4.5. Overall performance of WAS thermophilic anaerobic digestion under optimal acidification
conditions
Increased TS and VS destruction were showed in Table 3 during thermophilic anaerobic digestion
process from Start-up phases to Acidification phases operated under optimal acidification conditions of
WAS thermophilic anaerobic digestion, which was good for the improvement of sludge dewaterability, so
as to bring lower costs of disposal.
From the statistics given in the Table 3, over the period from Start-up phases to Acidification phases,
the STOC content increased and the STIC content decreased, while the STC content basically remained
level, indicating that the convertion from STIC to STOC. And compared to Raw WAS, the soluble
organics was greatly released after thermophilic anaerobic digestion under optimal acidification
conditions. Besides, STOC/STNb were tending to increase during the whole process, which may be
helpful to the growth of the acid-forming bacteria to accumulate more VFAs.
A corresponding higher VFAs production can be found throughout the process, which can be used to
additional carbon resource for denitrification. In addition, there was a considerable component of soluble
organics which could not be attributed to VFAs