TY - GEN
T1 - The influence of water chemistry on dissolution rates of lead corrosion products
AU - Noel, James D.
AU - Giammar, Daniel E.
PY - 2007
Y1 - 2007
N2 - Lead is a toxic heavy metal and the adverse effects of lead consumption are a public health concern. Water leaving treatment plants has very low concentrations of lead. However, internal corrosion of lead-containing pipe, fittings, and solder in water distribution systems is currently the most significant source of lead to drinking water. While new construction does not use lead pipe, many older buildings retain the original lead service lines and internal plumbing. Concern for lead concentrations in water distribution systems motivated the U.S. Environmental Protection Agency (EPA) to pass the Lead and Copper Rule (LCR) in 1991. The LCR set the lead action level to 0.015 mg/L. The understanding of the relationships between water chemistry and the solubility of lead-containing minerals has increased since the passage of the LCR. However, the recent observations of extremely high lead levels in Washington D.C. tap water highlight the need for continuing research. Lead concentrations in drinking water are affected by chemical reactions that occur within the water distribution system. Previous studies have investigated the equilibrium solubility of lead corrosion products; this project focuses on dissolution rates. Knowledge of lead release rates are useful for evaluating potential effects of treatment process changes on water quality in the distribution system. The dissolution rates of the important lead corrosion product, hydrocerussite (Pb3(CO3)2(OH)2), will be determined as a function of pH, dissolved inorganic carbon, orthophosphate, and the presence of chloramines. The lead corrosion products will be characterized with respect to surface area, molecular structure, morphology, and mineralogy. The dissolution rates of these lead corrosion products will be quantitatively determined in completely-mixed continuous-flow reactors. The experimentally measured dissolution rates will be used to generate a model for dissolution rates as a function of water chemistry. This model will then be used to evaluate the dissolution of pipe scales excavated from a water distribution system.
AB - Lead is a toxic heavy metal and the adverse effects of lead consumption are a public health concern. Water leaving treatment plants has very low concentrations of lead. However, internal corrosion of lead-containing pipe, fittings, and solder in water distribution systems is currently the most significant source of lead to drinking water. While new construction does not use lead pipe, many older buildings retain the original lead service lines and internal plumbing. Concern for lead concentrations in water distribution systems motivated the U.S. Environmental Protection Agency (EPA) to pass the Lead and Copper Rule (LCR) in 1991. The LCR set the lead action level to 0.015 mg/L. The understanding of the relationships between water chemistry and the solubility of lead-containing minerals has increased since the passage of the LCR. However, the recent observations of extremely high lead levels in Washington D.C. tap water highlight the need for continuing research. Lead concentrations in drinking water are affected by chemical reactions that occur within the water distribution system. Previous studies have investigated the equilibrium solubility of lead corrosion products; this project focuses on dissolution rates. Knowledge of lead release rates are useful for evaluating potential effects of treatment process changes on water quality in the distribution system. The dissolution rates of the important lead corrosion product, hydrocerussite (Pb3(CO3)2(OH)2), will be determined as a function of pH, dissolved inorganic carbon, orthophosphate, and the presence of chloramines. The lead corrosion products will be characterized with respect to surface area, molecular structure, morphology, and mineralogy. The dissolution rates of these lead corrosion products will be quantitatively determined in completely-mixed continuous-flow reactors. The experimentally measured dissolution rates will be used to generate a model for dissolution rates as a function of water chemistry. This model will then be used to evaluate the dissolution of pipe scales excavated from a water distribution system.
UR - https://www.scopus.com/pages/publications/84871549128
M3 - Conference contribution
AN - SCOPUS:84871549128
SN - 9781605600499
T3 - American Water Works Association - Water Quality Technology Conference and Exposition 2007: Fast Tracks to Water Quality
SP - 204
EP - 220
BT - American Water Works Association - Water Quality Technology Conference and Exposition 2007
T2 - Water Quality Technology Conference and Exposition 2007: Fast Tracks to Water Quality
Y2 - 4 November 2007 through 8 November 2007
ER -