| Collection Mémoires et thèses électroniques | |
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| Alkaline oxidation of hydrosulfide and methyl mercaptide by iron/cerium oxide-hydroxide in presence of dissolved oxygen. Possible application for removal of Total Reduced Sulfur (TRS) emissions in the Pulp & Paper industry | ||
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Table des matières
Liste des illustrations
) CeO2(363 mg) and HS-(1.55 mmol/L); (
) FeOx(c) (166 mg) and HS-(1.55 mmol/L); (
) FeOx(m) (166 mg) and HS-(1.55 mmol/L); (
) Fe/CeOx(c) (210 mg) and HS-(1.55 mmol/L); (
) Fe/CeOx(m) (210 mg) and HS-(1.55 mmol/L).
) and (
). Peaks: 1 polysulfides; 2 thiosulfate; 3 sulfate; 4 hydrosulfide; 5 sulfite.
) O2total (10.53 mmol) and HS-(2.55 mmol/L), without Fe/Ce oxide-hydroxide; (
) Fe/CeOx(m) (210 mg) and HS-(1.55 mmol/L) without O2; (
) Fe/CeOx(m) (210 mg), O2total (10.53 mmol) and HS-(1.55 mmol/L). (b) DO2 profile for the last case.
) and HS-Fe/CeOx(m) and O2(
). Reaction conditions as in Figure 3a (
) and (
). Yield S2O3
2-= S2O3
2-produced /HS-initial and Yield Sx
2-= Sx
2-produced /HS-initial.
) Fe/CeOx(m)-fresh (100 mg) and HS-(2.50 mmol/L); (
) Fe/CeOx(m)-spent (100 mg) and HS-(2.50 mmol/L). (b) Proof of concept of the bifunctional redox process (pH = 9.5, 22oC, 1 atm, Vliq=0.2 L, 600 rpm) for HS-(1.03 mmol/L) removal by the Fe/Ce oxide-hydroxide (170 mg) in presence of O2(11.37 mmol). Lines represent tendencies.
) hydrosulfide oxidation and (
) iron dissolution; (b) evolution of hydrosulfide oxidation products: (
) thiosulfate, (
) polysulfide and (
) sulfate. Sx
2-yield = Sx
2-peak surface/initial HS-peak surface.
) and iron dissolution (
); (b) thiosulfate (
) and polysulfide (
) formation. Sx
2-yield = Sx
2-peak surface/initial HS-peak surface.![Figure 3.5. Plot of log of the reaction rate (R) vs. log of the initial oxide surface area ([A]t=0), for the reaction between the Fe/Ce oxide-hydroxide and the hydrosulfide, at constant hydrosulfide initial concentration (∼2.130 mmol/L) and pH 9.5(in 100 mmol/L borate + 0.5 mmol/L PDTA, 25oC, 1 atm): () hydrosulfide oxidation and () iron dissolution.](24330_96.png)
) hydrosulfide oxidation and (![Figure 3.5. Plot of log of the reaction rate (R) vs. log of the initial oxide surface area ([A]t=0), for the reaction between the Fe/Ce oxide-hydroxide and the hydrosulfide, at constant hydrosulfide initial concentration (∼2.130 mmol/L) and pH 9.5(in 100 mmol/L borate + 0.5 mmol/L PDTA, 25oC, 1 atm): () hydrosulfide oxidation and () iron dissolution.](24330_97.png)
) iron dissolution.![Figure 3.6. Plot of log of the reaction rate (R) vs. log of the initial hydrosulfide concentration ([HS-]t=0), for the reaction between the Fe/Ce oxide-hydroxide and the hydrosulfide, at constant oxide-hydroxide initial surface area (∼108.9 m2/L) and pH 9.5(in 100 mmol/L borate + 0.5 mmol/L PDTA, 25oC, 1 atm): () hydrosulfide oxidation and () iron dissolution.](24330_99.png)
) hydrosulfide oxidation and (![Figure 3.6. Plot of log of the reaction rate (R) vs. log of the initial hydrosulfide concentration ([HS-]t=0), for the reaction between the Fe/Ce oxide-hydroxide and the hydrosulfide, at constant oxide-hydroxide initial surface area (∼108.9 m2/L) and pH 9.5(in 100 mmol/L borate + 0.5 mmol/L PDTA, 25oC, 1 atm): () hydrosulfide oxidation and () iron dissolution.](24330_100.png)
) iron dissolution.![Figure 3.7. Plot of log of reaction rate (R) vs. log of initial proton concentration ([H+]t=0), for the reaction between Fe/Ce oxide-hydroxide and hydrosulfide, at constant oxide-hydroxide initial surface area (∼108.9 m2/L) and constant hydrosulfide initial concentration (∼2.150 mmol/L)(in 100 mmol/L borate + 0.5 mmol/L PDTA, 25oC, 1 atm): () hydrosulfide oxidation and () iron dissolution.](24330_103.png)
) hydrosulfide oxidation and (![Figure 3.7. Plot of log of reaction rate (R) vs. log of initial proton concentration ([H+]t=0), for the reaction between Fe/Ce oxide-hydroxide and hydrosulfide, at constant oxide-hydroxide initial surface area (∼108.9 m2/L) and constant hydrosulfide initial concentration (∼2.150 mmol/L)(in 100 mmol/L borate + 0.5 mmol/L PDTA, 25oC, 1 atm): () hydrosulfide oxidation and () iron dissolution.](24330_104.png)
) iron dissolution.
) hydrosulfide oxidation and (
) iron dissolution; (b) evolution of hydrosulfide oxidation products: (
) thiosulfate, (
) polysulfides and (
) sulfate. Sx
2-yield = Sx
2-peak surface/initial HS-peak surface.
)pH = 8,(□)pH = 9,(
)pH = 10and (
) pH = 11.
) hydrosulfide oxidation and (
) iron dissolution) compared with HS-solution ((
) hydrosulfide oxidation and (
) iron dissolution); (b) evolution of thiosulfate for (
) HS-+ Sx
2-solution and (
) HS-solution.
) hydrosulfide oxidation and (
) iron dissolution) compared with HS-solution ((
) hydrosulfide oxidation and (
) iron dissolution); (b) evolution of thiosulfate for (
) HS-+ Sx
2-solution and (
) HS-solution.
) hydrosulfide oxidation and (
) iron dissolution) compared with HS-solution ((
) hydrosulfide oxidation and (
) iron dissolution); (b) evolution of oxidation products: SO3
2-+ HS-solution ((
) sulfite, (
) thiosulfate and (
) sulfate) compared with HS-solution ((
) thiosulfate).
) hydrosulfide oxidation, (
) thiosulfate and (
) iron dissolution) compared with HS-solution ((
) hydrosulfide oxidation, (
) thiosulfate and (
) iron dissolution).![Figure 5.1. Effect of pH on hydrosulfide oxidation (filled symbols) and DO2(empty symbols) evolution for the reaction between Fe/CeOx/O2system and hydrosulfide (100 mmol/L borate, 25oC, 1 atm, [A]t=0= 100.9 m2/L): () : oxic (−−) : anoxic () DO2 - pH = 8.5; () : oxic (−−) : anoxic (□) DO2 - pH = 9.5; () : oxic (−−) : anoxic (○) DO2 - pH = 10.5. Dotted lines show trends.](24330_242.png)
) : oxic (−![Figure 5.1. Effect of pH on hydrosulfide oxidation (filled symbols) and DO2(empty symbols) evolution for the reaction between Fe/CeOx/O2system and hydrosulfide (100 mmol/L borate, 25oC, 1 atm, [A]t=0= 100.9 m2/L): () : oxic (−−) : anoxic () DO2 - pH = 8.5; () : oxic (−−) : anoxic (□) DO2 - pH = 9.5; () : oxic (−−) : anoxic (○) DO2 - pH = 10.5. Dotted lines show trends.](24330_243.png)
−) : anoxic () DO2 - pH = 8.5; (![Figure 5.1. Effect of pH on hydrosulfide oxidation (filled symbols) and DO2(empty symbols) evolution for the reaction between Fe/CeOx/O2system and hydrosulfide (100 mmol/L borate, 25oC, 1 atm, [A]t=0= 100.9 m2/L): () : oxic (−−) : anoxic () DO2 - pH = 8.5; () : oxic (−−) : anoxic (□) DO2 - pH = 9.5; () : oxic (−−) : anoxic (○) DO2 - pH = 10.5. Dotted lines show trends.](24330_244.png)
) : oxic (−![Figure 5.1. Effect of pH on hydrosulfide oxidation (filled symbols) and DO2(empty symbols) evolution for the reaction between Fe/CeOx/O2system and hydrosulfide (100 mmol/L borate, 25oC, 1 atm, [A]t=0= 100.9 m2/L): () : oxic (−−) : anoxic () DO2 - pH = 8.5; () : oxic (−−) : anoxic (□) DO2 - pH = 9.5; () : oxic (−−) : anoxic (○) DO2 - pH = 10.5. Dotted lines show trends.](24330_245.png)
−) : anoxic (□) DO2 - pH = 9.5; (![Figure 5.1. Effect of pH on hydrosulfide oxidation (filled symbols) and DO2(empty symbols) evolution for the reaction between Fe/CeOx/O2system and hydrosulfide (100 mmol/L borate, 25oC, 1 atm, [A]t=0= 100.9 m2/L): () : oxic (−−) : anoxic () DO2 - pH = 8.5; () : oxic (−−) : anoxic (□) DO2 - pH = 9.5; () : oxic (−−) : anoxic (○) DO2 - pH = 10.5. Dotted lines show trends.](24330_246.png)
) : oxic (−![Figure 5.1. Effect of pH on hydrosulfide oxidation (filled symbols) and DO2(empty symbols) evolution for the reaction between Fe/CeOx/O2system and hydrosulfide (100 mmol/L borate, 25oC, 1 atm, [A]t=0= 100.9 m2/L): () : oxic (−−) : anoxic () DO2 - pH = 8.5; () : oxic (−−) : anoxic (□) DO2 - pH = 9.5; () : oxic (−−) : anoxic (○) DO2 - pH = 10.5. Dotted lines show trends.](24330_247.png)
−) : anoxic (○) DO2 - pH = 10.5. Dotted lines show trends.
), pH = 9.5 (
), pH = 10.5 (
). S2O3
2-yield = mmol S2O3
2-produced/mmol HS-consumed. Sn
2-= Sn
2-area peak /initial HS-area peak. Conditions as in Figure 5.1. Dotted lines show trends.
) homogeneous HS-oxidation without Fe/CeOx; O2,total(2.45 mmol/L); (∆) anoxic reaction; HS-/Fe/CeOx (100.4 m2/L); (
) oxic reaction; Fe/CeOx (100.6 m2/L) and O2,total(2.45 mmol/L). (a) solid lines represent simulated HS-concentrations using Eq.12 (
); Eq.11 (∆); Eq.13 (
); (b) dotted lines show trends; (c) solid lines represent the sum of S2O3
2-yields from (
) and (
) profiles.
).
) 0.5 mmol/L, (
) 0.7 mmol/L, (Δ) 1 mmol/L and (
) 1.8 mmol/L.
) 100 m2/L, (
) 120 m2/L and (
)140 m2/L.
) pH = 10.5, (
) pH = 11, (
) pH = 11.5 and (
) pH = 12. (*) is taken from reference (10) and represents the dissolved iron during the reaction between Fe/CeOx and HS-in similar conditions. Lines show trends.
) DO2 only (
) Fe/CeOx + DO2;(b) Aerobic reaction betweenFe/CeOx and methyl mercaptide at constant surface area and pH (120 m2/L Fe/CeOx, pH =12): Effect of MM initial concentration on CH3S-conversion (
) 0.5 mmol/L, (□) 1.0 mmol/L, (
) 1.5 mmol/L and (
) 2.0 mmol/L. Lines show trends.
) pH 10.5, (
) pH = 11, (
) pH = 11.5 and (
) pH = 12. Lines show trends.
)ε = 1.1 anda
Fe/CeOx
= 50 m2/L, (
)ε = 5.8 anda
Fe/CeOx
= 50 m2/L, (
)ε = 5.8 anda
Fe/CeOx
= 120 m2/L, (
)ε = 24.2 anda
Fe/CeOx
= 50 m2/L. Lines show trends.
) DO2 only, (
) 50 m2/L FeCeOx, (
) 120 m2/L FeCeOx; (b) Effect of pH on methyl mercaptide (filled symbols) and bisulfide (empty symbols) oxidation by FeCeOx and DO2 (100 mmol/L borate, 120 m2/L FeCeOx,C
0
(MM) = 1 mmol/L,C
0
(HS-) = 0.5 mmol/L): (
) pH 10.5, (
) pH 12. Lines show trends.
) bisulfide only, (
) polysulfides-bisulfide solution.Lines show trends.
) 0.5 mmol/L DMS, (
) 1.0 mmol/L DMS, (
) no DMS.
) Mercaptide oxidation, (
) HS-oxidation and (
) DO2 profile. (
) represents oxidation of HS-by FeCeOx and DO2 in similar conditions but without MM. Lines show trends.
) and Ce (
) oxides.
) Fe/AlOx0.9, (
) FeOx, (
) Fe/MnOx0.9 and (
) Fe/CeOx0.9.
) Fe/CeOx0.1, (
) Fe/CeOx0.5 and (
) Fe/CeOx0.9.
) Fe/MnOx0.1, (
) Fe/MnOx0.5 and (
) Fe/MnOx0.9.
) Fe/AlOx0.9, (
) FeOx, (
) Fe/MnOx0.9 and (
) Fe/CeOx0.9. S2O3
2-yield as in Figure 7.5.
) Fe/CeOx0.1, (
) Fe/CeOx0.5 and (
) Fe/CeOx0.9. S2O3
2-yield as in Figure 7.5.
) Fe/MnOx0.1, (
) Fe/MnOx0.5 and (
) Fe/MnOx0.9. S2O3
2-yield as in Figure 7.5.Liste des tableaux
= electron transfer link between two surface species.© Catalin Florin Petre, 2007
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