Presenter Information

Brandi Clark



Research Advisor

Switzer, Jay

Advisor's Department



The strength of monochloramine, NH2CI, as an oxidizing agent can be linked to its effect on Pb levels in drinking water. In this study, the equilibrium potential was measured as a function of pH from pH 8 to 12 and compared to a theoretical plot of formal potentials derived from the Nemst equation. The measured equilibrium potential was consistently about 300 mV more negative than the calculated potential - NH2CI is a weaker oxidizing agent than predicted. When the measured potentials are plotted on a Pourbaix diagram, it is found that NH2CI can oxidize Pb to PbO2 only above pH 9.5, while the theoretical values indicate that it can do so at a much lower pH. The validity of the values measured in this experiment is supported by the fact that NH2CI has been shown to oxidize Pb to Pb2+, not PbO2, at pH 8 (1). The work is important because it is known that PbO2 acts as a passivating agent on the inside of lead-bearing plumbing materials.

Presentation Type

Oral Presentation

Document Type