AS 4351.3-1996

Sets out a method for the evaluation of the 'ready' biodegradability of organic compounds by aerobic microorganisms using a test medium. Measurement of the percentage consumption of oxygen within a closed flask at regular intervals allows evaluation of the biodegradability of the test compound. The method generally applies to compounds which are soluble in the test medium, do not reach or react with the CO(sub)2(/sub) absorbent, are volatile and not inhibitory to the test microorganisms at the concentration chosen for the test. Technically equivalent to ISO 9408:1991.

This Standard specifies a method, by determination of the oxygen demand in a closed respirometer, for the evaluation of the 'ready' biodegradability of organic compounds at a given concentration by aerobic microorganisms.The conditions described in this Standard do not always correspond to the optimal conditions which allow the maximum degree of biodegradation to occur.The method applies to organic compounds which-(a) are soluble in the test conditions;(b) are insoluble in the test conditions, in which case special measures may be necessary to achieve good dispersion of the compound;(c) do not reach or react with the CO2 absorbent;(d) are volatile, provided that a suitable respirometer is used; and(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 Clause 8.3, or by using any other method for determining the inhibitory effect of a compound on bacteria (e.g. ISO 8192).WARNING AND SAFETY PRECAUTIONS: ACTIVATED SLUDGE AND SEWAGE MAY CONTAIN POTENTIALLY PATHOGENIC ORGANISMS. THEREFORE, APPROPRIATE PRECAUTIONS SHOULD BE TAKEN WHEN HANDLING THEM. TOXIC TEST COMPOUNDS AND THOSE WHOSE PROPERTIES ARE UNKNOWN SHOULD BE HANDLED WITH CARE.

First published as AS 4351.3-1996.