Full Description

This powerpoint presentation begins by providing a brief overview of the chloride to sulfate mass ratio. Causes for concern include the following: high CSMR;Pb action level exceeded when coagulantchanged from alum to PACl, isolated cases of leadpoisoning;Dodrill pH measured as low as 3.4 at solder surface(Triantafyllidou, 2007); and,Triantafyllidou (2007) proved galvanic corrosioncan increase Pb release by 16 X or more. Topics covered include the Origin of Effect -Galvanic Corrosion, and distribution system altering of CSMR. Three bench-scale case studies examined the following:1" lengths of 50:50 Pb:Sn solder were placed inside 1"copper couplings and exposed to 100 mL of testwaters;water was changed twice per week and collected asweekly composite samples; and,weekly composites were analyzed for lead (and othermetals) as well as Cl- and SOsub4/subsup2-/sup. Experimental results indicated the following: the best condition was at pH 7.3 with orthophosphate; and,Virginia Tech made the recommendation to changeinhibitor from polyphosphate blend to ortho. Includes figures, tables.

Product Details

Edition: Vol. - No. Published: 11/01/2008 Number of Pages: 45File Size: 1 file , 2 MB