4. Conclusions
A large amount of composts from home and industrial composting
were analyzed and compared. There were no significant differences
in chemical parameters related to its agronomic use like
organic matter and nutrients content. However, there were significant
differences in some metal contents and especially in the level
of stability achieved. The content of some metals was higher in
industrial compost than in home compost. Cu, Ni and Zn contents
classifies industrial composts in Class B (Spanish regulation). However,
some home compost samples also presented a Zn level that
slightly exceeds Class A limit. Regarding the use of individual or
collective home composters, it was observed that composters located
in schools presented a lower quality.
Stability, measured as a DRI and dynamic AT4, is the most
important parameter where significant differences were found between
the composts analyzed. Compost application requires a stable
product for protecting the soil and gets all his benefits. This
study on stability of samples from the OFMSW shows the potential
of the current technologies to achieve appropriate values of stability,
although it depends on the proper control of the composting
process. In reference to compost stability from different processes
(home or industrial), this study demonstrates that home compost,
if properly managed, can achieved a level of stability similar or
even better to that of industrial compost, especially when the composting
technology is not well managed. This implies a great effort
in some composting plants to improve the quality of industrial
compost in terms of stability.