AS 4351.8-1996

This Standard specifies a method for the evaluation of the elimination and the 'inherent' biodegradability of organic compounds, at a given concentration, by aerobic microorganisms.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 concentration 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; and(d) not inhibitory to the test microorganisms 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 be 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).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 WITH UNKNOWN PROPERTIES SHOULD BE HANDLED WITH CARE.

First published as AS 4351.8-1996.