The effects of varying pyrite loading and surface area (which affect. OH production) on Phe degradation rates are evident in Figures 3, 5, and 6.
A conceptual model is presented using a number of simplifying assumptions that incorporates the combined effects of pyrite loading and [Phe]o on.
Loss of Phe varied in pyrite slurries at rates that were first-order in pyrite loading and pseudo first-order dependent on Phe as a function of time; whereas the rate of Phe loss was much less-than first-order in [Phe]o.
Note that in Equation 9, K pyr [pyr]/[Phe]o is analogous to the experimentally determined pseudo first-order rate constant k'defined in Equation 3, where k'was found to be proportional to pyrite loading and inversely related to [Phe]o (at [Phe] ≥ 30μM).
This is supported by evidence that H2O2 production has been shown to be proportional to pyrite loading [29], and does not react with substrates such as adenine [14] and Phe.
The loss of Phe was determined under conditions where both [Phe]o (11 - 286 μM) and pyrite loading (25 - 100 g/L) were varied (the effect of pyrite loading will be addressed later in this section).
Importantly, it allows for most of the observed dependence of [Phe]o and pyrite loading to be accounted for while describing the apparent first-order dependence of Phe loss through time.
The aim of this study was to determine the effect of pyrite loading on the stability of adenine and to evaluate the adenine degradation products.
OH formation is assumed to be constant and proportional to pyrite loading, it can be assigned a reaction coefficient that represents the pyrite reactivity (Equation 5), incorporating all factors related to formation of.
