CHED 1129 |
| The solution chemistry of Pb(II) at relatively low pH (~ 3-5) was examined in the presence of chloride, sulfate, and phosphate. Lead sulfate solids are relatively insoluble even at pH 3. Pb(II) forms soluble complexes with Cl- that can significantly increase the solubility of lead. Since lead solubility can be correlated to lead contamination problems in drinking water, the data suggest that chloride will worsen lead problems at low pH, whereas sulfate will decrease lead problems. The contradictory trends for the two anions may provide a mechanistic explanation for the success of the empirical chloride:sulfate mass ratio in explaining lead contamination of potable water. Specifically, the trends explain why lead contamination sometimes worsens when changing from alum (higher sulfate) to ferric chloride (higher chloride) coagulants. |
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Undergraduate Research Poster Session: Environmental Chemistry
2:00 PM-4:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster
Division of Chemical Education |