AWWA JAW62303

The foundation for lead control in drinking waterdistribution systems is based on Pb(II) chemistry. Inrecent years, however, Pb(IV) oxides have been identifiedin distribution systems, suggesting that they maybe important relative to predicting and controllinglead concentrations at the consumer's tap. Therefore,a better understanding of the chemistry of Pb(IV) canbe valuable to water utility managers as they maketreatment decisions.This research shows that the two Pb(IV) dioxidepolymorphs plattnerite and scrutinyite can form inchlorinated water and that these solids are less solublein general than Pb(II) minerals historically used for leadcontrol strategies. These findings have implications forwater suppliers considering switching to a differenttype of disinfectant or making other treatment changesthat could affect redox potential. If Pb(IV) oxides arein their distribution systems, any changes in redoxpotential (e.g., switching disinfectant from free chlorineto chloramines) could possibly fully reduce those solidsto more soluble Pb(II) forms, potentially resulting inelevated lead concentrations. Includes 45 references, table, figures.

Product Details

Edition:

Vol. 97 - No. 11

Published:

11/01/2005

Number of Pages:

13

File Size:

1 file , 440 KB