Achievement

Trainee Jose Cerrato (Civil and Environmental Engineering) and EIGER PI Michael Hochella (Geosciences) developed a new X-ray photoelectron spectroscopy (XPS) technique that identifies manganese species [Mn (II), Mn (III), Mn (IV)] in solid precipitates, in this case applied to identify the mechanisms of manganese removal from full scale engineered systems designed to treat water to drinking water standards. The results are reported in the journal Environmental Science and Technology, v. 44, p. 5881. The principal findings are that 1) both Mn(III) and Mn(IV) are detected using XPS through the determination of the exact Mn 3p line position and shape, and 2) there is no evidence of autocatalytic oxidation of Mn in the absence of chlorine in the treatment plant. Macroscopic results linked to spectroscopic evidence suggest that Mn(II) removal in the presence of chlorine is due to oxidation on filtration media surfaces.