Role of iron and aluminum coagulant metal residuals and lead release from drinking water pipe materials.
Bench-scale experiments investigated the role of iron and aluminum residuals in lead release in a low alkalinity and high (> 0.5) chloride-to-sulfate mass ratio (CSMR) in water. Lead leaching was examined for two lead-bearing plumbing materials, including harvested lead pipe and new lead: tin solder, after exposure to water with simulated aluminum sulfate, polyaluminum chloride and ferric sulfate coagulation treatments with 1-25-μM levels of iron or aluminum residuals in the water. The release of lead from systems with harvested lead pipe was highly correlated with levels of residual aluminum or iron present in samples (R(2) = 0.66-0.88), consistent with sorption of lead onto the aluminum and iron hydroxides during stagnation. The results indicate that aluminum and iron coagulant residuals, at levels complying with recommended guidelines, can sometimes play a significant role in lead mobilization from premise plumbing.
a Department of Civil & Resource Engineering , Dalhousie University , Halifax , Nova Scotia , Canada.
Alisha D
AD
Knowles
Caroline K
CK
Nguyen
Marc A
MA
Edwards
Amina
A
Stoddart
Brad
B
McIlwain
Graham A
GA
Gagnon
D000535:Aluminum / Q000032:analysis* / Q000737:chemistry; D002712:Chlorides / Q000032:analysis* / Q000737:chemistry; D060766:Drinking Water / Q000032:analysis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000032:analysis* / Q000737:chemistry; D007854:Lead / Q000032:analysis* / Q000737:chemistry; D012498:Sanitary Engineering / Q000295:instrumentation; D013431:Sulfates / Q000032:analysis / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
D002712:Chlorides; D060766:Drinking Water; D013431:Sulfates; D014874:Water Pollutants, Chemical; D007854:Lead; D000535:Aluminum; D007501:Iron
Aluminum sulfate; coagulant residual; drinking water; ferric sulfate; lead corrosion; polyaluminum chloride