AWWA WQTC58954

Disinfectant efficacy is affected by numerous factors including pipe conditions, water age, andfinished water quality. The purpose of this study was to operate Dalhousie Pipe Loops£ for aminimum of six months to correlate the interaction of the various factors (pipe material, waterquality, etc.) that affect the efficacy of secondary disinfectants. This study was conducted at fourfield locations at four water utilities across North America. The field sites were chosen for theirsecondary disinfectant, monochloramine or free chlorine, their water quality, hard or soft, andseveral other factors. Four pipe loops were setup at each location and received finished waterfrom the local utility. Each location was setup to test the different pipe material (concrete linedductile iron, polyvinylchloride, and a local material of interest) and different retention times (6and 24 hours). A relationship between turbidity and microbiological growth was observed in thepipe 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 loopsregardless of pipe material or location. In fact, during plant switch over at one location, the pipeloops were fed water that was aged in the full-scale distribution. A statistical analysis showedthat the only parameter in the influent parameter that was significantly different was disinfectantresidual concentration. Includes 14 references, tables, figure.

Product Details

Edition:

Vol. - No.

Published:

11/02/2003

Number of Pages:

13

File Size:

1 file , 280 KB