TY - GEN
T1 - Effects of free chlorine, chloramines, and phosphate on dissolution of PbO2and the reductive dissolution mechanism
AU - Xie, Yanjiao
AU - Wang, Yin
AU - Giammar, Daniel E.
PY - 2010
Y1 - 2010
N2 - PbO2 is a corrosion product that develops on lead pipes that have been in contact with free chlorine present as a residual disinfectant. When the residual disinfectant is switched from free chlorine to monochloramine, the accelerated reductive dissolution of PbO2 can cause elevated lead concentrations in tap water. The objectives of this study were to investigate the effects of chlorine disinfectants and orthophosphate on PbO2 dissolution rates, gain insights into PbO2 dissolution mechanisms, and evaluate the effect of chlorine disinfectants and orthophosphate on lead release from pipe scales containing PbO2. The effects of free chlorine, monochloramine, and orthophosphate on the dissolution rates of plattnerite were quantified in completely-mixed continuous-flow reactors at relevant pH and dissolved inorganic carbon conditions. PbO2 and hydrocerussite were developed in the scales of new lead pipes, and lead release from the pipe scales was examined in the presence and absence of chlorine disinfectants and orthophosphate. PbO2 dissolution rates decreased in the following order: no disinfectant > monochloramine > chlorine, which was consistent with the trend in the redox potential caused by monochloramine and chlorine. Addition of orthophosphate lowered net dissolution rate of PbO2. The effects of free chlorine and orthophosphate on lead release from pipe scales containing PbO2 are consistent with the effects of free chlorine and orthophosphate on PbO2 dissolution rates. 2010
AB - PbO2 is a corrosion product that develops on lead pipes that have been in contact with free chlorine present as a residual disinfectant. When the residual disinfectant is switched from free chlorine to monochloramine, the accelerated reductive dissolution of PbO2 can cause elevated lead concentrations in tap water. The objectives of this study were to investigate the effects of chlorine disinfectants and orthophosphate on PbO2 dissolution rates, gain insights into PbO2 dissolution mechanisms, and evaluate the effect of chlorine disinfectants and orthophosphate on lead release from pipe scales containing PbO2. The effects of free chlorine, monochloramine, and orthophosphate on the dissolution rates of plattnerite were quantified in completely-mixed continuous-flow reactors at relevant pH and dissolved inorganic carbon conditions. PbO2 and hydrocerussite were developed in the scales of new lead pipes, and lead release from the pipe scales was examined in the presence and absence of chlorine disinfectants and orthophosphate. PbO2 dissolution rates decreased in the following order: no disinfectant > monochloramine > chlorine, which was consistent with the trend in the redox potential caused by monochloramine and chlorine. Addition of orthophosphate lowered net dissolution rate of PbO2. The effects of free chlorine and orthophosphate on lead release from pipe scales containing PbO2 are consistent with the effects of free chlorine and orthophosphate on PbO2 dissolution rates. 2010
UR - https://www.scopus.com/pages/publications/84873514864
M3 - Conference contribution
AN - SCOPUS:84873514864
SN - 9781617823404
T3 - Water Quality Technology Conference and Exposition 2010
SP - 3035
EP - 3045
BT - Water Quality Technology Conference and Exposition 2010
T2 - Water Quality Technology Conference and Exposition 2010
Y2 - 14 November 2010 through 18 November 2010
ER -