Fig. 8
From: Impacts of hydrous manganese oxide on the retention and lability of dissolved organic matter
a XPS of the Mn 2p 3/2 region of the 8.3 initial C:Mn molar ratio samples in blue, 1.4 initial C:Mn molar ratio sample in yellow, and untreated HMO shown in red. The region is broken into two distinct species; the one of lower binding energy located at 640.7 eV is the Mn(II) peak, and the higher energy peak is a custom line shape of the untreated HMO. b The raw Mn XPS spectrum along with the background and Mn XPS standard spectra used for fitting. c The Mn atomic percent based on all of elements detected with XPS. d The increase in the % of Mn present as Mn(II) as the samples were exposed to increasing amounts of DOM