J Polym Environ
14
C [5]. The study compared CA with degrees of substitutions of 1.85, 2.07 and 2.57, and found the biodegradation rates were reduced, but not inhibited, by the higher
levels of acetyl (Fig. 1).
Buchanan, Gardner, and Komarek in 1993 [4] studied
two aerobic assay systems for degrading CA films: an in
vitro enrichment cultivation technique and an activated
sludge wastewater treatment system. The enrichment culture was able to degrade CA films within 2–3 weeks, as
indicated by 67% weight loss. The industrial wastewater
treatment system provided the same degradation, however,
it occurred at slower rates with 10 weeks required for
significant changes in the films. The authors stressed the
point that the accelerated degradation systems only included an increase in concentration and not a change in the
abilities of the naturally occurring microorganisms; thus
when CA materials are placed in a natural environment the
potential for biodegradation is maintained and only the
speed of degradation is changed.
CA has also been shown to be degraded under anaerobic
conditions. Rivard et al. in 1992 [7