Mechanistic studies of surface catalyzed H2O2 decomposition and contaminant degradation in the presence of sand

Miller, Christopher M.; Valentine, Richard L.

doi:10.1016/s0043-1354(98)00500-4

Cited by 137 publications

(92 citation statements)

References 33 publications

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“…However the disadvantage of FentonÕs reagent is that the homogeneous catalyst cannot be retained in the process thus causing additional water pollution. A number of researchers (Valentine and Wang, 1998;Miller and Valentine, 1999) with attempt to minimize the leaching of iron ion focused on the efficiency of heterogeneous catalysis for pollutant oxidation. Recently, considering the practical application of the oxidation process, supported iron oxides or granular size solid catalysts, such as graphite and activated carbon, were also studied for their catalytic characteristics (Lucking et al, 1998;Chou and Huang, 1999).…”

Section: Introductionmentioning

confidence: 99%

Catalytic decomposition of hydrogen peroxide and 4-chlorophenol in the presence of modified activated carbons

et al. 2003

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The objective of this research was to examine the heterogeneous catalytic decomposition of H 2 O 2 and 4-chlorophenol (4-CP) in the presence of activated carbons modified with chemical pretreatments. The decomposition of H 2 O 2 was suppressed significantly by the change of surface properties including the decreased pH pzc modified with oxidizing agent and the reduced active sites occupied by the adsorption of 4-CP. The apparent reaction rate of H 2 O 2 decomposition was dominated by the intrinsic reaction rates on the surface of activated carbon rather than the mass transfer rate of H 2 O 2 to the solid surface. By the detection of chloride ion in suspension, the reduction of 4-CP was not only attributed to the advanced adsorption but also the degradation of 4-CP. The catalytic activity toward 4-CP for the activated carbon followed the inverse sequence of the activity toward H 2 O 2 , suggesting that acidic surface functional group could retard the H 2 O 2 loss and reduce the effect of surface scavenging resulting in the increase of the 4-CP degradation efficiency. Few effective radicals were expected to react with 4-CP for the strong effect of surface scavenging, which could explain why the degradation rate of 4-CP observed in this study was so slow and the dechlorination efficiency was independent of the 4-CP concentration in aqueous phase. Results show that the combination of H 2 O 2 and granular activated carbon (GAC) did increase the total removal of 4-CP than that by single GAC adsorption.

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Section: Introductionmentioning

confidence: 99%

Catalytic decomposition of hydrogen peroxide and 4-chlorophenol in the presence of modified activated carbons

et al. 2003

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“…Mass reduction of toluene (20% after 2 h and 31% after 24 h) occurs with the addition of 300 mM H 2 O 2 . These results suggested that toluene destruction may occur via a heterogeneous Fenton reaction (Reaction 25) due to the relatively high level (4.5 wt %) of iron in the soil, in the absence of any added catalyst during the experiment [3]. However, in this case, the decomposition of H 2 O 2 would not be sufficient for complete BTEX destruction or mineralization.…”

Section: Resultsmentioning

confidence: 99%

“…K oc = sorption coefficient for organic carbon [11]; k OH· = second-order reaction rate constant for hydroxyl radical [7]. for reactions 25 through 29 are mineral specific and were estimated for autoclaved Iowa River alluvial sand [3]. .…”

Section: Discussionmentioning

confidence: 99%

“…Its utility as an oxidizing system relies on the formation of hydroxyl radical ( Researchers have investigated the use of Fenton's reagent for in-situ chemical oxidation (ISCO) under a variety of conditions, and Fenton-type reagents are widely applied (e.g., 37 sites among a total of 42 ISCO sites for soils and groundwater) [1][2][3]. Several modifications of Fenton's reagent for groundwater and soil remediation have been investigated.…”

Section: Introductionmentioning

confidence: 99%

“…[1][2][3] However, controlled release of an oxidant into a subsurface environment is an emerging concept relevant to environmental engineering. In particular, the controlled release of oxidants during the application of in-situ oxidation merits investigation.…”

Section: Introductionmentioning

confidence: 99%

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Remediation of Soils and Ground Water Contaminated by Aromatic and Chlorinated Hydrocarbons and Metals

Hua¹,

Rao²,

Lee³

2004

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Prepared in cooperation with the Indiana Department of Transportation and Federal Highway Administration. AbstractMany of the Indiana Department of Transportation (INDOT) sites are contaminated with aromatic hydrocarbons and chlorinated solvents; these contaminants often occur in the form of light non-aqueous phase liquids (LNAPLs) or dense non-aqueous phase liquids (DNAPLs). Considerable effort has recently been focused on developing in-situ technologies for removing or destroying NAPL source zones, and several potentially viable methods have emerged, including in-situ chemical oxidation (ISCO). ISCO has become an attractive remediation option to managers at many contaminated sites. The three oxidants that are most often applied in-situ are hydrogen peroxide (H 2 O 2 ) with iron catalysts, potassium permanganate (KMnO 4 ), and ozone (O 3 ). While each oxidant system has been field demonstrated to be effective in some instances, a clear understanding of these processes is important to the successful implementation of the technology.The primary goal of the laboratory experiments is to evaluate strategies for improving the effectiveness and efficiency of the oxidants as applied to aggressive remediation of source zones containing residual saturations of NAPLs, particularly as applied at INDOT sites. Several novel approaches have been taken to reach the goals of the study. The first approach enhances the application of Fenton's reagent in soil slurry systems, resulting in a better understanding of the magnitude of non-specific oxidant losses relative to consumption by the target compounds. The second approach explores minimizing non-specific losses of the oxidant by introducing the oxidant (KMnO 4 ) in an encapsulated form. Finally, solubility enhancers are examined to enhance the aqueous NAPL concentrations. Significant enhancements in NAPL aqueous concentration will result in corresponding enhancements of the observed oxidation rate.Based on input from INDOT staff, selected sites will be assessed for amenability to remediation via in-situ oxidation. Efforts will be made to choose sites that are representative of a broad range of INDOT needs. Assessment required travel by senior personnel to specific sites to evaluate the nature and extent of contamination. Site visits were also be made by research assistants to collect soil samples for laboratory experiments.17.

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Degradation of MO and H₂O₂ on Cu/γ‐Al₂O₃ pellets in a fixed bed reactor: Kinetics and transport characteristics

et al. 2020

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Pelletized Cu catalysts (Cu/γ-Al 2 O 3) with different diameters (d p = 1.1-4.2 mm) were prepared and examined kinetically for methyl orange (MO) degradation using a fixed bed reactor. A Cu/γ-Al 2 O 3 catalyst (d p = 2.3 mm) exhibited high degradation activity (Conv. MO > 95%) and superior leaching resistance (Cu leaching <0.6 mg/L in 200 hr). Apparent kinetics showed that both MO degradation and H 2 O 2 decomposition were mainly controlled by internal mass transfer. A plug-flow reactor model with masstransfer coefficients was developed, and a modified empirical correlation for external mass transfer (Sh = 1.5Re' 1.10 Sc 0.42) was proposed to accurately describe the species transport from/to the catalyst pellets in the low Reynolds number regime. The model was verified against conversions of pollutants degradation and H 2 O 2 decomposition separately in a fixed bed with relative errors <5% compared with experimental data; thus, it could be used as an effective tool for further design and optimization of reactor configuration and reaction conditions for the continuous catalytic wet peroxide oxidation process.

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Mechanistic studies of surface catalyzed H2O2 decomposition and contaminant degradation in the presence of sand

Cited by 137 publications

References 33 publications

Catalytic decomposition of hydrogen peroxide and 4-chlorophenol in the presence of modified activated carbons

Catalytic decomposition of hydrogen peroxide and 4-chlorophenol in the presence of modified activated carbons

Remediation of Soils and Ground Water Contaminated by Aromatic and Chlorinated Hydrocarbons and Metals

Degradation of MO and H₂O₂ on Cu/γ‐Al₂O₃ pellets in a fixed bed reactor: Kinetics and transport characteristics

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Mechanistic studies of surface catalyzed H2O2 decomposition and contaminant degradation in the presence of sand

Cited by 137 publications

References 33 publications

Catalytic decomposition of hydrogen peroxide and 4-chlorophenol in the presence of modified activated carbons

Catalytic decomposition of hydrogen peroxide and 4-chlorophenol in the presence of modified activated carbons

Remediation of Soils and Ground Water Contaminated by Aromatic and Chlorinated Hydrocarbons and Metals

Degradation of MO and H2O2 on Cu/γ‐Al2O3 pellets in a fixed bed reactor: Kinetics and transport characteristics

Contact Info

Product

Resources

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Degradation of MO and H₂O₂ on Cu/γ‐Al₂O₃ pellets in a fixed bed reactor: Kinetics and transport characteristics