To know the complete distribution of E. coli across water and
sludge treatment lines, results of concentration were expressed as
number of colonies presents by day (CFUd1
) as function of inflow
in each process, by means of liquid volumetric flow rate (VF),
included in Fig. 1. Across the water line there is a maximum
theoretical loss of 3.73.1013
CFUd1
through decanters, however,
the amount of E. coli entering to the ATAD at day is 7.16.1014
CFU,
indicating that a total of 6.79.1014
CFU have been generated during
decantation processes (decanter 1 + decanter 2). The greatest loss
of E. coli is produced throughout trickling filters tanks,where itwas
also observed E. coli in the biofilmgenerated around the filters. This
biofilm is decanted itself producing sludge, which can accumulate
microorganisms theoretically eliminated and even increasing their
concentration due to organic matter content. Also, the presence of
microorganisms as bacteria or algae in biofilms, especially in
filters, suppose an increase of biomass which could promote the
development of protozoa and E. coli among others which, in turn,
contribute to the removal of organic matter.