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Registro Completo |
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Biblioteca(s): |
Embrapa Instrumentação. |
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Data corrente: |
13/08/2004 |
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Data da última atualização: |
08/03/2010 |
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Autoria: |
GARBIN, J. R.; MILORI, D. M. B. P.; SIMÕES, M. L.; SILVA, W. T. L. DA; MARTIN-NETO, L. |
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Título: |
Spectroscopical analysis of humic acids influence over the photolysis of aqueous pesticide residues. |
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Ano de publicação: |
2004 |
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Fonte/Imprenta: |
In: INTERNATIONAL MEETING OF INTERNATIONAL HUMIC SUBSTANCES SOCIETY. -- IHSS, 12, São Pedro, SP, 2004. Humic substances and soil and water environment. Abstracts...[São Carlos], SP: Embrapa Instrumentação Agropecuária, 2004. p. 78. |
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Idioma: |
Inglês |
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Conteúdo: |
I. INTRODUCTION
Pesticide residues are nowadays considered the second largest source of drink water contamination and this kind of residue rarely causes fast manifestation of diseases, but it presents a cumulative effect in the organism which can leads to cromossomal damages and carcinogen effects (Dubus et al., 2000, Helmuth et al., 2000). Several alternative methods have been proposed to solve this problem and special attention has been given to the use of UV light to promote the total degradatíon of the residues, because it's a non-selective method that brings the perspective to use sunlight for solving environmental problems (CYTED, 2001). Pesticide photolysis can occur by direct or indirect way (photocatalysis). Titanium dioxide (TiO2), a low cost, stable and non-toxic semiconductor, is the most commonly used photocatalyst which absorbs light around 360 nm, generating hydroxyl radicais (.OH) in the solution, which attack the pesticide molecules starting or accelerating their breakage.
Humic substances (HS) can affect the photolysis and photocatalysis processes once these compounds to show intense absorption bands over UV range and they can quickly react with -OH. However, the entire mechanism of HS influence over pesticides photolysis remain still unknown (Kamiya and Kameyama, 1998 and Westerhoff et al., 1999). So, is necessary a better knowledge of HS effect on the process to use photolysis and photocatalysis by TiO2 for drink water treatment., because HS are naturally presents in lhe aquatic environment.
The purpose of this work was to analyse the influence of different kinds and concentrations of HS over direct photolysis and photocatalysis of pesticides in aqueous solution, under UV-visible radiation (280-480nm). Were used UV-visible absorption and fluorescence emission spectroscopy to measure the pesticides photolysis rate and Electron Paramagnetic Resonance (EPR) spectroscopy measurements to attend the -OH photogeneration by HA during irradiation. MenosI. INTRODUCTION
Pesticide residues are nowadays considered the second largest source of drink water contamination and this kind of residue rarely causes fast manifestation of diseases, but it presents a cumulative effect in the organism which can leads to cromossomal damages and carcinogen effects (Dubus et al., 2000, Helmuth et al., 2000). Several alternative methods have been proposed to solve this problem and special attention has been given to the use of UV light to promote the total degradatíon of the residues, because it's a non-selective method that brings the perspective to use sunlight for solving environmental problems (CYTED, 2001). Pesticide photolysis can occur by direct or indirect way (photocatalysis). Titanium dioxide (TiO2), a low cost, stable and non-toxic semiconductor, is the most commonly used photocatalyst which absorbs light around 360 nm, generating hydroxyl radicais (.OH) in the solution, which attack the pesticide molecules starting or accelerating their breakage.
Humic substances (HS) can affect the photolysis and photocatalysis processes once these compounds to show intense absorption bands over UV range and they can quickly react with -OH. However, the entire mechanism of HS influence over pesticides photolysis remain still unknown (Kamiya and Kameyama, 1998 and Westerhoff et al., 1999). So, is necessary a better knowledge of HS effect on the process to use photolysis and photocatalysis by TiO2 for drink water treatment., because HS are natural... Mostrar Tudo |
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Palavras-Chave: |
hydroxyl radical; Pesticidas; pesticides photolysis. |
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Thesaurus Nal: |
humic acids. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02816naa a2200217 a 4500
001 1028741
005 2010-03-08
008 2004 bl --- 0-- u #d
100 1 $aGARBIN, J. R.
245 $aSpectroscopical analysis of humic acids influence over the photolysis of aqueous pesticide residues.
260 $c2004
520 $aI. INTRODUCTION Pesticide residues are nowadays considered the second largest source of drink water contamination and this kind of residue rarely causes fast manifestation of diseases, but it presents a cumulative effect in the organism which can leads to cromossomal damages and carcinogen effects (Dubus et al., 2000, Helmuth et al., 2000). Several alternative methods have been proposed to solve this problem and special attention has been given to the use of UV light to promote the total degradatíon of the residues, because it's a non-selective method that brings the perspective to use sunlight for solving environmental problems (CYTED, 2001). Pesticide photolysis can occur by direct or indirect way (photocatalysis). Titanium dioxide (TiO2), a low cost, stable and non-toxic semiconductor, is the most commonly used photocatalyst which absorbs light around 360 nm, generating hydroxyl radicais (.OH) in the solution, which attack the pesticide molecules starting or accelerating their breakage. Humic substances (HS) can affect the photolysis and photocatalysis processes once these compounds to show intense absorption bands over UV range and they can quickly react with -OH. However, the entire mechanism of HS influence over pesticides photolysis remain still unknown (Kamiya and Kameyama, 1998 and Westerhoff et al., 1999). So, is necessary a better knowledge of HS effect on the process to use photolysis and photocatalysis by TiO2 for drink water treatment., because HS are naturally presents in lhe aquatic environment. The purpose of this work was to analyse the influence of different kinds and concentrations of HS over direct photolysis and photocatalysis of pesticides in aqueous solution, under UV-visible radiation (280-480nm). Were used UV-visible absorption and fluorescence emission spectroscopy to measure the pesticides photolysis rate and Electron Paramagnetic Resonance (EPR) spectroscopy measurements to attend the -OH photogeneration by HA during irradiation.
650 $ahumic acids
653 $ahydroxyl radical
653 $aPesticidas
653 $apesticides photolysis
700 1 $aMILORI, D. M. B. P.
700 1 $aSIMÕES, M. L.
700 1 $aSILVA, W. T. L. DA
700 1 $aMARTIN-NETO, L.
773 $tIn: INTERNATIONAL MEETING OF INTERNATIONAL HUMIC SUBSTANCES SOCIETY. -- IHSS, 12, São Pedro, SP, 2004. Humic substances and soil and water environment. Abstracts...[São Carlos], SP: Embrapa Instrumentação Agropecuária, 2004. p. 78.
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Registro original: |
Embrapa Instrumentação (CNPDIA) |
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Origem |
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Registro |
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Registro Completo
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Biblioteca(s): |
Embrapa Gado de Corte. |
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Data corrente: |
12/11/2012 |
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Data da última atualização: |
12/11/2012 |
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Autoria: |
SIMIONI, C.; VALLE, C. B. do; RESENDE, R. M. S.; JANK, L. |
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Afiliação: |
Bolsista DCR, CNPq-Fundect-MS; CACILDA BORGES DO VALLE, CNPGC; ROSANGELA MARIA SIMEAO RESENDE, CNPGC; LIANA JANK, CNPGC. |
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Título: |
Viabilização de cruzamentos intraespecíficos no gênero Brachiaria. |
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Ano de publicação: |
2005 |
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Fonte/Imprenta: |
In: JORNADA CIENTÍFICA DA EMBRAPA GADO DE CORTE, 1., 2005, Campo Grande, MS: Embrapa Gado de Corte, 2005. |
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Páginas: |
1 p. |
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Idioma: |
Português |
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Thesagro: |
Brachiaria decumbens. |
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Categoria do assunto: |
-- |
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URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/70027/1/Simionic.pdf
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Marc: |
LEADER 00530naa a2200169 a 4500
001 1939577
005 2012-11-12
008 2005 bl uuuu u00u1 u #d
100 1 $aSIMIONI, C.
245 $aViabilização de cruzamentos intraespecíficos no gênero Brachiaria.
260 $c2005
300 $a1 p.
650 $aBrachiaria decumbens
700 1 $aVALLE, C. B. do
700 1 $aRESENDE, R. M. S.
700 1 $aJANK, L.
773 $tIn: JORNADA CIENTÍFICA DA EMBRAPA GADO DE CORTE, 1., 2005, Campo Grande, MS: Embrapa Gado de Corte, 2005.
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