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Triantis TM, Fotiou T, Kaloudis T, Kontos AG, Falaras P, Dionysiou DD, Pelaez M, Hiskia A. Photocatalytic degradation and mineralization of microcystin-LR under UV-A, solar and visible light using nanostructured nitrogen doped TiO2. J Hazard Mater 2012; 211-212:196-202. [PMID: 22169146 DOI: 10.1016/j.jhazmat.2011.11.042] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 11/09/2011] [Accepted: 11/12/2011] [Indexed: 05/31/2023]
Abstract
In an attempt to face serious environmental hazards, the degradation of microcystin-LR (MC-LR), one of the most common and more toxic water soluble cyanotoxin compounds released by cyanobacteria blooms, was investigated using nitrogen doped TiO(2) (N-TiO(2)) photocatalyst, under UV-A, solar and visible light. Commercial Degussa P25 TiO(2), Kronos and reference TiO(2) nanopowders were used for comparison. It was found that under UV-A irradiation, all photocatalysts were effective in toxin elimination. The higher MC-LR degradation (99%) was observed with Degussa P25 TiO(2) followed by N-TiO(2) with 96% toxin destruction after 20 min of illumination. Under solar light illumination, N-TiO(2) nanocatalyst exhibits similar photocatalytic activity with that of commercially available materials such as Degussa P25 and Kronos TiO(2) for the destruction of MC-LR. Upon irradiation with visible light Degussa P25 practically did not show any response, while the N-TiO(2) displayed remarkable photocatalytic efficiency. In addition, it has been shown that photodegradation products did not present any significant protein phosphatase inhibition activity, proving that toxicity is proportional only to the remaining MC-LR in solution. Finally, total organic carbon (TOC) and inorganic ions (NO(2)(-), NO(3)(-) and NH(4)(+)) determinations confirmed that complete photocatalytic mineralization of MC-LR was achieved under both UV-A and solar light.
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Affiliation(s)
- T M Triantis
- Laboratory of Catalytic - Photocatalytic Processes (Solar Energy - Environment), Institute of Physical Chemistry, National Center for Scientific Research Demokritos, Neapoleos 25, 15310 Agia Paraskevi, Attiki, Greece
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Antonaraki S, Triantis T, Papaconstantinou E, Hiskia A. Photocatalytic degradation of lindane by polyoxometalates: Intermediates and mechanistic aspects. Catal Today 2010. [DOI: 10.1016/j.cattod.2010.02.017] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Triantis T, Troupis A, Gkika E, Alexakos G, Boukos N, Papaconstantinou E, Hiskia A. Photocatalytic synthesis of Se nanoparticles using polyoxometalates. Catal Today 2009. [DOI: 10.1016/j.cattod.2008.12.028] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Tsimeli K, Triantis T, Dimotikali D, Hiskia A. Development of a rapid and sensitive method for the simultaneous determination of 1,2-dibromoethane, 1,4-dichlorobenzene and naphthalene residues in honey using HS-SPME coupled with GC–MS. Anal Chim Acta 2008; 617:64-71. [DOI: 10.1016/j.aca.2008.03.049] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 03/20/2008] [Accepted: 03/25/2008] [Indexed: 10/22/2022]
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Troupis A, Gkika E, Triantis T, Hiskia A, Papaconstantinou E. Photocatalytic reductive destruction of azo dyes by polyoxometallates: Naphthol blue black. J Photochem Photobiol A Chem 2007. [DOI: 10.1016/j.jphotochem.2006.12.022] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Gkika E, Troupis A, Hiskia A, Papaconstantinou E. Photocatalytic reduction and recovery of mercury by polyoxometalates. Environ Sci Technol 2005; 39:4242-8. [PMID: 15984806 DOI: 10.1021/es0493143] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Photocatalytic reduction of mercury in aqueous solutions using PW12O40(3-) or SiW12O40(4-) as photocatalysts has been studied as a function of irradiation time, concentration of Hg(II), polyoxometalate, and organic substrate in the presence or absence of dioxygen. The photocatalytic cycle starts with irradiation of polyoxometalate, goes through the oxidation of, for instance, propan-2-ol (used as sacrificial reagent), and closes with the reoxidation of reduced polyoxometalate by Hg2+ ions. Mercury(II) is reduced to mercury(I) and finally to Hg(0) giving a dark-gray deposit, following a staged one-by-one electron process and a first-order kinetics in [Hg2+]. The process is slightly more efficient in the absence of dioxygen, while the increase of either catalyst or propan-2-ol concentration results in the augmentation of the rate of reduction till a certain point where it reaches a plateau. The results show that this method is suitable for a great range of mercury concentration from 20 to 800 ppm achieving almost complete recovery of mercury up to nondetected traces (<50 ppb). In addition, this homogeneous process demonstrates advantages such as the lack of necessity for separation of the zero state metal from the catalyst and ensures that the precipitation of metal will not poison the catalyst or hinder its photocatalytic activity.
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Affiliation(s)
- E Gkika
- Institute of Physical Chemistry, NCSR Demokritos, 153 10 Athens, Greece
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Koutsouba V, Heberer T, Fuhrmann B, Schmidt-Baumler K, Tsipi D, Hiskia A. Determination of polar pharmaceuticals in sewage water of Greece by gas chromatography-mass spectrometry. Chemosphere 2003; 51:69-75. [PMID: 12586139 DOI: 10.1016/s0045-6535(02)00819-6] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Sewage influents and effluents of different urban areas of Greece, were analyzed for polar pharmaceutical residues, used in human medicine. Drugs investigated were the anti-inflammatory drugs diclofenac and ibuprofen, the metabolite of the drugs clofibrates used as blood lipid regulators, clofibric acid and the analgesics phenazone and propyphenazone. Analysis was carried out using capillary gas chromatography-mass spectrometry with selected ion monitoring. The method used was involved solid phase extraction (C(18)) and derivatization with pentafluorobenzyl bromide. Diclofenac was detected in every sewage effluent sample.
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Affiliation(s)
- V Koutsouba
- General Chemical State Laboratory, Pesticide Residues Laboratory, An. Tsoha 16, 11521 Athens, Greece
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Abstract
A series of polyoxometalates PW12O40(3-), SiW12O40(4-), and P2Mo18O62(6-) have been used as photocatalysts for recovery of copper and production of fine metal particles. The process involves absorption of light by polyoxometalates, oxidation of an organic substrate, for instance, propan-2-ol as sacrificial reducing reagent, and reoxidation of the reduced polyoxometalates by Cu2+ ions, closing the photocatalytic cycle. Copper(II) ions are reduced to copper(I) and finally to zero-state particles in a 2-electron process, as also suggested by the half-order dependence. Increase of catalyst or propan-2-ol concentration, or both, accelerates the photodeposition of copper until a saturation value is reached. The method is operational at a wide range of copper concentrations varying from 3 to 1300 ppm, leading to very low final concentrations (<0.2 ppm). The presence of dioxygen suppresses the initiation of copper recovery, though the process is equally effective after dioxygen is consumed. The process is independent of pH within the range 0.3-5.0. Addition of ClO4-, NO3-, or CH3COO- has no effect on the removal of copper ions. Chloride ions retard the enhancement of copper precipitation through stabilization of copper(I). This homogeneous, polyoxometalate-based process exhibits some benefits in comparison with the semiconductor-based (heterogeneous) recovery of metals: The final zero-state metal particles are obtained in pure form. No separation from the catalyst is needed, and moreover, the process is catalytic as the photodeposited metal particulates do not hinder the photocatalytic action of polyoxometalate anions.
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Affiliation(s)
- A Troupis
- Institute of Physical Chemistry, NCSR Demokritos, 153 10 Athens, Greece
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Antonaraki S, Androulaki E, Dimotikali D, Hiskia A, Papaconstantinou E. Photolytic degradation of all chlorophenols with polyoxometallates and H2O2. J Photochem Photobiol A Chem 2002. [DOI: 10.1016/s1010-6030(02)00042-4] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Hiskia A, Papaconstantinou E. Photocatalytic oxidation of organic compounds by polyoxometalates of molybdenum and tungsten. Catalyst regeneration by dioxygen. Inorg Chem 2002. [DOI: 10.1021/ic00028a007] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Heberer T, Fuhrmann B, Schmidt-Baumler K, Tsipi D, Koutsouba V, Hiskia A. Occurrence of Pharmaceutical Residues in Sewage, River, Ground, and Drinking Water in Greece and Berlin (Germany). ACTA ACUST UNITED AC 2001. [DOI: 10.1021/bk-2001-0791.ch004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Affiliation(s)
- Th. Heberer
- Institute of Food Chemistry, Technical University of Berlin, Sekr. TIB 4/3-1, Gustav-Meyer-Allee 25,13355 Berlin, Germany
| | - B. Fuhrmann
- Institute of Food Chemistry, Technical University of Berlin, Sekr. TIB 4/3-1, Gustav-Meyer-Allee 25,13355 Berlin, Germany
| | - K. Schmidt-Baumler
- Institute of Food Chemistry, Technical University of Berlin, Sekr. TIB 4/3-1, Gustav-Meyer-Allee 25,13355 Berlin, Germany
| | - D. Tsipi
- General Chemical State Laboratory, 16, An. Tsoha, 11521, Athens, Greece
| | - V. Koutsouba
- General Chemical State Laboratory, 16, An. Tsoha, 11521, Athens, Greece
| | - A. Hiskia
- Institute of Physical Chemistry, NCSR Demokritos, 15310, Athens, Greece
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Hiskia A, Ecke M, Troupis A, Kokorakis A, Hennig H, Papaconstantinou E. Sonolytic, photolytic, and photocatalytic decomposition of atrazine in the presence of polyoxometalates. Environ Sci Technol 2001; 35:2358-2364. [PMID: 11414045 DOI: 10.1021/es000212w] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Aqueous solutions of atrazine [2-chloro-4-(isopropylamino)-6-(ethylamino)-s-triazine] (CIET) decompose upon illumination with a low-pressure Hg-arc lamp (254 nm). However, no decomposition takes place with lambda > 300 nm. On the other hand, addition of polyoxometalates (POM), PW12O40(3-) or SiW12O40(4-), into a solution of atrazine photodecomposes the substrate within a few minutes (cutoff fiter 320 nm). Ultrasound (US) treatment also decomposes aqueous solutions of atrazine within a few minutes. Both methods, sonolysis and photolysis with POM, give common intermediates, namely, 2-hydroxy-4-(isopropylamino)-6-amino-s-triazine (OIET), 2-chloro-4-(isopropylamino)-6-amino-s-triazine (CIAT), 2-chloro-4-amino-6-(ethylamino)-s-triazine (CAET), 2-hydroxy-4,6-diamino-s-triazine (OAAT), and 2-hydroxy-4-hydroxy-6-amino-s-triazine (OOAT) among others. The final products for both methods, US and photolysis with POM, were cyanuric acid (OOOT), NO3-, Cl-, CO2, and H2O. OOOT showed no signs of decomposition by sonication and/or photolysis with POM. It also resisted degradation upon photolysis with plain UV light (254 nm). However, it has been reported to decompose upon photolysis with lambda > 200 nm. Combination of US and photolysis with POM produces only a cumulative effect.
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Affiliation(s)
- A Hiskia
- Institute of Physical Chemistry, NCSR Demokritós, 153-10 Athens, Greece
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Hiskia A, Androulaki E, Mylonas A, Boyatzis S, Dimoticali D, Minero C, Pelizzetti E, Papaconstantinou E. Photocatalytic mineralization of chlorinated organic pollutants in water by polyoxometallates. Determination of intermediates and final degradation products. Res Chem Intermed 2000. [DOI: 10.1163/156856700x00750] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Tsipi D, Triantafyllou M, Hiskia A. Determination of organochlorine pesticide residues in honey, applying solid phase extraction with RP-C18 material. Analyst 1999; 124:473-5. [PMID: 10605876 DOI: 10.1039/a809724k] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, a new clean up method was developed for the routine multiresidue determination of organochlorine pesticide residues in honey. The analytical procedure requires sample extraction with methanol, followed by a clean up step through a C18 Sep-Pak cartridge. Finally, pesticides are eluted with hexane. The determination of organochlorine pesticide residues was performed by capillary gas chromatography with electron capture detection. The mean recoveries of 18 organochlorine pesticides were estimated at various concentrations and found very efficient in most cases. The detection limits were found to be between 0.05 and 0.20 microgram kg-1.
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Affiliation(s)
- D Tsipi
- General Chemical State Laboratory, Pesticide Residues Laboratory, Athens, Greece
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Mylonas A, Hiskia A, Papaconstantinou E. Contribution to water purification using polyoxometalates. Aromatic derivatives, chloroacetic acids. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/s1381-1169(96)00317-2] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Affiliation(s)
- D Tsipi
- General Chemical State Laboratory of Greece, 16 A. Tsoha, GR-115 21, Athens, Greece
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Papaconstantinou E, Ioannidis A, Hiskia A, Argitis P, Dimotikali D, Korres S. Photocatalytic processes by polyoxometalates. Splitting of water. The role of dioxygen. ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf00999635] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Hiskia A, Papaconstantinou E. Thermal and photochemical catalysis by polyoxometallates Regeneration of catalyst by dioxygen. ACTA ACUST UNITED AC 1991. [DOI: 10.1016/s0167-2991(08)62861-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
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