Also, a decrease of E. coli concentration through the sludge
treatment line was detected (Table 2). In this case, the total
reduction is 1.36log, being greater during the ATAD process than in
the dehydration one (61% and 39%, respectively). Reinthaler et al.
(2010) observed only a 50% of reduction after applying ATAD
process followed by dehydration; however, they reached 100% of
reduction adding a drying process. As has been shown in other
studies, a better result could be acquired by increasing tempera-
ture to 65
C or increasing the residence time inside the digesters
(Gantzer et al., 2001; Lloret et al., 2009).