3.2. Analysis of degradation mechanism for food waste
Microbial activity is responsible for degradation of food waste.
In our study, the two experiments have a same material composition,
inoculation, bulking agent and reaction condition, the only
differences are temperature, aeration, friction and collision. These
factors have an effect on microbial activity. A moderate high temperature
was proved to be effective to promote composting process (Ke et al., 2010). As shown in Fig. 4(a), temperature in DHAF
process fluctuates between 53 C and 59 C, the range was found
in TSC from the 4th day to 8th day. As a result, temperature, to
some extent, is a same condition for the two process. So the main
differences between the two process are aeration, friction and collision.
Fig. 4(b) shows the changes in thermophilic bacteria biomass.
We can see thermophilic bacteria biomass in DHAF is
higher than in TSC by almost three orders of magnitude under
the temperature of 53–59 C, which is the symbol of intense microbial
activity. The reason can be attributed to aeration, friction and
collision. In order to find the relationships between microbial activity and aeration, friction, collision, an investigation to compost
particle was carried out as follows.