow rate between 50 ml/min and 100 ml/min, held constant within 10 Oh (see example of assembly in annex A). Check the absence of carbon dioxide in the air pro- duction system. 7.3 Apparatus for the determination of carbon di- oxide, carbon dioxide analyser or device for titrimetric determination afler complete absorption in a basic solution (see the principle of a test system with released carbon dioxide in annex A). 7.4 Device for filtration, with membrane filters of suitable porosity (nominal aperture diameter be- tween 0,2 pm and 0,45 pm) which adsorb organic compounds or release organic carbon to a minimum degree. 7.5 Instrument for the determination of dissolved organic carbon concentration 2 SIST EN 29439:1997



IS0 9439:1990(E) 7.6 Centrifuge 7.7 pH-meter. 8 Procedure 8.1 Preparation of the test solutions 8.1.1 Solution of the test compound Prepare a stock solution of the test compound in the test medium (6.2). Dilute a suitable amount of this solution in the previously aerated test medium (see 8.3 ) in order to obtain a final organic carbon con- centration of between 10 mg/l and 40 mg/l. NOTE 2 Compounds of low water solubility may be added directly, in solid or liquid form to the medium in the appropriate flask; an IS0 International Standard will be prepared for guidance. 8.1.2 Solution of the reference compound Prepare a stock solution of the reference compound (an organic compound of known biodegradability such as sodium acetate, sodium benzoate, aniline) in the test medium (6.2) in the same way as in 8.1.1, in order to obtain a final organic carbon con- centration of 20 mg/l. 8.1.3 Solution to check inhibition If necessary, prepare the solution containing, in the test medium (6.2), the test compound and the refer- ence compound in the respective concentrations used for the preparation of solutions in 8.1.1 and 8.1.2 . 8.2 Preparation of the inoculum Prepare the inoculum using the following sources or using a mixture of these sources to obtain a microbial population that offers sufficient biodegradation activity. Check this activity by means of the reference compound (8.1.2). The carbon dioxide production of the blank solution should be in the range of 30 mg/l to 40 mg/l but not 1) "Suitable" volume means greater than 70 mg/l. To reduce the influence of the blank, it may be helpful to precondition the sludge by aerating it up to one week before it is used [see clause 10, item b)]. The quantity of dissolved organic carbon provided by the inoculum shall be less than 10 of the initial concentration of organic carbon introduced by the test compound. NOTE 3 In certain circumstances, pre-exposed inocula may be used, provided that this is clearly stated in the test results (e.g. per cent biodegradation = x YO, using pre-exposed inocula) and the method of pre-exposure de- tailed in the test report. Pre-exposed inocula can be obtained from laboratory biodegradation tests conducted under a variety of condi- tions (e.g. Zahn-Wellens and SCAS tests) or from samples collected from locations where relevant environmental conditions exist (e.g. treatment plants dealing with similar compounds, contaminated areas, etc.). 8.2.1 Inoculum from a secondary effluent Take a sample of secondary effluent collected from a treatment plant dealing with predominantly do- mestic sewage. Keep this sample under aerobic conditions and use on the day of collection. From this sample, prepare an inoculum as follows: - let the sample of effluent settle for 1 h; - take a suitable volume') of the supernatant, to be used as inoculum for the test carried out that day. 8.2.2 Inoc
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