Table 2.

Parameter values and alumina surface scavenging rate constants used to contrast •OH and SO₄ ^•− activity in UV-APS and UV-AHP oxidative treatment systems.

Parameter	UV-APS 2	UV-APS	UV-AHP 2
${\left[{\text{S}}_2{{\text{O}}_8}_1^{2-}\right]}_0,{\left[{\text{H}}_2{\text{O}}_2\right]}_0$ (nM)1	2.1	29.4	29.4
[RhB]0 (mM)	1.04 × 10 −2	1.04 × 10 −2	1.04 × 10 −2
[alumina] (g L −1)	10	10	10
SA (m 2 g −1)	1.5	1.5	1.5
pHinitial, pHfinal	6.0, 4.5	6.0, 4.1	6.8, 6.0
[SO4 •−]SS,10, [•OH]SS,10 (M)	6.25 × 10 −13 (n = 13)	1.25 × 10 −11 (n = 13)	4.73 × 10 −15 (n = 7)
Test reactor volume (L)	0.025	0.025	0.025
${\text{k}}_{\equiv \text{S},\text{SO}4}{}^{•-},{\text{k}}_{\equiv \text{S},•\text{OH}}\left({\text{m}}^{-2}{\text{s}}^{-1}\right)$	2.42 × 10 4 (n = 13)	2.42 × 10 4 (n = 13)	7.45 × 10 6 (n = 7)

¹The basis for selecting the concentration of oxidant was (1) to assure that the rate of aqueous phase scavenging did not mask RhB oxidation and that changes in [RhB] could be measured (i.e. k₄ [H₂O₂]/k₂ [RhB] and k₁₀ [S₂O₈ ²⁻]/k₈ [RhB] < 6), and (2) equal [H₂O₂]₀ and [S₂O₈ ²⁻]₀.

²Data and calculated parameters derived for 2.1 mM PS and 29.4 mM H₂O₂ are from [15] and [14], respectively; data and calculated parameter values for 29.4 mM PS are from this study.