TiO2-photocatalyzed degradation of phenol in saline media: lumped kinetics, intermediates, and acute toxicity

Azevedo, Eduardo Bessa; Neto, Francisco Radler de Aquino; Dezotti, Márcia

doi:10.1016/j.apcatb.2004.06.014

Cited by 59 publications

(57 citation statements)

References 30 publications

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“…In the first case, after ·H abstraction (by any agent capable of H-abstraction, like OH or Cl 2 -radicals, or capable of electron-transfer from deprotonated phenoxide, or by OH addition followed by H 2 O loss), the further addition of Cl 2 · -leads to the formation of "classical" ortho and para orientated monochloroderivatives, in agreement with literature data (Azavedo et al 2004). In the case of chlorophenols, taking into account that hydroxyl function is ortho, para orienting and activating and that -Cl is ortho/ para orienting and deactivating, a further ·H abstraction is possible in o, p-position with respect to the phenolic hydroxyl.…”

Section: Iron Oxidessupporting

confidence: 87%

Role of iron species in the photo-transformation of phenol in artificial and natural seawater

Calza

Massolino

Pelizzetti

et al. 2012

Science of The Total Environment

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The role played by iron oxides (goethite and akaganeite) and iron(II)/(III) species as photosensitizers toward the transformation of organic matter was examined in saline water using phenol as a model molecule. The study was carried out in NaCl 0.7 M solution at pH 8, artificial (ASW) and natural (NSW) seawater, in a device simulating solar light spectrum and intensity. Under When NSW is spiked with phenol and iron oxides, Fe(II) or Fe(III), halophenols production is enhanced. A close analogy exists between Fe(III), Fe(II)/goethite in ASW and NSW products. Different halophenols production in the natural seawater samples depends on Fe(II)/goethite (above all for 3-chlorophenol, 2,3-dichlorophenol and 4-bromophenol formation) and on Fe(III) colloidal species (3-chlorophenol).3

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Section: Iron Oxidessupporting

confidence: 87%

Role of iron species in the photo-transformation of phenol in artificial and natural seawater

Calza

Massolino

Pelizzetti

et al. 2012

Science of The Total Environment

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“…On the other hand, a previous work (Azevedo et al, 2004) has shown that the CSTR with no recycle configuration favors the build up of intermediates (Smith, 1981, Levenspiel, 1987, Fogler, 1999. Therefore, the different degree of interaction between intermediates and salt leads to distinct behaviors.…”

Section: Uv Spectrophotometrymentioning

confidence: 99%

“…Also, the reactor hydrodynamics and the lumped kinetics of the degradation process were determined. In a previous work (Azevedo et al, 2004), our group studied the same chemical system with one main difference: a CSTR (Continuous Stirred Tank Reactor) operated in batch mode was used. In fact, these two systems represent the extremes of the possible configurations that can be used (Levenspiel, 1987).…”

Section: Introductionmentioning

confidence: 99%

TiO2-Photocatalyzed degradation of phenol in saline media in an annular reactor: hydrodynamics, lumped kinetics, intermediates, and acute toxicity

Azevedo

Torres

Neto

et al. 2009

Braz. J. Chem. Eng.

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-The photocatalytic degradation of phenol in aqueous suspensions of TiO 2 under different salt concentrations in an annular reactor has been investigated. In all cases, complete removal of phenol and mineralization degrees above 90% were achieved. The reactor operational parameters were optimized and its hydrodynamics characterized in order to couple mass balance equations with kinetic ones. The photodegradation of the organics followed a Langmuir-Hinshelwood-Hougen-Watson lumped kinetics. From GC/MS analyses, several intermediates formed during oxidation have been identified. The main ones were catechol, hydroquinone, and 3-phenyl-2-propenal, in this order. The formation of negligible concentrations of 4-chlorophenol was observed only in high salinity medium. Acute toxicity was determined by using Artemia sp. as the test organism, which indicated that intermediate products were all less toxic than phenol and a significant abatement of the overall toxicity was accomplished, regardless of the salt concentration.

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“…TiO 2 as a promising semiconductor material has received intense attention for environmental cleaning, water splitting and solar cells due to its low cost, nontoxicity, long-term stability and high oxidative power [1][2][3]. However, TiO 2 used as photocatalyst shows photoactivity only under ultraviolet (UV) light due to its large intrinsic energy band gap (E g = 3.2 eV) [4].…”

Section: Introductionmentioning

confidence: 99%

Structure and composition study of carbon-doped titanium oxide film combined with first principles

et al. 2014

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Carbon-doped titanium oxide (C/Ti-O) films were prepared on Si(100) wafer, stainless steel (type 304) and glass by reactive magnetron sputtering (RMS) using CO 2 gas as carbon and oxygen source under room temperature (RT). X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to analyze structure and composition of the as-prepared C/Ti-O film. It could be observed from XRD that the as-prepared C/Ti-O film contained TiO crystal phase structure. Ti2p XPS spectrum of the as-prepared C/Ti-O film showed that the valences of titanium were made up of Ti 2+ , Ti 3+ and Ti 4+ . C1s XPS spectrum revealed that carbon was doped into titanium oxide based on the existence of the typical Ti-C bond. The optical absorption curve by ultraviolet-visible (UV-Vis) spectrophotometer showed that the C/Ti-O film appeared the remarkable red shift of absorption edge, which contributed to C substitution in O sites in amorphous TiO 2 . Photocatalysis test using methyl orange (MO) as indicator confirmed that the as-prepared C/Ti-O film had photocatalytic activity. Combined with the results of the tests and first-principles calculations, a potential photocatalysis mechanism was proposed.

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TiO2-photocatalyzed degradation of phenol in saline media: lumped kinetics, intermediates, and acute toxicity

Cited by 59 publications

References 30 publications

Role of iron species in the photo-transformation of phenol in artificial and natural seawater

Role of iron species in the photo-transformation of phenol in artificial and natural seawater

TiO2-Photocatalyzed degradation of phenol in saline media in an annular reactor: hydrodynamics, lumped kinetics, intermediates, and acute toxicity

Structure and composition study of carbon-doped titanium oxide film combined with first principles

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