Aerobic biodegradability of plastic materials in an aqueous medium
ISO 14852:2018 specifies a method for determining the biodegradability of a plastic material using aerobic, mesophilic microorganisms in an aqueous system. The text mixture contains an inorganic medium, the organic test material (the sole source of carbon and energy) with a concentration between 100 mg/l and 2000 mg/l of organic carbon, and the activated sludge or suspension of active soil or compost as the inoculum. If higher concentrations of test material are used, then an optimized test medium should be applied. The mixture is agitated in test flasks and aerated with CO2-free air over a period of time depending on the biodegradation kinetics, but not exceeding 6 months. The CO2 evolved during the microbial degradation is determined by a suitable analytical method. The level of biodegradation is determined by comparing the amount of CO2 evolved with the theoretical amount and expressed in percentage. The test result is the maximum level of biodegradation, determined from the plateau phase of the biodegradation curve.
Gas Endeavour® can be configured for measuring the evolved carbon dioxide by coupling with our ex-situ carbon dioxide absorption kit. In such configuration, the analysis of each test material will need two measuring lines in order to calculate the evolved carbon dioxide. Please notice the aerobic biodegradation of plastic materials in an aqueous medium can also be analysed according to ISO 14851:2018 based on measurement of oxygen demand (BOD) in a closed respirometer. This is the recommended method for Gas Endeavour® with a simpler system configuration and only single measuring line per sample.
Read more about ISO 14852 at iso.org.