Aerobic biodegradation of non-floating materials exposed to marine sediment
ISO 22404:2019 test method is a simulation under laboratory conditions of the habitat found in sandy tidal zone that, in marine science, is called eulittoral zone. The conditions described in the method might not always correspond to the optimum conditions for the maximum degree of biodegradation to occur. The method is based on the determination of the evolved carbon dioxide and derives from ISO 19679. The testing medium is based on a sandy marine sediment laid in the bottom of a closed flask; the sediment is kept wet with natural sea water. The test material is preferably in the form of a powder. The carbon dioxide evolved during the microbial degradation is determined by a suitable analytical method. The level of biodegradation is determined by comparing the amount of carbon dioxide 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 non-floating materials exposed to marine sediment can also be analyzed according to ISO 18830:2016 based on measurement of oxygen demand (BOD) which is the recommended method for Gas Endeavour® with a simpler system configuration and higher measurement capacity due to the need for only single measuring line per sample.
Read more about ISO 22404 at iso.org.