ISO 14593 pdf download

ISO 14593 pdf download.Water quality — Evaluation of ultimate aerobic biodegradability of organic compounds in aqueous medium 1 Scope This International Standard specifies a method, by analysis of inorganic carbon, for the evaluation in an aqueous medium of the ultimate aerobic biodegradability of organic substances at a given concentration of microorganisms. This International Standard is applicable to organic compounds which are: a) water-soluble under the test conditions; b) poorly water-soluble under the test conditions, in which case special measures may be necessary to achieve a good dispersion of the compound (see ISO 1 0634); c) volatile; d) not inhibitory to the test microorganisms at the concentration chosen for the test. In this test, biogenically produced inorganic carbon is measured in situ in the test vessels in such a manner that the rate measured nearly equals the rate of microbial production. NOTE 1 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 1 5462. NOTE 2 With highly volatile substances, losses to the gaseous phase can be minimized by reducing the volume of the headspace. However, there should be sufficient oxygen in the test system to prevent biodegradation being oxygen-limited. NOTE 3 The presence of an inhibitory effect can be determined as specified in 8.3, or by using any other method for determining the inhibitory effect of a substance on bacteria (see, for example, ISO 81 92). 2 Normative reference The following normative document contains provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent edition of the normative document indicated below. For undated reference, the latest edition of the normative document referred to applies.Members of IEC and ISO maintain registers of currently valid International Standards. ISO 1 0634:1 995, Water quality — Guidance for the preparation and treatment of poorly water-soluble organic compounds for the subsequent evaluation of their biodegradability in aqueous medium. 3 Terms and definitions For the purposes of this International Standard, the following terms and definitions apply. 3.1 ultimate aerobic biodegradation breakdown of a chemical compound or organic matter by microorganisms in the presence of oxygen to...