ISO 9408:1999 PDF

Scope: This International Standard specifies a method, by determination of the oxygen demand in a closed respirometer, for the evaluation in aqueous medium of the ultimate biodegradability of organic compounds and waste waters at a given concentration by aerobic microorganisms. The method applies to organic compounds which a) are water-soluble under the conditions of the test; b) are poorly water-soluble under the conditions of the test, in which case special measures may be necessary to achieve good dispersion of the compound (see for example, ISO 10634); c) do not reach and react with the CO2 absorbent; d) are volatile, provided that a suitable respirometer or suitable conditions (e.g. a smaller ratio of volume head space to volume liquid medium) are used; e) are not inhibitory to the test microorganisms at the concentration chosen for the test. The presence of inhibitory effects can be determined as specified in 7.3, or by using any other method for determining the inhibitory effect of a compound on bacteria (see, for example, ISO 8192). NOTE The conditions described in this International Standard do not always correspond to the optimal conditions for allowing the maximum degree of biodegradation to occur. For alternative biodegradation methods, see ISO 15462.

ISO 9408:1999 history

1999 ISO 9408:1999 Water quality - Evaluation of ultimate aerobic biodegradability of organic compounds in aqueous medium by determination of oxygen demand in a closed respirometer
1992 ISO 9408:1991/Cor 1:1992 Water quality — Evaluation in an aqueous medium of the "ultimate" aerobic biodegradability of organic compounds — Method by determining the oxygen demand in a closed respirometer — Technical Corrigendum 1
1991 ISO 9408:1991 Water quality; evaluation in an aqueous medium of the "ultimate" aerobic biodegradability of organic compounds; method by determining the oxygen demand in a closed respirometer