Date of Award


Document Type

Honors Thesis (Open Access)


Colby College. Chemistry Dept.


D. Whitney King

Second Advisor

Thomas W. Shattuck

Third Advisor

Frank A. Fekete


The quantum yields for iron (lII) photoreduction in sodium chloride and sodium perchlorate media were measured as a function of wavelength. The experiments were conducted using natural levels of total iron, less than 300 nM. The results indicate that three species are photochemically active in these media, Fe(OH)+2, FeCl2+and FeCl2+. The quantum yields for (OH)+2 are 0.22 at 300 run and 0.076 at 340 nm. The quantum yields for FeCl+ are 0.048 at 300 run and 0.038 at 340 nm. The quantum yields for FeCl2+ are 0.088 at 300 nm and 0.051 at 340 nm. The data presented suggests that FeOH+2 is most easily photoreduced at a wavelength of 300 nm. Secondly, in environments with high chloride concentrations the presence of FeCl2+ and Fe(Cl2)+ species will result in an enhanced photoreduction rates due to a shift in action spectra to longer wavelengths around 340 nm. This data set provides the basis for a chemical model for inorganic iron photochemistry in natural waters defined as a function of pH. irradiation, wavelength, intensity, and salinity (chlorinity).


Iron, Chlorides

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