Aerobic biodegradability of plastic materials under controlled composting thermophilic conditions
ISO 14855-1:2012 test method determines the ultimate biodegradability and degree disintegration of test material under conditions simulation an intensive aerobic composting process. The inoculum used consists of stabilized, mature compost derived, if possible, from composting the organic fraction of solid municipal waste. The test material is mixed with the inoculum and introduced into a static composting vessel where it is intensively composted under optimum oxygen, temperature and moisture conditions for a test period not exceeding 6 months. During the aerobic biodegradation of the test material, carbon dioxide, water, mineral salts and new microbial cellular constituents (biomass) are the ultimate biodegradation products. The evolved CO2 is continuously monitored, or measured at regular intervals, in test and blank vessels to determine the cumulative CO2 production. The percentage biodegradation is given by the ratio of the CO2 produced from the test material to the maximum theoretical amount of CO2 that can be produced from the test material. The maximum theoretical amount of CO2 produced is calculated from the measured total organic carbon content. The percentage biodegradation does not include that amount of carbon converted to new cell biomass which is not metabolized in turn to CO2 during the test.
Gas Endeavour® may be configured to evaluate aerobic biodegradability of polymer samples under the same temperature range of controlled composting conditions using industrial compost as inoculum. The instrument allows for continuous and on-line monitoring of oxygen demand or depletion caused by aerobic respiration of compost bacteria. This arrangement should be served as a practical analytical tool of biodegradability evaluation under similar conditions of controlled composting facility for internal study or research purpose.
Read more about ISO 14855-1 at iso.org.