Recycling technology of biodegradable plastics

1. Biological recycling and reuse in aerobic treatment

The decomposition in composting treatment is aerobic decomposition, and the "Standardization of Biological Decomposition Degree Evaluation Experiment Method" of this decomposition method will promote the market development and expansion of environmentally friendly products.

In order to establish the "Standardization of Biodegradability Evaluation Test Methods", BPS conducted a verification test in Japan for three years using a biodegradation apparatus (MODA method), and submitted this test method to the Japan Plastics Industry Federation as an ISO standard. In 2003, the Japan Plastics Industry Federation submitted this experimental method as a new work project proposal (NWIP) to the ISO/TC61/SC5/WG22 MAASTRICHT International Conference (Netherlands, September 30, 2003), and was approved. It was found that the degree of biodegradation varies from country to country due to differences in water retention and organic matter content.

The biodegradability of plastics under composting conditions is measured by the amount of carbon dioxide produced. The mixture of compost and plastic samples was biodegraded under aerobic conditions at 58°C, and the measurement was carried out within 6 months. The decomposition is shown in Figure 8-16. It can be seen from the figure that after the induction phase (lag phase: the biodegradation rate reaches 10% of the theoretical value) and the biodegradation phase, the plateau phase is entered after 150 days, and the total measurement time is 6 months (180 days). ).