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In the presence of aquifer materials peroxide undergoes enhanced decomposition without
significantly changing the total reductive capacity (TRC) of the aquifer solids such that
repeated addition of peroxide leads to continual peroxide decomposition (Xu and Thomson,
2010). This enhanced decomposition or degradation is so rapid that it limits the treatment
radius of influence in the subsurface to a few meters around injection locations (Watts and
Teel, 2006). In contrast to peroxide, permanganate is consumed by the natural organic
matter (NOM) and inorganic reductants associated with aquifer materials (Mumford et al.,
2005). Thus aquifer materials exposed to permanganate exhibit a finite or an ultimate natural
oxidant demand (NOD) (Haselow et al., 2003; Mumford et al., 2005; Xu and Thomson,
2008). Once the ultimate NOD of the solids has been satisfied, permanganate is relatively
stable in the subsurface for extended periods of time (Gates-Anderson et al., 2001; Xu and
Thomson, 2009).
The TRC of an aquifer material can be theoretically determined by estimating the sum of
specific reductive species (e.g., natural organic matter (NOM), Fe(II), and Mn(II)) or
experimentally quantified by the chemical oxidant demand (COD) test (Barcelona and Holm,
1991; Xu and Thomson, 2008). For some aquifer materials the reductive minerals may be
the largest oxidant sink while for others it may be the NOM (Xu and Thomson, 2008).
Recent efforts by Xu and Thomson (2008, 2009, 2010) using a variety of aquifer solids have
shown that permanganate mass consumption and peroxide enhanced decomposition are
highly correlated with the total organic carbon (TOC) content and/or the amorphous iron
(FeAm) content.
The limited data on persulfate interaction with aquifer materials is conflicting. The data
presented by Dahmani et al. (2006) support the view that persulfate is stable once the
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