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Eq. 2.12 can be combined with Eq. 2.9 to yield k bulk 1 + 1.5 −3 1. 5 −3 1. 5 { γ + k2 [ H ] + reactants ( 32.4 × 10 [ CNOM ] + 79.6 × 10 [ Ccat ] ) } = k + γ γ S O 2− 2 8 26 (2.13) that can be used to estimate persulfate degradation in the presence of aquifer materials where FeAm represents the mineral catalyst and TOC represents the NOM. Depletion of Reactants. The use of kbulk as defined in Eq. 2.13 represents a “pseudo” first-order rate coefficient since TOC and FeAm may be depleted while the H + concentration generally increases over time. One potential avenue to assess loss of the overall reduction capacity of the aquifer solids is to examine changes in the COD test results. FeAm may exist as Fe 2+ or Fe 3+ and activation of persulfate by Fe 2+ will result in the formation of Fe 3+ . It has been shown that Fe 3+ can also activate persulfate, or can form organo-complexes resulting in the regeneration of Fe 2+ (Henderson and Winkler, 1959; Kislenko et al., 1995; Block et al., 2004). Hence, the total concentration of Fe ions capable of persulfate activation may not deplete over time supporting the notion of a constant kobs with respect to FeAm in a batch system. H The NOM content is very likely to decrease but the exact rate and extent of NOM loss may not be entirely predictable. Persulfate oxidation of NOM is complicated and depends upon a number of factors including the NOM form, desorption, protection by mineral surfaces, pH and clay content (Clifton and Huie, 1989; Menegatti et al., 1999; Cuypers et al., 2002; Eusterhues et al., 2003; Mikutta et al., 2005).
COD test results illustrated loss of the overall reduction capacity of the aquifer solids (Figure 2.3). In general, there was a reduction in the COD values following persulfate exposure with a maximum of ~42±10% reduction for the NIROP aquifer material at the low concentration and ~65±12% reduction for Borden aquifer material at the high concentration. For the high concentration experiments, the reduction in COD after ~300 days of persulfate exposure was greater than that for low concentration experiments for the same aquifer material implying that a higher persulfate concentration and a longer exposure time can lead to a greater depletion of the reductive capacity. The observed COD reduction was statistically significant (t-test, α = 0.05) for all aquifer materials except for the LAAP and LC34-USU aquifer materials at both persulfate concentrations, and the LC34-LSU and MAAP aquifer materials at the low persulfate concentration. Since the NOM associated with the aquifer materials used in this study is mainly responsible for the TRC as captured by the COD test (Xu and Thomson, 2008), a significant reduction in COD implies a significant oxidation of NOM occurred as a result of persulfate exposure. This reduction in NOM was statistically significant for 5 of 7 aquifer materials at the high persulfate concentration, and only 3 of 7 aquifer materials at the low persulfate concentration. Although, the persulfate mass employed in the high concentration experiments exceeded the stoichiometric requirement to satisfy the initial COD for all aquifer materials except LC34-LSU, the maximum observed depletion of 65±12% over ~300 days exposure period indicates that not all of the aquifer material reductive capacity as captured by the COD test can be satisfied by persulfate (Dahmani et al., 2006). Aquifer materials with high clay content (e.g., LAAP) can be expected to be more resistant to NOM oxidation by persulfate (Eusterhues et al., 2003) as was observed at both concentrations. Although no experimental 27
Page 1: Persulfate Persistence and Treatabi
Page 5 and 6: Abstract Petroleum hydrocarbons (PH
Page 7 and 8: observed at 1 g/L as compared to 20
Page 9 and 10: Acknowledgements God, as some cynic
Page 11: simply conceded to, acknowledging t
Page 14 and 15: 3.3.1 Methods…………………
Page 17 and 18: List of Figures Figure 2.1. Persulf
Page 19: and (b) naphthalene……………
Page 23 and 24: Chapter 1 Introduction 1.1. GENERAL
Page 25 and 26: subsurface zones to minimize the or
Page 27 and 28: 2004; Dahmani et. al, 2006). Brown
Page 29 and 30: to activated persulfate utilization
Page 31: is presented here without change. C
Page 34 and 35: 2.1. INTRODUCTION The treatment of
Page 36 and 37: persulfate demand of the aquifer so
Page 38 and 39: at early time to >15 days at later
Page 40 and 41: ~3 m. The water table remained stab
Page 42 and 43: This acid-catalyzed reaction was as
Page 44 and 45: mass of aquifer solids. In general,
Page 46 and 47: correlation as compared with nNOM o
Page 50 and 51: investigation was undertaken to eva
Page 52 and 53: changes in kobs are consistent with
Page 54 and 55: porosity)ρparticle/porosity) of 5.
Page 56 and 57: C/C o pH 1.2 1.0 0.8 0.6 0.4 0.2 10
Page 58 and 59: C/C o 0 0 10 20 30 40 Time (days) F
Page 60 and 61: C/C o 1.2 1 0.8 0.6 0.4 0.2 0 0 5 1
Page 63 and 64: Chapter 3 Stability of Activated Pe
Page 65 and 66: 3.1. INTRODUCTION Sodium persulfate
Page 67 and 68: presence of aquifer materials. Whil
Page 69 and 70: eactions and oxidation mechanisms w
Page 71 and 72: aquifer materials identified as Bor
Page 73 and 74: Therefore, the molar concentrations
Page 75 and 76: After the initial loss, the remaini
Page 77 and 78: constituents (e.g., FeAm, TOC), but
Page 79 and 80: where, TOS kobs is the estimated fi
Page 81 and 82: and rapid oxidation of Fe(II) occur
Page 83 and 84: C/C o C/C o C/C o 1.2 1 0.8 0.6 0.4
Page 85 and 86: C/C o C/C o C/C o 1.2 1 0.8 0.6 0.4
Page 87 and 88: Table 3.1. Summary of experimental
Page 89: Table 3.3. Summary of the impact of
Page 92 and 93: 4.1. INTRODUCTION Gasoline is one o
Page 94 and 95: −• − 2− SO 4 + e → SO4 (E
Page 96 and 97: 4.2.2. Experimental Setup Batch exp
Page 98 and 99:
exhibits a higher persulfate degrad
Page 100 and 101:
4.3.1. Unactivated Persulfate Treat
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Huang et al. (2005) observed signif
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further study is required for a bet
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that the alkaline activation of per
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naturally activate persulfate. Enha
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28 days indicates excellent persist
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C/C o C/C o C/C o 1.2 1 0.8 0.6 0.4
Page 114 and 115:
C/C o 2.4 2 1.6 1.2 0.8 0.4 0 0 10
Page 116 and 117:
94 Table 4.2. First-order oxidation
Page 118 and 119:
5.1. INTRODUCTION Gasoline is among
Page 120 and 121:
2− compounds, residual persulfate
Page 122 and 123:
5.2. METHODS 5.2.1. Oxidant Injecti
Page 124 and 125:
persulfate degradation and in conju
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were equilibrated to room temperatu
Page 128 and 129:
The pre-treatment concentration pro
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materials and MGCs. SO and Na + con
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MGC concentrations was observed bet
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occurred quickly (
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Analyses of the organic and inorgan
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116 (a) Figure 5.1(a): Plan view of
Page 140 and 141:
Depth (m) Depth (m) 0 1 2 3 4 5 (c)
Page 142 and 143:
Ethylbenzene (μg/L) Naphthalene (
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M (g/day) ● 10 2 10 1 10 0 Toluen
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Table 5.1 Summary of contaminated s
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• Based on these observations, a
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• Persistence of persulfate was l
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and cumulative mass flow of target
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sampling frequency for different ty
Page 156 and 157:
Houston, A.C., 1913. Studies in Wat
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USEPA, 2006. MTBE in Drinking Water
Page 160 and 161:
Gates-Anderson, D.D., Siegrist, R.L
Page 162 and 163:
CHAPTER 3 Anipsitakis, G.P., Dionys
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Singh, U.C., Venkatarao, K., 1976.
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Huang, K., Couttenye, R.A., Hoag, G
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Zhou, Q., Suna, F., Liu, R., 2005.
Page 170 and 171:
Liang, C., Huang, C., Chen, Y., 200
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