127
Figure 5
Figure 5. Microbial control in a cooling tower simulation of conditions
that were highly conducive to heavy fouling in scaling conditions with
pH 8.5. Top panel photographs correlate with heat transfer resistance
measurements (% Clean). Even very heavily microbial fouling (photograph
on the left correlated with a 30% loss of heat transfer) was quickly controlled
with practical applications of sodium hypochlorite (FRO = free residual
oxidant, as Cl2). Bottom panel: Event indicators: 1 – continuous 10 ppm
glucose nutrient feed, 5 ppm phosphate concentration from scale inhibitor
and water conditions previously shown to result in heavy fouling without
microbial control. Biocide applied was sodium hypochlorite at 2 ppm
NeoSens!Fouling!Sensor!Evaluation!
Data!Summary!
!
!
!
1
2
2 3
4!
5ppm
FRO
