120
During the study, eachof six loops received continuous applicationof one
of the following disinfectants: chlorine (as sodium hypochlorite), electro-
chlorination, chlorine dioxide, monochloramine, ozone, or copper/silver.
Theseventh loopwasusedas thenegative (untreated)control.Performance
evaluation of these disinfectants was based on their ability to control
Legionella
, protozoa andbiofilms. Figure 3 shows the rig.
Figure 3. Domestic water supply simulation unit. 1: galvanized steel
coupons, 2:mild steel coupons, 3: copper coupons, 4: brass coupons, 5 and
8: glass beads for biofilmmonitoring, 6 and 7: PVC coupons for biofilm
monitoring, 9: re-circulation pump, 10 and 11: solenoid valves, 12: non-
return valve, 13: temperature probe, 14: pressure gauge, 15: air trap, 16:
pointof injectionofdisinfectants,17: connection to thecalorifier.Thewater
temperatureduring all experimentswas 35 °C and thepHwas 8.5.
Figure3
