NEN-ISO 9888
Water quality - Evaluation of the aerobic biodegradability of organic compounds in an aqueous medium - Static test (Zahn-Wellens method)
| Organization: | NEN |
| Publication Date: | 1 April 1993 |
| Status: | inactive |
| ICS Code (Examination of biological properties of water): | 13.060.70 |
scope:
This standard specifies a method for the evaluation of the elimination and the "ultimate" biodegradability of organic compounds at a given concentration by aerobic micro-organisms. The conditions described in this standard normally correspond to optimal conditions for allowing the maximum value of biodegradation to occur with the chosen inoculum in the test time. The method applies to organic compounds which are a) soluble at the concetration used under the test conditions; b) non-volatile, or which have a negligible vapour pressure under the test conditions; c) not lost by foaming from the test solution; d) not inhibitory to the test micro-organisms at the concentration chosen for the test. Inhibitory effects can be determined by using a suitable test method (e.g. see ISO 8192). If the test compound is toxic, the test concentration has to lower or a pre-exposed inoculum can be used. The method can also be used to measure the elimination and biodegradation of organic compounds in waste water (also called "test compound" in the method).
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