ISO INTERNATIONAL STANDARD 11734 First edition 1995-12-15 Water quality Evaluation of the "ultimate" anaerobic biodegradability of organic compounds in digested sludge Method by measurement of the biogas production Qualite de I'eau -- Evaluation de la biodégradabilite anaérobie 《ultime des composés organiques dans les boues de digesteurs - Methode par mesurage de la production de biogaz Iso Reference number ISO11734:1995(E) Copyright International Organization for Standardization nitted without license from IHS Not for Resale ISO 11734:1995(E) Foreword IsO (the International Organization for Standardization) is a worldwide technical committees. Each member body interested in a subject for which a technical 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 electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International a vote. ISO/TC 147, Water quality, Subcommittee SC 5, Biological methods. Annexes A, B, C and D of this International Standard are for information only. ISO 1995 All rights reserved. Unless otherwise specified, 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 Geneve 20 · Switzerland Printed in Switzerland ii No reproductic on or networking permitted without license from IHS Not for Resale ISO 11734:1995(E) INTERNATIONAL STANDARD ISO Water quality - Evaluation of the "ultimate" anaerobic biodegradability of organic compounds in digested sludge -- Method by measurement of the biogas production WARNING - Sewage sludges may contain potentially pathogenic organisms. Therefore appropriate precautions must be taken when handling such sludges. Digesting sewage sludge produces 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 avoid injuries caused by needles. Contaminated syringe needles must be disposed of in a safe manner. Scope fects can be determined in separate tests or by an additional inhibition assay. This International Standard specifies a screening For volatile substances a case by case decision is methodforthe evaluation of the biodegradabilityof necessary. Some can be tested if handied with special organic compounds at a given concentration by care, for example no release of gas during the test anaerobic microorganisms. The conditions described inthistestdonotnecessarilycorrespondtotheopti mal conditions allowing the maximum value of bio- degradation to occur, since a dilute sludge is used with a relatively high concentration of test chemical. Normative references The test aliows exposure of sludge to the chemical for a period of up to 60 d, which is longer than the normal The following standards contain provisions which, siudge retention time (25 d to 30 d) in anaerobic throughreferencein thistext,constitute provisions digesters,thoughdigestersatindustrialsitescanhave of this International Standard. At the time of publica- much longer retention times. tion,theeditionsindicatedwerevalid.All standards aresubjecttorevision,andpartiestoagreements The method applies to organic compounds with a based on this internationai Standard are encouraged knowncarboncontentandwhichare to investigate the possibility of applying the most re- cent editions of the standards indicated below. soluble in water; Membe