Biodegradability testing of compostable polymer materials

Chapter 6 smnmarizes current testing methods used for the biodegradability testing of compostable polymer materials, standardized as well as non-standardized, reported in the hterature. The focits is on studies imder composting conditions. 

The composting test method based on activated vermicuUte was proposed as a comprehensive system for the assessment of the environmental impact of compostable polymers [1, 2]. Vermicnlite, a clay mineral, can be activated (by an inoculation with an appropriate microbial population and fermentation) and used as a sohd matrix in place of mature compost in the controlled composting test. The formula of vermicnlite is (MgJ e,Al)3(Al,Si)40io(OH)2.4H20. The results obtained with two materials (cellulose and a starch-based blend) indicated that activated vermicnlite affected neither the biodegradation rate nor the final biodegradation level. 

Figure 4.9 Average toxicity data obtained from laboratory composting tests in which natural and synthetic polymers have been degraded. Positive values are inhibitions negative values are increased growth or biological activity. Adapted from J.I. Fritz in Ecotoxicity of Biogenic Materials During and After their Biodegradation, University of Natural Resources and Life Sciences, Wien, Austria,...

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