ISO 14852:2021 水性媒体中のプラスチック材料の最終的な好気性生分解性の決定—発生した二酸化炭素の分析による方法 | ページ 6

3.1

ultimate aerobic biodegradability

breakdown ratio by expressed as percentage of an organic compound by microorganisms in the presence of oxygen into carbon dioxide, water and mineral salts of any other elements present (mineralization) plus new biomass

3.2

activated sludge

mixture of organic materials and biomass produced in the aerobic treatment of waste water by the growth of bacteria and other microorganisms in the presence of dissolved oxygen

3.3

concentration of suspended solids

amount of solids obtained by filtration or centrifugation of a known volume of activated sludge (3.2) and drying at about 105 °C to constant mass

3.4

dissolved inorganic carbon

DIC

part of the inorganic carbon in water which cannot be removed by specified phase separation

Note 1 to entry: Phase separation can be achieved for example by centrifugation at 40 000 m⋅s⁻² for 15 min or by membrane filtration using membranes with pores of 0,2 µm to 0,45 µm diameter.

3.5

theoretical amount of evolved carbon dioxide

ThCO₂

maximum theoretical amount of carbon dioxide evolved after completely oxidizing a chemical compound, calculated from the molecular formula

Note 1 to entry: It is calculated from the molecular formula.

Note 2 to entry: It is expressed as milligrams of carbon dioxide evolved per milligram or gram of test compound.

3.6

total organic carbon

TOC

amount of carbon bound in an organic compound

Note 1 to entry: It is expressed as milligrams of carbon per 100 mg of the compound.

[SOURCE:ISO 17556:2012, 3.14]

3.7

dissolved organic carbon

DOC

part of the organic carbon in water which cannot be removed by specified phase separation

Note 1 to entry: Phase separation can be achieved for example by centrifugation at 40 000 m⋅s⁻² for 15 min or by membrane filtration using membranes with pores of 0,2 µm to 0,45 µm diameter.

3.8

lag phase

time from the start of a test until adaptation and/or selection of the degrading microorganisms is achieved and the degree of biodegradation of a chemical compound or organic matter has increased to about 10 % of the maximum level of biodegradation (3.9)

Note 1 to entry: It is measured in days.

3.9

maximum level of biodegradation

degree of biodegradation of a chemical compound or organic matter in a test, above which no further biodegradation takes place during the test

Note 1 to entry: It is measured in per cent.

3.10

biodegradation phase

time from the end of the lag phase (3.8) of a test until the plateau phase (3.11) has been reached

Note 1 to entry: It is measured in days.

3.11

plateau phase

time from the end of the biodegradation phase (3.10) until the end of a test

Note 1 to entry: It is measured in days.

3.12

pre-exposure

pre-incubation of an inoculum (3.14) in the presence of the chemical compound or organic matter under test, with the aim of enhancing the ability of the inoculum to biodegrade the test material by adaptation and/or selection of the microorganisms

3.13

pre-conditioned

pre-incubated inoculum (3.14) under the conditions of the subsequent test in the absence of the chemical compound or organic matter under test, with the aim of improving the test by acclimatization of the microorganisms to the test conditions

3.14

inoculum

microorganisms or other material used in an inoculation (3.15)

Note 1 to entry: Also called inoculant.

3.15

inoculation

introduction of microorganisms into a culture medium in order to start a biological process