121
In this study, chlorinedioxideandchlorine (as sodiumhypochloriteor
generatedon-sitebyelectro-chlorination)werethemosteffectivetreatments.
However,whenalsoconsidering safety, cost and simplicity (which includes
regulatory and application issues), chlorinewas clearly the best choice for
microbial control inpotablebuildingwater systemdisinfectionTable 6).
Table 6. Ranking of performance in control of
Legionella
, biofilm and
protozoa, safety, cost and simplicity (application and regulatory issues)
of 6 building water system disinfectants. Microbial control with sodium
hypochloritewere safer, simpler,more cost-effective andworked aswell or
better than theother disinfectants tested.
NaOCl = sodiumhypochlorite; E-NaOCl = electrolyticalygenerated sodiumhypochlorite;
ClO2= chlorinedioxide; Cu/Ag= copper and silver ionization;NH2Cl = chloramines
“Simplicity” includes implementationof the chemical treatment and regulatory issues.
Table6
Rank
Performance
Safety
Cost
Simplicity
Best
NaOCl
NaOCl
NaOCl
NaOCl
E-NaOCl
Cu/Ag
E-NaOCl
E-NaOCl
ClO
2
E-NaOCl
O
3
O
3
NH
2
Cl
NH
2
Cl
NH
2
Cl
NH
2
Cl
O
3
O
3
Cu/Ag
Cu/Ag
Worst
Cu/Ag
ClO
2
ClO
2
ClO
2
