Carbon materials and catalytic wet air oxidation of organic pollutants in wastewater

Stüber, Frank; Font, Josep; Fortuny, A.; Bengoa, Christophe; Eftaxias, A.; Fabregat, Azael

doi:10.1007/s11244-005-2497-1

Cited by 164 publications

(111 citation statements)

References 219 publications

(489 reference statements)

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“…The noncatalytic process operates at high temperatures (200-320 °C) and pressures (20-200 bar), but the process efficiency can be increased under less severe operating temperatures (130-250 °C) and pressures (5-50 bar) by using homogeneous or heterogeneous active catalysts [31]. The problems associated with the leaching of the metals to the liquid phase can be avoided by replacing the catalysts based on noble metals or metal oxides by metal-free carbon materials [60,61].…”

Section: Environmental Catalytic Applicationsmentioning

confidence: 99%

Tuning CNT Properties for Metal-Free Environmental Catalytic Applications

Rocha

Soares

Figueiredo

et al. 2016

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Abstract:The application of carbon nanotubes (CNTs) as metal-free catalysts is a novel approach for heterogeneous liquid phase catalytic systems. Textural and chemical modifications by liquid/gas phase or mechanical treatments, as well as solid state reactions, were successfully applied to obtain carbon nanotubes with different surface functionalities. Oxygen, nitrogen, and sulfur are the most common heteroatoms introduced on the carbon surface. This short-review highlights different routes used to develop metal-free carbon nanotube catalysts with enhanced properties for Advanced Oxidation Processes.

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Section: Environmental Catalytic Applicationsmentioning

confidence: 99%

Tuning CNT Properties for Metal-Free Environmental Catalytic Applications

Rocha

Soares

Figueiredo

et al. 2016

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“…Both gasification carbon residues had high carbon contents, and the specific surface area of carbon residue 1 was also quite high. To put this into context, graphite and carbon black powder, depending on its preparation, have typical specific surface areas of 10 to 300 m 2 g -1 and 100 to 2500 m 2 g -1 , respectively (Stüber et al 2005). For the other three samples, their specific surface areas are quite low; however some pre-treatment methods, for example physical or chemical activation, could be tested to obtain a higher surface area (Ahmadpour and Do 1996).…”

Section: Physical and Chemical Propertiesmentioning

confidence: 99%

Characterization and Utilization Potential of Wood Ash from Combustion Process and Carbon Residue from Gasification Process

2013

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The aim of this research was to study the physical and chemical properties of fly ashes from combustion process and carbon residue from gasification process whilst comparing the results between these two types of solid residues, as well as against literature values. Ashes from the combustion process and carbon residue from gasification process are formed in different conditions, and it can be assumed that they will be best suited to contrasting utilization applications. The most notable differences between these types of solid residues were that the carbon content and loss-on-ignition value was higher for gasification carbon residue, and the liming capacity was higher for combustion ashes. The calculated liming capacity for combustion ashes and the fact that these ashes were strongly alkaline, together with high nutrient concentrations, indicate that combustion ashes can provide a liming effect. As a result, these ashes could potentially be utilized as a soil conditioning agent to substitute for commercial lime. The carbon content in gasification carbon residue was high which indicates, together with high porosity, that carbon residue would be an ideal sorbent and it could also be used as a fuel.

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“…Ambient conditions of temperature and pressure are typical in photocatalysis. In contrast, wet air oxidation (WAO) operates at harsh conditions, which can become milder in the presence of active catalysts (400-523 K, 0.5-5.0 MPa) [5][6][7][8][9][10][11][12][13][14][15]. Several heterogeneous catalysts based on supported or unsupported metal oxides (e.g., Cu, Zn, Mn, Fe, Co, and Bi) and noble metals (e.g., Ru, Pt, Pd and Rh) have been tested in the last four decades for catalytic wet air oxidation (CWAO) [5][6][7][8][9][10][11]13,14].…”

Section: Introductionmentioning

confidence: 99%

“…However, deactivation phenomena are frequent, such as leaching of active metals to the liquid phase. For this reason, metal-free carbon materials have been tested as catalysts in many CWAO applications, including activated carbons [15][16][17][18][19][20][21][22][23][24], carbon xerogels [20,25], multi-walled carbon nanotubes [26][27][28] and carbon foams and fibres enriched with nitrogen [29]. Carbon materials are very versatile catalysts, since their surface chemistry can be easily modified [30] in order to provide adequate active sites for the reaction.…”

Section: Introductionmentioning

confidence: 99%

Degradation of trinitrophenol by sequential catalytic wet air oxidation and solar TiO2 photocatalysis

Katsoni

Gomes

Pastrana‐Martínez

et al. 2011

Chemical Engineering Journal

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a b s t r a c tCatalytic wet air oxidation (CWAO) and solar TiO 2 photocatalysis were investigated as advanced oxidation processes to degrade trinitrophenol (TNP) in model aqueous solutions. An activated carbon (AC) treated with sulphuric acid of different concentrations (5, 10 and 18 M) at two different temperatures (353 and 423 K) was investigated as a metal-free CWAO catalyst, while a commercially available P25 TiO 2 powder was used as a photocatalyst. CWAO experiments were conducted at 448 K, 0.7 MPa oxygen pressure (4.7 MPa of total pressure), 1.3 g L −1 AC loading and 270 mg L −1 TNP concentration, while photocatalytic experiments were conducted at ambient temperature, 1 g L −1 photocatalyst loading, 500-1000 W m irradiance provided by a solar simulator and 32-270 mg L −1 TNP concentration. Treatment efficiency was assessed by measuring the concentrations of TNP and nitrates, total organic carbon (TOC) and biochemical oxygen demand (BOD 5 ). Up to 90% TNP degradation was attained during CWAO over 120 min, from an initial concentration of 270 mg L −1 . For the same TNP concentration, TiO 2 photocatalysis gives only 13% conversion over the same 120 min. However, for TNP concentrations below 144 mg L −1 , photocatalysis can be effectively used: 100 and 80% TNP degradation obtained in 120 min of irradiation for initial TNP concentrations of 64 and 144 mg L −1 , respectively. In this respect, CWAO and photocatalysis were employed sequentially to treat TNP; complete TNP conversion being achieved after 120 min of CWAO followed by 60 min of photocatalysis at 1000 W m −2 irradiance, and this was accompanied by 82% TOC reduction, as well as an increase of BOD 5 /TOC ratio from 0 to 2.28.

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Carbon materials and catalytic wet air oxidation of organic pollutants in wastewater

Cited by 164 publications

References 219 publications

Tuning CNT Properties for Metal-Free Environmental Catalytic Applications

Tuning CNT Properties for Metal-Free Environmental Catalytic Applications

Characterization and Utilization Potential of Wood Ash from Combustion Process and Carbon Residue from Gasification Process

Degradation of trinitrophenol by sequential catalytic wet air oxidation and solar TiO2 photocatalysis

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