Fig. 9
From: Impacts of hydrous manganese oxide on the retention and lability of dissolved organic matter
a XPS of the Fe 2p 3/2 region of 8.3 initial C:Fe molar ratio sample in blue, 0.9 initial molar ratio sample in yellow, and untreated goethite shown in red. The region shows no major change as DOM loading is increased. b The Fe XPS spectra of the Fe(II) and Fe(III) standards used to fit the goethite Fe XPS spectrum. c The Fe atomic percent as a function of increasing initial C:Fe molar ratio