Abstract:

Herein, based on existing standards for the measurements of material degradation rates and the degradation abilities of microorganisms, four methods were designed to determine material degradation rates. These four methods included two standard methods (inoculums: composting, vermiculite+composting leachate) and two experimental methods (inoculums: vermiculite+Bacillus, vermiculite+thermophilic bacteria). For this, the raw paper and plastic film (polylactic acid, PLA) components of environmentally friendly tape, as well as the finished tapes, were used as test materials to compare the material degradation rates using the above methods. Throughout the 60-day test cycle, both the PLA films and raw paper presented high degradation rates according to the four methods. The degradation rate of finished tape products increased gradually under the composting and vermiculite+composting leachate treatment and marginally rapidly under the vermiculite+Bacillus treatment. Additionally, under the vermiculite + thermophilic bacteria treatment method, the finished tape materials displayed a markedly higher degradation rate than that produced by other methods (roughly 1.7 ~ 7.5 times). Thus, the addition of microorganisms, particularly thermophilic bacteria, enhances the testing efficiency of material biodegradation rates. Therefore, we suggest that the optimization of degradation cultures can improve the testing efficiency of material degradation parameters, allowing manufacturing enterprises to shorten the research and development cycles of biodegradable products.

Key words: biodegradable products, method optimization, biodegradation rate, thermophilic bacteria