Aerobic biometer analysis of glucose and starch biodegradation

The ASTM D5210-91 protocol for evaluating the biodegradability of a polymer was examined. The reactor design was modified not only to account for the total CO₂ evolved but also to allow for the simultaneous carbon assessment in microbes, soluble products, and solid samples. Improvements in the test procedure were implemented such as (1) refining the CO₂ pretrap and posttrap design, (2) optimizing the carbon dioxide removal efficiency, (3) accounting for the total polymeric carbon, (4) standardizing the inoculum, and (5) revising the nutrient medium. By growing the sludge on a suitable substrate prior to polymeric exposure, a constant microbial density was obtained. The modified ASTM method provides an assessment of the polymeric carbon degradation at any given time. The results of this work have specific significance to the behavior of polymers in a sewage waste treatment plant, where sludge is continuously being acrated, and also for aerobic biodegradation in general.