TOC loss (39%) observed by Doublet et al. (2011) during the composting
of sewage sludge in 170-l reactors over an identical period.
An expected increase in N content was observed in all reactors due
to lower N loss by volatilisation compared to TOC loss via mineralisation
during composting. The C:N ratio thus decreased during
composting (Table 1). The final C:N ratio had a coefficient of variation
of 12% indicating that the chemical evolution among the six
replicated composting experiments was reproducible. Losses of C
within the leachates only accounted for 0.1–1.6% of the initial
TOC and were considered as negligible.
3.2.2. Organic matter stabilisation during composting
The microbial degradation of the most easily biodegradable organic
compounds during composting led to organic matter