BS ISO 18830-2016 Plastics Determination of aerobic biodegradation of non-floating plastic materials in a seawater sandy sediment interface Method by measuring the oxygen demand in.pdf

1、BS ISO 18830:2016Plastics Determination ofaerobic biodegradation of non-floating plastic materials ina seawater/sandy sedimentinterface Method bymeasuring the oxygen demandin closed respirometerBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS ISO 18830:2016 BRITISH

2、 STANDARDNational forewordThis British Standard is the UK implementation of ISO 18830:2016.The UK participation in its preparation was entrusted to TechnicalCommittee PRI/21, Testing of plastics.A list of organizations represented on this committee can beobtained on request to its secretary.This pub

3、lication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 84563 5ICS 83.080.01Compliance with a British Standard cannot confer immunity

4、 fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 September 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 18830:2016 ISO 2016Plastics Determination of aerobic biodegradation of no

5、n-floating plastic materials in a seawater/sandy sediment interface Method by measuring the oxygen demand in closed respirometerPlastiques Dtermination de la biodgradation arobie des matires plastiques immerges linterface eau de mer/sdiments sableux Mthode par mesurage de la demande en oxygne dans u

6、n respiromtre fermINTERNATIONAL STANDARDISO18830First edition2016-08-15Reference numberISO 18830:2016(E)BS ISO 18830:2016ISO 18830:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this pub

7、lication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the cou

8、ntry of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 18830:2016ISO 18830:2016(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Princ

9、iple 25 Test environment . 26 Reagents 27 Apparatus . 38 Procedure. 48.1 Test material . 48.2 Reference material . 48.3 Preparation of the sediment 48.4 Test setup . 48.5 Pre-conditioning phase 58.6 Start of the test 58.7 End of the test 59 Calculation and expression of results . 69.1 Calculation 69

10、.2 Visual inspection . 69.3 Expression and interpretation of results . 610 Validity of results . 711 Test report . 7Annex A (informative) Example of respirometric system based on pressure measurement 8Bibliography 9 ISO 2016 All rights reserved iiiContents PageBS ISO 18830:2016ISO 18830:2016(E)Forew

11、ordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technic

12、al committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of el

13、ectrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was

14、 drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such paten

15、t rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not co

16、nstitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/i

17、so/foreword.html.The committee responsible for this document is ISO/TC 61, Plastics, Subcommittee SC 5, Physical-chemical properties.iv ISO 2016 All rights reservedBS ISO 18830:2016ISO 18830:2016(E)IntroductionProducts made with biodegradable plastics are designed to be recovered by means of organic

18、 recycling in composting plants or in anaerobic digesters. The uncontrolled dispersion of biodegradable plastics in natural environments is not desirable. The biodegradability of products cannot be considered as an excuse to spread wastes that should be recovered and recycled. However, test methods

19、to measure rate and level of biodegradation in natural environments (such as soil or the marine environment) are of interest in order to better characterize the behaviour of plastics in these very particular environments. As a matter of fact, some plastics are used in products that are applied in th

20、e sea (e.g. fishing gear) and sometimes they can get lost or put willingly in marine environment. The characterization of biodegradable plastic materials can be enlarged by applying specific test methods that enable the quantitative assessment of biodegradation of plastics exposed to marine sediment

21、 and seawater.Plastic products are directly littered or arrive with fresh waters in the pelagic zone (free water). From there, and depending on density, tides, currents, and marine foiling may sink to the sublittoral, and reach the seafloor surface. Many biodegradable plastics have a density higher

22、than 1 and therefore tend to sink. The sediment passes from aerobic to anoxic and finally anaerobic conditions going from the surface (the interface with seawater) into deeper layers, displaying a very steep oxygen gradient. ISO 2016 All rights reserved vBS ISO 18830:2016BS ISO 18830:2016Plastics De

23、termination of aerobic biodegradation of non-floating plastic materials in a seawater/sandy sediment interface Method by measuring the oxygen demand in closed respirometer1 ScopeThis International Standard specifies a test method to determine the degree and rate of aerobic biodegradation of plastic

24、materials when settled on marine sandy sediment at the interface between seawater and the seafloor, by measuring the oxygen demand in a closed respirometer.Measurement of aerobic biodegradation can also be obtained by monitoring the carbon dioxide evolution. This is not in the scope of this Internat

25、ional Standard but of ISO 19679.This test method is a simulation under laboratory conditions of the habitat found in different seawater/sediment-areas in the sea, e.g. in a benthic zone where sunlight reaches the ocean floor (photic zone) that, in marine science, is called sublittoral zoneThe determ

26、ination of biodegradation of plastic materials buried in marine sediment is outside the scope of this International Standard.The conditions described in this International Standard may not always correspond to the optimum conditions for the maximum degree of biodegradation to occur.2 Normative refer

27、encesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO

28、 14851:1999, Determination of the ultimate aerobic biodegradability of plastic materials in an aqueous medium Method by measuring the oxygen demand in a closed respirometerISO 8245, Water quality Guidelines for the determination of total organic carbon (TOC) and dissolved organic carbon (DOC)3 Terms

29、 and definitionsFor the purposes of this document, the following terms and definitions apply.3.1biochemical oxygen demandBODmass concentration of the dissolved oxygen consumed under specified conditions by the aerobic biological oxidation of a chemical compound or organic matter in waterNote 1 to en

30、try: It is expressed as milligrams of oxygen uptake per milligram or gram of test compound.INTERNATIONAL STANDARD ISO 18830:2016(E) ISO 2016 All rights reserved 1BS ISO 18830:2016ISO 18830:2016(E)3.2theoretical oxygen demandThODtheoretical maximum amount of oxygen required to oxidize a chemical comp

31、ound completely, calculated from the molecular formulaNote 1 to entry: It is expressed as milligrams of oxygen uptake per milligram or gram of test compound.3.3total organic carbonTOCall the carbon present in organic matter which is dissolved or suspended in water3.4pre-conditioning phasepre-incubat

32、ion of an inoculum under the conditions of the subsequent test in the absence of test material, with the aim to consume potential organic matter present in excess that could disturb biodegradation measurement and to improve the acclimatization of the microorganisms to the test conditions4 PrincipleT

33、his test method is based on the determination of biological oxygen demand (BOD) and derives from ISO 14851. The testing medium is based on a solid phase and a liquid phase. The solid phase is sandy marine sediment laid in the bottom of a closed flask; the liquid phase is a column of natural or artif

34、icial sea water, poured on the sediment. The test material is preferably in the form of a film to be laid down on top of the sediment, at the interface between the solid phase and the liquid phase. This is a simulation of an object that has sunk and finally reached the sea floor. The system is conta

35、ined in a closed flask, in a respirometer. The carbon dioxide evolved is absorbed in a suitable absorber in the headspace of the flasks. The consumption of oxygen (BOD) is determined, for example, by measuring the amount of oxygen required to maintain a constant volume of gas in the respirometer fla

36、sks, or by measuring the change in volume or pressure (or a combination of the two) either automatically or manually.The level of biodegradation is determined by comparing the BOD with the theoretical amount (ThOD) and expressed in percentage. The influence of possible nitrification processes on the

37、 BOD shall be considered. The test result is the maximum level of biodegradation determined from the plateau phase of the biodegradation curve.The details of interlaboratory testing based on the test method specified in this International Standard are available in Reference 4.5 Test environmentIncub

38、ation shall take place in the dark or diffused light in an enclosure which is free from vapours inhibitory to microorganisms and which is maintained at a constant temperature, preferably between 15 C to 25 C, but not exceeding 28 C, to an accuracy of 2 C. Any change in temperature shall be justified

39、 and clearly indicated in the test report.NOTE Test results are obtained for temperature that may be different from real conditions in marine environment.6 Reagents6.1 Distilled or deionized water, free of toxic substances (copper in particular) and containing less than 2 mg/l of DOC.2 ISO 2016 All

40、rights reservedBS ISO 18830:2016ISO 18830:2016(E)6.2 Artificial seawaterDissolve:Sodium chloride (NaCl) 22 gMagnesium chloride hexahydrate (MgCl2 6 H2O) 9,7 gSodium sulfate (Na2SO4) 3,7 gCalcium chloride (CaCl2) 1 gPotassium chloride (KCl) 0,65 gSodium hydrogen carbonate (NaHCO3) 0,20 gin water (6.1

41、) and make up to 1 000 ml.6.3 Natural seawater/sedimentTake a sample of a sandy sediment and seawater with a shovel beneath the low-water line into a bucket. Transfer the wet sediment together with seawater into sealed containers for transport and fast deliver it to the laboratory. After delivery, c

42、onserve the sediment at low temperature (approximately 4 C) until use. The seawater/sediment sample should be preferably used within 4 weeks after sampling. Record storage time and conditions.NOTE Seawater and sediment can also be sampled from large, well-running public marine aquaria.Measure the TO

43、C, pH and nitrogen content of the sediment and of the natural seawater if used instead of artificial seawater. The carbon content of sediment should be in the range of 0,1 % to 2 %.A preliminary oxidation can be applied to the sediment in order to decrease the organic matter content and the backgrou

44、nd respiration. Sediment and seawater are fluxed with air and gently stirred (max. 20 r/min to 30 r/min) in a large container for the desired period of time. Report this pre-treatment procedure in the test report.7 Apparatus7.1 Closed respirometer, including test vessels (glass flasks) and all other

45、 necessary equipment, shall be located in a constant-temperature room or in a thermostat apparatus (e.g. water-bath). For an example, see Annex A or ISO 14851:1999, Annex C. Stirring can be applied on seawater on condition that it does not disturb the sediment/seawater interface. An example of a sti

46、rred apparatus is given in OECD TG 308, Annex 4.3NOTE Any respirometer able to determine with sufficient accuracy the biochemical oxygen demand is suitable, preferably an apparatus which measures and replaces automatically and continuously the oxygen consumed so that no oxygen deficiency and no inhi

47、bition of the microbial activity occurs during the degradation process. Analytical equipment to measure total organic carbon (TOC) and dissolved organic carbon (DOC) is given in ISO 8245.7.2 Analytical equipment for measuring nitrate and nitrite concentrationsA qualitative test is recommended first

48、to decide if any nitrification has occurred. If there is evidence of nitrate/nitrite in the medium, a quantitative determination using a suitable method (for example ion chromatography) is required.7.3 Analytical balance (usual laboratory equipment)Analytical balance shall have a sensitivity of at l

49、east 0,1 mg. ISO 2016 All rights reserved 3BS ISO 18830:2016ISO 18830:2016(E)7.4 pH meter (usual laboratory equipment)8 Procedure8.1 Test materialThe test material should be in film or sheet form. Cut samples of the test material in the shape of a disk. Disks shall have a smaller diameter than the glass flasks, so that the disks can be easily laid on the bottom of the glass flask.The sample shall be of known mass and contain sufficient carbon to yield a BOD that can be adequately measured by the respirometer used.Use