Biodegradable plastics are currently being developed as a short-term solution to the problem of conventional plastics which persist in the soil. Little is known regarding the decomposition of the new plastics including products formed and microbial populations responsible.Polyethylene-based plastic films interspersed with 0, 5, 10 or 15% (w/w) starch were incubated for up to 112 days in laboratory and filed soils, a forced-air compost pile, and a simulated sanitary landfill. Biologically-mediated polymer decomposition was monitored via measurement of microbial respiration, release of soluble organic carbon ()C) and anions, total microbial counts, and scanning electron microscopic (SEM) observations. Microbial respiration was greatest in all treatments within the first 14 days coincided with greatest soluble OC and acid production.The 15% starch samples decomposed most rapidly in the field soils (2.57. decrease in mass over 11 days) due to the influence of sunlight and temperature extremes. Decomposition was lowest (0.1%) in the anaerobic landfill.Actinomycetes and bacteria predominated in most environments while fungi growth was inhibited in the landfill and compost. The SEM observations revealed a preferential attack of starch granules by microbes followed by a more gradual weathering of polyethylene sheets. / Department of Natural Resources
| Identifer | oai:union.ndltd.org:BSU/oai:cardinalscholar.bsu.edu:handle/184021 |
| Date | January 1990 |
| Creators | Straub, Craig A. |
| Contributors | Ball State University. Dept. of Natural Resources., Pichtel, John R. |
| Source Sets | Ball State University |
| Detected Language | English |
| Format | viii, 62 leaves : ill. ; 28 cm. |
| Source | Virtual Press |
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