123
In this study, chlorine dioxide and chlorine (as sodium hypochlorite or
generatedon-sitebyelectro-chlorination)werethemosteffectivetreatments.
However, when also considering safety, cost and simplicity (which includes
regulatory and application issues), chlorine was clearly the best choice for
microbial control in potable building water system disinfection Table 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
hypochlorite were safer, simpler, more cost-effective and worked as well or
better than the other disinfectants tested.
NaOCl = sodium hypochlorite; E-NaOCl = electrolyticaly generated sodium hypochlorite;
ClO2 = chlorine dioxide; Cu/Ag = copper and silver ionization; NH2Cl = chloramines
“Simplicity” includes implementation of the chemical treatment and regulatory issues.
Table 6
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
