Disinfectant efficacy is affected by numerous factors including pipe conditions, water age, and
finished water quality. The purpose of this study was to operate Dalhousie Pipe Loops£ for a
minimum of six months to correlate the interaction of the various factors (pipe material, water
quality, etc.) that affect the efficacy of secondary disinfectants. This study was conducted at four
field locations at four water utilities across North America. The field sites were chosen for their
secondary disinfectant, monochloramine or free chlorine, their water quality, hard or soft, and
several other factors. Four pipe loops were setup at each location and received finished water
from the local utility. Each location was setup to test the different pipe material (concrete lined
ductile iron, polyvinylchloride, and a local material of interest) and different retention times (6
and 24 hours). A relationship between turbidity and microbiological growth was observed in the
pipe loops, but there was very little relationship between iron and corrosion rate and regrowth.
Furthermore, in almost all cases, chlorine decay was significant in most of the 24-h pipe loops
regardless of pipe material or location. In fact, during plant switch over at one location, the pipe
loops were fed water that was aged in the full-scale distribution. A statistical analysis showed
that the only parameter in the influent parameter that was significantly different was disinfectant
residual concentration. Includes 14 references, tables, figure.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 280 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 13 |
| Published : | 11/02/2003 |
