AWWA WQTC69499

As part of AwwaRF Project 3018, the release of Pb from new faucets and new and usedwater meters was measured. Data were obtained for brass compositions, scalecompositions, and water chemistry. Pb (or Bi) is present in these brasses as small"islands" of metal, whereas Cu and Zn are mixed in a solid solution. With time, the brassshows preferential loss of Zn relative to Cu. Lead releases from the faucets in 6 hourstagnation runs increased rather than decreased with time. This behavior is inconsistentwith formation of passivating scale layers, but is consistent with progressivedezincification producing a porous surface layer through which Pb can diffuse morerapidly, or from which Pb particulates can be detached more readily with time. The rateof Pb release was found to correlate inversely with the Zn/Cu ratio of the brass. Includes 11 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2008

Number of Pages:

20

File Size:

1 file , 2.2 MB