Soft waters tend to reduce the life time of pipes from drinking water distribution systems and the
induced corrosion is likely to deteriorate water quality at the consumer's tap. New French legislation
(decree 2001-1220 of 20/12/2001) effective since the end of 2003, recommends the supplied water not
to be aggressive. Two types of treatments are commonly used to limit the corrosion effect of soft
waters with low alkalinity: the addition of phosphate corrosion inhibitors; and, the neutralization
or remineralization of soft water. In order to provide guidelines for the network operator to choose
suitable treatment methods, a comparison must be made based on a technical (reliability and efficacy)
and an economical standpoint (treatment cost and impact on pipes renewing). Within this study, a pilot
experiment has been performed to compare the impact of phosphate inhibitors with remineralization
on the degradation of pipes commonly used in drinking water distribution systems (cast iron, cement
and steel) and household plumbing systems (copper). The impact of water treatments was studied on
the water (pH, metal leaching, etc) and on corrosion measurements (electrochemical probes, weight
loss coupons). The results obtained over a 15-month period showed that the best water quality was
achieved with the remineralization approach. This water treatment strategy reduces metal pipe
corrosion of soft water by 40% and improves both the copper and the iron release reduction by 50%. Includes 17 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.6 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 14 |
| Published : | 11/01/2005 |
