Environmental Engineering Reference
In-Depth Information
Figure 6.14
A biometer flask respirometer for carrying out mineralization
studies. A respirometry curve for cellophane (regenerated cellulose sheet)
compared to that of oak leaves.
Source: Reprinted with permission from Andrady and Song (1999).
A biopolymer such as cellulose or a readily biodegradable synthetic polymer
such as PCL yields good results with such a technique. The plot on the
right-handsideof
Figure6.14
comparesthemineralizationcurvefordryoak
leaves (
Quercus alba
) with that for regenerated cellulose (cellophane) used
as a positive control. Note that for oak leaves, the rate of biodegradation
is slower and the extent of mineralization (carbon conversion) is much
lower than for cellulose. The slower rate is likely due to the presence of
lignin,withonlythecellulosefractionbeingmineralized withintheduration
of observation. Even with regenerated cellulose that should be 100%
biodegradable, carbon conversion is less than 100% as some of the carbon is
usedtogeneratenewbiomassasthemicrobialpopulationintheflaskgrows.
