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Marta I. Litter
IIIA – Instituto de Investigación e Ingeniería Ambiental, CONICET, Universidad de San Martín, Campus Miguelete, Av. 25 de Mayo y Francia, 1650, San Martín, Prov. de Buenos Aires, Argentina

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Journal article
Published: 20 July 2021 in Journal of Materials Research and Technology
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Diffraction patterns of polyacrylic acid (PAA) encapsulated-(Fe)-modified ZnAl hydrotalcite (ZnAlH) showed the integration of Fe in the H lattice, resulting in a hybrid nanocomposite (Fe-PAA-ZnAlH), which was mainly verified with the characteristic shift in the 59-63 ° (2θ) region of the ZnAlH (110) reflection plane. The rise in the unit cell parameters (c and a) as the Fe % incremented, denoted incorporation of Fe in the ZnAlH red. Nonetheless, changes in the immobilizer molecular weight (PAA MW) from 1250 kDa to 5.1 kDa did not cause a difference in the distance between layers (c parameter) but in the cation-cation separation (a parameter), which meant that the nanoparticle was not located between layers, but in the lattice. The resulting band gap energies of the calcined hybrid nanocomposites were among 1.07-1.21 eV, which is an additional support of Fe+3 integration, suggesting insertion of Fe+3 3d orbitals between the valence and the conduction band of ZnO. Furthermore, nZVI were prepared through a pre-agglomeration reduction method, where COOH- groups were bound to metal cations. Initially, aqueous Fe+2 was bound to PAA [Fe+2-PAA], then reduced to obtain enclosed hybrid (nZVI-PAA). Less stability and more aggregation were observed with the lower molecular weight PAA. Additionally, PAA dissociation caused by pH changes affected the clustering of the nZVI particles. At higher MW, the hydrodynamic diameter and size distribution become smaller and tighter, respectively, allowing a more monodispersed population with sphere shape and organized in core-shell beads chains.

ACS Style

Sorelis Nieto-Zambrano; Esthela Ramos-Ramίrez; Francisco Tzompantzi Morales; Daria Camilla Boffito; Rafik Naccache; Norma L. Gutiérrez Ortega; Marta I. Litter; Sandra Cipagauta-Dίaz; Aida Liliana Barbosa-López. ZnAl hydrotalcites modified with nanocomposites nZVI–PAA for environmental remediation. Journal of Materials Research and Technology 2021, 14, 2243 -2256.

AMA Style

Sorelis Nieto-Zambrano, Esthela Ramos-Ramίrez, Francisco Tzompantzi Morales, Daria Camilla Boffito, Rafik Naccache, Norma L. Gutiérrez Ortega, Marta I. Litter, Sandra Cipagauta-Dίaz, Aida Liliana Barbosa-López. ZnAl hydrotalcites modified with nanocomposites nZVI–PAA for environmental remediation. Journal of Materials Research and Technology. 2021; 14 ():2243-2256.

Chicago/Turabian Style

Sorelis Nieto-Zambrano; Esthela Ramos-Ramίrez; Francisco Tzompantzi Morales; Daria Camilla Boffito; Rafik Naccache; Norma L. Gutiérrez Ortega; Marta I. Litter; Sandra Cipagauta-Dίaz; Aida Liliana Barbosa-López. 2021. "ZnAl hydrotalcites modified with nanocomposites nZVI–PAA for environmental remediation." Journal of Materials Research and Technology 14, no. : 2243-2256.

Journal article
Published: 29 June 2021 in Journal of Photocatalysis
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Background: Thiomersal (TM), a complex between 2-mercaptobenzoic acid (2-MBA) and ethylmercury (C2H5Hg+), is an antimicrobial preservative used in immunological, ophthalmic, cosmetic products, and vaccines. Objective: TM has been treated by UV/TiO2 photocatalysis in the presence or absence of oxygen at acidic pH. C2H5Hg+, 2-MBA, and 2-sulfobenzoic acid (2-SBA) were found as products. A 2-SBA photocatalytic treatment was undertaken to study sulfur evolution. Methods: Photocatalytic runs were performed using a UVA lamp (λmax = 352 nm), open to the air or under N2. A suspension of the corresponding TM or 2-SBA salt and TiO2 was prepared, and pH was adjusted. Suspensions were stirred in the dark for 30 min and then irradiated. TM, 2-MBA, 2-SBA, and C2H5Hg+ were quantified by HPLC, sulfur by TXRF, and the deposits on the photocatalyst were analyzed by chemical reactions. The mineralization degree was followed by TOC. Sulfate was determined using BaCl2 at 580 nm. Results: Photocatalytic destruction of TM and total C2H5Hg+ was complete under N2 and air, but TM degradation was much faster in air. The evolution of TM and the products followed a pseudo-first-order kinetics. Conclusion: TiO2-photocatalytic degradation is a suitable technique for the treatment of TM and its degradation products. In contrast to other organomercurial compounds, TM degradation is faster in the presence of O2, indicating that the oxidative mechanism is the preferred pathway. A significant TM mineralization (> 60%, NPOC and total S) was obtained. TM was more easily degraded than 2-SBA. Sulfate was the final product.

ACS Style

Emmanuel M. de la Fournière; Jorge M. Meichtry; Graciela S. Custo; Eduardo A. Gautier; Marta I. Litter. New insights on the UV/TiO2 photocatalytic treatment of thiomersal and its 2-sulfobenzoic acid product. Journal of Photocatalysis 2021, 02, 1 -1.

AMA Style

Emmanuel M. de la Fournière, Jorge M. Meichtry, Graciela S. Custo, Eduardo A. Gautier, Marta I. Litter. New insights on the UV/TiO2 photocatalytic treatment of thiomersal and its 2-sulfobenzoic acid product. Journal of Photocatalysis. 2021; 02 ():1-1.

Chicago/Turabian Style

Emmanuel M. de la Fournière; Jorge M. Meichtry; Graciela S. Custo; Eduardo A. Gautier; Marta I. Litter. 2021. "New insights on the UV/TiO2 photocatalytic treatment of thiomersal and its 2-sulfobenzoic acid product." Journal of Photocatalysis 02, no. : 1-1.

Journal article
Published: 13 February 2021 in Journal of Photochemistry and Photobiology A: Chemistry
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Ethylmercury chloride (C2H5HgCl) was treated by UV/TiO2 photocatalysis in the presence of O2 and under N2 at pH 4.2. No report exists on C2H5Hg+ degradation by heterogeneous photocatalysis. The adsorption of C2H5Hg+ over TiO2 (no irradiation) was studied and fitted to the Freundlich isotherm. The photocatalytic evolution of C2H5Hg+ was adjusted to a two parameter Langmuir-Hinshelwood model, modified to include a third parameter attributed to the deactivation caused by the deposition of Hg(0). Hg(II) in solution, Hg(0) and Hg2Cl2 (detected only under N2) were the products of the photocatalytic degradation; the organic moiety was degraded but no organic by-product could be detected. Experiments in the absence of O2 showed a higher conversion rate, indicating that C2H5Hg+ is removed both by oxidative and reductive pathways, being this last step partially inhibited by O2. A degradation mechanism considering both oxidative and reductive one-electron transfer steps is proposed.

ACS Style

Emmanuel M. de la Fournière; Jorge M. Meichtry; Eduardo A. Gautier; Ana G. Leyva; Marta I. Litter. Treatment of ethylmercury chloride by heterogeneous photocatalysis with TiO2. Journal of Photochemistry and Photobiology A: Chemistry 2021, 411, 113205 .

AMA Style

Emmanuel M. de la Fournière, Jorge M. Meichtry, Eduardo A. Gautier, Ana G. Leyva, Marta I. Litter. Treatment of ethylmercury chloride by heterogeneous photocatalysis with TiO2. Journal of Photochemistry and Photobiology A: Chemistry. 2021; 411 ():113205.

Chicago/Turabian Style

Emmanuel M. de la Fournière; Jorge M. Meichtry; Eduardo A. Gautier; Ana G. Leyva; Marta I. Litter. 2021. "Treatment of ethylmercury chloride by heterogeneous photocatalysis with TiO2." Journal of Photochemistry and Photobiology A: Chemistry 411, no. : 113205.

Invited review
Published: 11 July 2020 in Critical Reviews in Environmental Science and Technology
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Today (year 2020), the globally recognized problem of arsenic (As) contamination of water resources and other environments at toxic levels has been reported in all of the 20 Latin American countries. The present review indicates that As is prevalent in 200 areas across these countries. Arsenic is naturally released into the environment and mobilized from geogenic sources comprising: (i) volcanic rocks and emissions, the latter being transported over thousands of kilometers from the source, (ii) metallic mineral deposits, which get exposed to human beings and livestock through drinking water or food chain, and (iii) As-rich geothermal fluids ascending from deep geothermal reservoirs contaminate freshwater sources. The challenge for mitigation is increased manifold by mining and related activities, as As from mining sites is transported by rivers over long distances and even reaches and contaminates coastal environments. The recognition of the As problem by the authorities in several countries has led to various actions for remediation, but there is a lack of long-term strategies for such interventions. Often only total As concentration is reported, while data on As sources, mobilization, speciation, mobility and pathways are lacking which is imperative for assessing quality of any water source, i.e. public and private.

ACS Style

Jochen Bundschuh; Maria Aurora Armienta; Nury Morales-Simfors; Mohammad Ayaz Alam; Dina L. López; Valeria Delgado Quezada; Sebastian Dietrich; Jerusa Schneider; Joseline Tapia; Ondra Sracek; Elianna Castillo; Lue-Meru Marco Parra; Maximina Altamirano Espinoza; Luiz Roberto Guimarães Guilherme; Numa Nahuel Sosa; Nabeel Khan Niazi; Barbara Tomaszewska; Katherine Lizama Allende; Klaus Bieger; David L. Alonso; Pedro F. B. Brandão; Prosun Bhattacharya; Marta I. Litter; Arslan Ahmad. Arsenic in Latin America: New findings on source, mobilization and mobility in human environments in 20 countries based on decadal research 2010-2020. Critical Reviews in Environmental Science and Technology 2020, 51, 1727 -1865.

AMA Style

Jochen Bundschuh, Maria Aurora Armienta, Nury Morales-Simfors, Mohammad Ayaz Alam, Dina L. López, Valeria Delgado Quezada, Sebastian Dietrich, Jerusa Schneider, Joseline Tapia, Ondra Sracek, Elianna Castillo, Lue-Meru Marco Parra, Maximina Altamirano Espinoza, Luiz Roberto Guimarães Guilherme, Numa Nahuel Sosa, Nabeel Khan Niazi, Barbara Tomaszewska, Katherine Lizama Allende, Klaus Bieger, David L. Alonso, Pedro F. B. Brandão, Prosun Bhattacharya, Marta I. Litter, Arslan Ahmad. Arsenic in Latin America: New findings on source, mobilization and mobility in human environments in 20 countries based on decadal research 2010-2020. Critical Reviews in Environmental Science and Technology. 2020; 51 (16):1727-1865.

Chicago/Turabian Style

Jochen Bundschuh; Maria Aurora Armienta; Nury Morales-Simfors; Mohammad Ayaz Alam; Dina L. López; Valeria Delgado Quezada; Sebastian Dietrich; Jerusa Schneider; Joseline Tapia; Ondra Sracek; Elianna Castillo; Lue-Meru Marco Parra; Maximina Altamirano Espinoza; Luiz Roberto Guimarães Guilherme; Numa Nahuel Sosa; Nabeel Khan Niazi; Barbara Tomaszewska; Katherine Lizama Allende; Klaus Bieger; David L. Alonso; Pedro F. B. Brandão; Prosun Bhattacharya; Marta I. Litter; Arslan Ahmad. 2020. "Arsenic in Latin America: New findings on source, mobilization and mobility in human environments in 20 countries based on decadal research 2010-2020." Critical Reviews in Environmental Science and Technology 51, no. 16: 1727-1865.

Journal article
Published: 07 July 2020 in Chemosphere
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The sonochemical (850 kHz) Cr(VI) reduction (0.30 mM, pH 2) in the presence of citric acid (Cit, 2 mM) was analyzed under different working atmospheres: reactor open to air without sparging (ROAWS), and Ar, O2, air and N2 sparging. Hydrogen peroxide formation in pure water at pH 2 and KI dosimetry were also measured. Zero-order kinetics was observed in all cases. A complete Cr(VI) reduction after 180 min insonation was obtained with the ROAWS and under Ar, while a lower Cr(VI) reduction efficiency was achieved under the other conditions. The Cr(VI) reduction and H2O2 formation rates followed the order ROAWS ≅ Ar > air ≅ O2 ≫ N2, while for KI dosimetry the order was ROAWS ≫ O2 ≅ air > Ar ≫ N2. This indicates that H2O2 formation rate is a better measure of the system reactivity for Cr(VI) reduction. For air, O2 and N2, once the sparging was stopped, Cr(VI) reduction rate increased up to approximately the same value obtained for the ROAWS, suggesting that the sparging decreased the generation of reactive species and, thus, the Cr(VI) reduction rate. Nitrate production was measured at low concentrations (micromolar range) in the ROAWS, air and N2 systems. Formic and acetic acids were detected as Cit degradation products. Reaction mechanisms were proposed. It can be concluded that the best condition for Cr(VI) removal is with the ROAWS because of a higher Cr(VI) reduction rate, no atmosphere control is required, and it is a less expensive system.

ACS Style

Jorge M. Meichtry; Lucía Cancelada; Hugo Destaillats; Marta I. Litter. Effect of different gases on the sonochemical Cr(VI) reduction in the presence of citric acid. Chemosphere 2020, 260, 127211 .

AMA Style

Jorge M. Meichtry, Lucía Cancelada, Hugo Destaillats, Marta I. Litter. Effect of different gases on the sonochemical Cr(VI) reduction in the presence of citric acid. Chemosphere. 2020; 260 ():127211.

Chicago/Turabian Style

Jorge M. Meichtry; Lucía Cancelada; Hugo Destaillats; Marta I. Litter. 2020. "Effect of different gases on the sonochemical Cr(VI) reduction in the presence of citric acid." Chemosphere 260, no. : 127211.

Article
Published: 09 March 2020 in International Journal of Applied Ceramic Technology
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Transparent glass sponges are a new class of materials that can potentially be used for effective light distribution in photocatalytic applications. In this work, transparent glass sponges are prepared by the polymer replica technique and coated with TiO2 to obtain a highly efficient photocatalytic material. Necessary conditions for obtaining transparent open‐celled glass sponges are presented. The structure is characterized by employing light microscopy and scanning electron microscopy. In addition, μ ‐ computer tomography (μ‐CT) volume image analysis was performed that allows the calculation of geometrical parameters like pore size and specific surface area (SSA) of the structure, required for application of the new material. For photocatalytic application, the sponges have been coated with titanium dioxide (TiO2) by immersion in a suspension of TiO2 nanoparticles. The activity of the resulting coatings has been tested with the model reaction of transformation of Cr(VI) to Cr(III) in aqueous solutions in the presence of EDTA at pH 2. The reaction kinetics could be adjusted to a pseudo‐first order reaction and the obtained rate constants have been employed to evaluate the photocatalytic activity. The activity of the sponges has been compared with that of samples of glass plates coated with TiO2; it has been found that the sponges exhibited a higher catalytic activity than the glass plates. The photocatalytic activity increased with the porosity of the sponges, and the optimum sample was determined based on its photocatalytic performance and its mechanical stability. The results are promissory for application in photoreactors for transformation of pollutants in water and air decontamination.

ACS Style

Frank B. Löffler; Fabian J. Altermann; Ethel C. Bucharsky; Karl G. Schell; Maria L. Vera; Hernan Traid; Anabela Dwojak; Marta I. Litter. Morphological characterization and photocatalytic efficiency measurements of pure silica transparent open‐cell sponges coated with TiO 2. International Journal of Applied Ceramic Technology 2020, 17, 1930 -1939.

AMA Style

Frank B. Löffler, Fabian J. Altermann, Ethel C. Bucharsky, Karl G. Schell, Maria L. Vera, Hernan Traid, Anabela Dwojak, Marta I. Litter. Morphological characterization and photocatalytic efficiency measurements of pure silica transparent open‐cell sponges coated with TiO 2. International Journal of Applied Ceramic Technology. 2020; 17 (4):1930-1939.

Chicago/Turabian Style

Frank B. Löffler; Fabian J. Altermann; Ethel C. Bucharsky; Karl G. Schell; Maria L. Vera; Hernan Traid; Anabela Dwojak; Marta I. Litter. 2020. "Morphological characterization and photocatalytic efficiency measurements of pure silica transparent open‐cell sponges coated with TiO 2." International Journal of Applied Ceramic Technology 17, no. 4: 1930-1939.

Chapter
Published: 18 January 2020 in Applied Environmental Science and Engineering for a Sustainable Future
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Chemical oxidation and advanced oxidation technologies are important processes for the abatement of refractory and/or toxic pollutants in wastewaters. The species participating in advanced oxidation technologies are powerful radicals, such as the hydroxyl radical, HO•, which can attack virtually all organic compounds at very high reaction rates. In this chapter, oxidative technologies, such as permanganate, ozonation, Fenton and related processes, electrochemical oxidation, γ-radiolysis and electron-beam treatment, nonthermal plasma, persulfate, wet air oxidation, supercritical water oxidation, ultrasound, zero-valent iron, ferrate, water photolysis under vacuum ultraviolet, periodate, chlorine and heterogeneous photocatalysis, some of them combined with UV light, are briefly described, together with examples of their applications. The most important and recent papers are cited together with review papers. These oxidative technologies can process wastewaters resistant to conventional treatments and are complementary to them.

ACS Style

Marta I. Litter. Introduction to Oxidative Technologies for Water Treatment. Applied Environmental Science and Engineering for a Sustainable Future 2020, 119 -175.

AMA Style

Marta I. Litter. Introduction to Oxidative Technologies for Water Treatment. Applied Environmental Science and Engineering for a Sustainable Future. 2020; ():119-175.

Chicago/Turabian Style

Marta I. Litter. 2020. "Introduction to Oxidative Technologies for Water Treatment." Applied Environmental Science and Engineering for a Sustainable Future , no. : 119-175.

Journal article
Published: 27 June 2019 in Science of The Total Environment
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An overview about the presence of arsenic (As) in groundwaters of Argentina, made by a transdisciplinary group of experts is presented. In this second part, the conventional and emerging technologies for As removal, management of wastes, and the initial investment costs of the proposed technologies, with emphasis on developments of local groups are described. Successful examples of real application of conventional and emerging technologies for As removal in waters for human consumption, for medium, small and rural and periurban communities are reported. In the country, the two most applied technologies for arsenic removal at a real scale are reverse osmosis and coagulation-adsorption-filtration processes using iron or aluminum salts or polyelectrolytes as coagulants. A decision tree to evaluate the possible technologies to be applied, based on the population size, the quality of the water and its intended use, is presented, including preliminary and indicative investment costs. Finally, a section discussing the treatment and final disposal of the liquid, semiliquid and solid wastes, generated by the application of the most used technologies is included. Conclusions and recommendations, especially for isolated rural and periurban regions, have been added.

ACS Style

Marta I. Litter; Ana M. Ingallinella; Valentina Olmos; Marianela Savio; Gonzalo Difeo; Lía Botto; Elsa Mónica Farfán Torres; Sergio Taylor; Sofía Frangie; Jorge Herkovits; Isidoro Schalamuk; María José González; Eliana Berardozzi; Fernando S. García Einschlag; Prosun Bhattacharya; Arslan Ahmad. Arsenic in Argentina: Technologies for arsenic removal from groundwater sources, investment costs and waste management practices. Science of The Total Environment 2019, 690, 778 -789.

AMA Style

Marta I. Litter, Ana M. Ingallinella, Valentina Olmos, Marianela Savio, Gonzalo Difeo, Lía Botto, Elsa Mónica Farfán Torres, Sergio Taylor, Sofía Frangie, Jorge Herkovits, Isidoro Schalamuk, María José González, Eliana Berardozzi, Fernando S. García Einschlag, Prosun Bhattacharya, Arslan Ahmad. Arsenic in Argentina: Technologies for arsenic removal from groundwater sources, investment costs and waste management practices. Science of The Total Environment. 2019; 690 ():778-789.

Chicago/Turabian Style

Marta I. Litter; Ana M. Ingallinella; Valentina Olmos; Marianela Savio; Gonzalo Difeo; Lía Botto; Elsa Mónica Farfán Torres; Sergio Taylor; Sofía Frangie; Jorge Herkovits; Isidoro Schalamuk; María José González; Eliana Berardozzi; Fernando S. García Einschlag; Prosun Bhattacharya; Arslan Ahmad. 2019. "Arsenic in Argentina: Technologies for arsenic removal from groundwater sources, investment costs and waste management practices." Science of The Total Environment 690, no. : 778-789.

Journal article
Published: 22 April 2019 in Science of The Total Environment
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An overview about the presence of arsenic (As) in groundwaters of Argentina, made by a transdisciplinary group of experts is presented. Aspects on As occurrence, effects of As on human health, regulations regarding the maximum allowable amount of As in drinking water as well as bottled water, and analytical techniques for As determination are presented. The most affected region in Argentina is the Chaco-Pampean plain, covering around 10 million km2, where approximately 88% of 86 groundwater samples collected in 2007 exceeded the World Health Organization (WHO) guideline value. In the Salí river basin, As concentrations ranged from 11.4 to 1660 μg/L, with 100% of the samples above the WHO guideline value. In the Argentine Altiplano (Puna) and Subandean valleys, 61% of 62 samples collected from surface and groundwaters exceeded the WHO limit. Thus, it can be estimated that, at present, the population at risk in Argentina reaches around four million people. Pathologies derived from the chronic consumption of As, the metabolism of As in the human body and the effects of the different As chemical forms, gathered under the name HACRE (hidroarsenicismo crónico regional endémico in Spanish, for chronic regional endemic hydroarsenicism) are described. Regarding the regulations, the 10 μg/L limit recommended by the WHO and the United States Environmental Protection Agency has been incorporated in the Argentine Food Code, but the application is still on hold. In addition, there is disparity regarding the maximal admitted values in several provinces. Considerations about the As concentrations in bottled water are also presented. A survey indicates that there are several Argentine laboratories with the suitable equipment for As determination at 10 μg/L, although the 66% of them are concentrated in Buenos Aires City, and in the Santa Fe, Córdoba and Buenos Aires provinces. Conclusions and recommendations of this first part are provided.

ACS Style

Marta I. Litter; Ana M. Ingallinella; Valentina Olmos; Marianela Savio; Gonzalo Difeo; Lía Botto; Elsa Mónica Farfán Torres; Sergio Taylor; Sofía Frangie; Jorge Herkovits; Isidoro Schalamuk; María José González; Eliana Berardozzi; Fernando S. García Einschlag; Prosun Bhattacharya; Arslan Ahmad. Arsenic in Argentina: Occurrence, human health, legislation and determination. Science of The Total Environment 2019, 676, 756 -766.

AMA Style

Marta I. Litter, Ana M. Ingallinella, Valentina Olmos, Marianela Savio, Gonzalo Difeo, Lía Botto, Elsa Mónica Farfán Torres, Sergio Taylor, Sofía Frangie, Jorge Herkovits, Isidoro Schalamuk, María José González, Eliana Berardozzi, Fernando S. García Einschlag, Prosun Bhattacharya, Arslan Ahmad. Arsenic in Argentina: Occurrence, human health, legislation and determination. Science of The Total Environment. 2019; 676 ():756-766.

Chicago/Turabian Style

Marta I. Litter; Ana M. Ingallinella; Valentina Olmos; Marianela Savio; Gonzalo Difeo; Lía Botto; Elsa Mónica Farfán Torres; Sergio Taylor; Sofía Frangie; Jorge Herkovits; Isidoro Schalamuk; María José González; Eliana Berardozzi; Fernando S. García Einschlag; Prosun Bhattacharya; Arslan Ahmad. 2019. "Arsenic in Argentina: Occurrence, human health, legislation and determination." Science of The Total Environment 676, no. : 756-766.

Journal article
Published: 01 April 2019 in Journal of Environmental Management
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Iron-based nanoparticles were synthesized by a rapid method at room temperature using yerba mate (YM) extracts with FeCl3 in different proportions. Materials prepared from green tea (GT) extracts were also synthesized for comparison. These materials were thoroughly characterized by chemical analyses, XRD, magnetization, SEM-EDS, TEM-SAED, FTIR, UV-Vis, Raman, Mössbauer and XANES spectroscopies, and BET area analysis. It was concluded that the products are nonmagnetic iron complexes of the components of the extracts. The applicability of the materials for Cr(VI) (300 μM) removal from aqueous solutions at pH 3 using two Cr(VI):Fe molar ratios (MR), 1:3 and 1:0.5, has been tested. At Cr(VI):Fe MR = 1:3, the best YM materials gave complete Cr(VI) removal after two minutes of contact, similar to that obtained with commercial nanoscale zerovalent iron (N25), with dissolved Fe(II), and with a likewise prepared GT material. At a lower Cr(VI):Fe MR (1:0.5), although Cr(VI) removal was not complete after 20 min of reaction, the YM nanoparticles were more efficient than N25, GT nanoparticles and Fe(II) in solution. The results suggest that an optimal Cr(VI):Fe MR ratio could be reached when using the new YM nanoparticles, able to achieve a complete Cr(VI) reduction, and leaving very low Cr and Fe concentrations in the treated solutions. The rapid preparation of the nanoparticles would allow their use in removal of pollutants in soils and groundwater by direct injection of the mixture of precursors.

ACS Style

Fabiana E. García; Alejandro M. Senn; Jorge M. Meichtry; Thomas B. Scott; Huw Pullin; Ana G. Leyva; Emilia B. Halac; Cinthia P. Ramos; Joaquín Sacanell; M. Mizrahi; Félix G. Requejo; Marta I. Litter. Iron-based nanoparticles prepared from yerba mate extract. Synthesis, characterization and use on chromium removal. Journal of Environmental Management 2019, 235, 1 -8.

AMA Style

Fabiana E. García, Alejandro M. Senn, Jorge M. Meichtry, Thomas B. Scott, Huw Pullin, Ana G. Leyva, Emilia B. Halac, Cinthia P. Ramos, Joaquín Sacanell, M. Mizrahi, Félix G. Requejo, Marta I. Litter. Iron-based nanoparticles prepared from yerba mate extract. Synthesis, characterization and use on chromium removal. Journal of Environmental Management. 2019; 235 ():1-8.

Chicago/Turabian Style

Fabiana E. García; Alejandro M. Senn; Jorge M. Meichtry; Thomas B. Scott; Huw Pullin; Ana G. Leyva; Emilia B. Halac; Cinthia P. Ramos; Joaquín Sacanell; M. Mizrahi; Félix G. Requejo; Marta I. Litter. 2019. "Iron-based nanoparticles prepared from yerba mate extract. Synthesis, characterization and use on chromium removal." Journal of Environmental Management 235, no. : 1-8.

Journal article
Published: 22 September 2018 in Applied Catalysis B: Environmental
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Hematite nanoparticles (nHm) were tested for Cr(VI) photocatalytic reduction (300 µM) in the presence of different electron donors such as citrate (Cit), oxalate (Ox), 2-propanol and methanol. At pH 3 and under irradiation at λ ≥ 310 nm, almost negligible reaction took place in the absence of donor or with the alcohols, while the reduction was very rapid in the presence of Cit (less than 25 min), and faster with Ox (15 min). Homogeneous experiments with FeCl3 instead of nHm showed a complete Cr(VI) reduction in the presence of both complexing agents in less than 10 min. Under irradiation at λ > 495 nm and with nHm at pH 3, a good Cr(VI) transformation took place with both donors, but at a considerably lower rate than under UV light (around 100% at 180 min), the decay being negligible in the homogeneous systems with Fe(III). Under irradiation at λ > 610 nm, no Cr(VI) transformation took place over nHm. Experiments at pH 6 under UV-Vis light with Cit in the presence of nHm gave a good Cr(VI) decay, faster with Fe(III) (60% and 90% in 105 min, respectively); some Cr(VI) transformation (around 35% in 180 min) was found with Cit under Vis light. Interestingly, at both wavelength ranges, the reaction was negligible when Ox was used. Mechanisms taking place under the different conditions were proposed, including the role of surface charge transfer complexes on nHm.

ACS Style

Imme Kretschmer; Alejandro M. Senn; J. Martín Meichtry; Graciela Custo; Emilia B. Halac; Ralf Dillert; Detlef W. Bahnemann; Marta I. Litter. Photocatalytic reduction of Cr(VI) on hematite nanoparticles in the presence of oxalate and citrate. Applied Catalysis B: Environmental 2018, 242, 218 -226.

AMA Style

Imme Kretschmer, Alejandro M. Senn, J. Martín Meichtry, Graciela Custo, Emilia B. Halac, Ralf Dillert, Detlef W. Bahnemann, Marta I. Litter. Photocatalytic reduction of Cr(VI) on hematite nanoparticles in the presence of oxalate and citrate. Applied Catalysis B: Environmental. 2018; 242 ():218-226.

Chicago/Turabian Style

Imme Kretschmer; Alejandro M. Senn; J. Martín Meichtry; Graciela Custo; Emilia B. Halac; Ralf Dillert; Detlef W. Bahnemann; Marta I. Litter. 2018. "Photocatalytic reduction of Cr(VI) on hematite nanoparticles in the presence of oxalate and citrate." Applied Catalysis B: Environmental 242, no. : 218-226.

Articles
Published: 19 July 2018 in Matéria (Rio de Janeiro)
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RESUMEN El TiO2 es un semiconductor ampliamente utilizado en el proceso de fotocatálisis heterogénea para la descontaminación de aguas. Diversos estudios indican que las estructuras ordenadas de nanotubos en fase anatasa mejoran las propiedades fotocatalíticas del material con respecto a otras morfologías y estructuras de TiO2. El objetivo del presente trabajo es evaluar la influencia de diferentes tratamientos térmicos sobre la integridad y estructura cristalina de recubrimientos nanotubulares de TiO2 obtenidos mediante la técnica de oxidación anódica. Para la oxidación se utilizó como electrolito una solución de 0,6% p/p de fluoruro de amonio y 3,5% p/p de agua en etilenglicol. Se hizo circular corriente continua a un voltaje constante de 45 V durante 2 h. Luego de la oxidación anódica, se realizaron tratamientos térmicos de 2 h y 4 h a 450, 550 y 650 °C, con rampa de calentamiento de 10 ºC/min. Se caracterizó la morfología y la estructura cristalina de los recubrimientos mediante microscopía electrónica de barrido y difracción de rayos X, respectivamente. Se obtuvieron recubrimientos nanotubulares de TiO2 de 85 nm de diámetro interior, 18 nm de espesor de pared y 7 ?m de longitud (valores promedio), que mantuvieron su integridad estructural sin cambio en las dimensiones con los tratamientos térmicos aplicados. Sin embargo, la morfología de las paredes de los nanotubos se fue modificando con el tiempo y la temperatura de los tratamientos térmicos, evidenciándose la formación de cristales de anatasa. Incluso a partir de 550 ºC se observaron depósitos nanocristalinos de anatasa sobre la cara exterior de la pared de los nanotubos. En cuanto a la estructura cristalina, los recubrimientos resultaron amorfos previamente a los tratamientos térmicos y cristalinos en fase anatasa luego de los mismos, indicando la estabilización de esta fase incluso hasta los 650 ºC, temperatura a la que apareció la fase rutilo.

ACS Style

María Laura Vera; Edgard Rubén Henrikson; Hernán Darío Traid; Alicia Esther Ares; Marta Irene Litter. Influencia de los tratamientos térmicos en recubrimientos anódicos nanotubulares de TiO2. Matéria (Rio de Janeiro) 2018, 23, 1 .

AMA Style

María Laura Vera, Edgard Rubén Henrikson, Hernán Darío Traid, Alicia Esther Ares, Marta Irene Litter. Influencia de los tratamientos térmicos en recubrimientos anódicos nanotubulares de TiO2. Matéria (Rio de Janeiro). 2018; 23 (2):1.

Chicago/Turabian Style

María Laura Vera; Edgard Rubén Henrikson; Hernán Darío Traid; Alicia Esther Ares; Marta Irene Litter. 2018. "Influencia de los tratamientos térmicos en recubrimientos anódicos nanotubulares de TiO2." Matéria (Rio de Janeiro) 23, no. 2: 1.

Journal article
Published: 18 May 2018 in Ultrasonics Sonochemistry
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The sonochemical (850 kHz) reduction of Cr(VI) (0.3 mM, pH 2, reactor open to air) was analyzed in the presence of different additives. The effects on Cr(VI) reduction efficiency of added formic acid (FA, 10 mM), citric acid (Cit, 2 mM), ethylenediaminetetraacetic acid (EDTA, 1 mM), methanol (MeOH, 0.1 M), ethanol (EtOH, 0.1 M), 2-propanol (2-PrOH, 0.1 M), tert-butanol (t-BuOH, 0.1 M), phenol (PhOH, 2 mM) and sodium lauryl sulfate (SLS, 1 mM) have been evaluated in comparison with the system in the absence of additives. Complete Cr(VI) reduction was obtained only when using EDTA (at 120 min) and Cit (at 180 min). Cr(III) complexes with these compounds or with their degradation products were detected as final products. For EDTA, Cit, t-BuOH, FA and SLS, the Cr(VI) decay could be adjusted to a zero-order kinetics; in the cases of MeOH, EtOH and 2-PrOH, there was a deviation from the zero-order kinetics. The Cr(VI) conversion increased in the order SLS (very low) < no additive ≅ MeOH ≅ EtOH ≅ 2-PrOH < FA < t-BuOH < PhOH < Cit < EDTA. The role of EDTA and Cit in stabilizing intermediate Cr(V) peroxo compounds and enhancing their direct transformation into different Cr(III) species is considered a major factor in the acceleration of Cr(VI) reduction processes. Mechanistic pathways are proposed.

ACS Style

Jorge M. Meichtry; Mariel Slodowicz; Lucia Cancelada; Hugo Destaillats; Marta I. Litter. Sonochemical reduction of Cr(VI) in air in the presence of organic additives: What are the involved mechanistic pathways? Ultrasonics Sonochemistry 2018, 48, 110 -117.

AMA Style

Jorge M. Meichtry, Mariel Slodowicz, Lucia Cancelada, Hugo Destaillats, Marta I. Litter. Sonochemical reduction of Cr(VI) in air in the presence of organic additives: What are the involved mechanistic pathways? Ultrasonics Sonochemistry. 2018; 48 ():110-117.

Chicago/Turabian Style

Jorge M. Meichtry; Mariel Slodowicz; Lucia Cancelada; Hugo Destaillats; Marta I. Litter. 2018. "Sonochemical reduction of Cr(VI) in air in the presence of organic additives: What are the involved mechanistic pathways?" Ultrasonics Sonochemistry 48, no. : 110-117.

Book chapter
Published: 10 April 2018 in Visible Light-Active Photocatalysis
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The literature associated to the sensitization of TiO2 by modification with dyes is reviewed, including reactions leading to the transformation of dyes themselves, reactions of colorless pollutants, and hydrogen production, with emphasis on the involved mechanisms. The field of dye‐sensitized solar cells is briefly addressed.

ACS Style

Marta I. Litter; Enrique San Román; The Late María A. Grela; Jorge M. Meichtry; Hernán Bernardo Rodríguez. Sensitization of TiO2 by Dyes: A Way to Extend the Range of Photocatalytic Activity of TiO2 to the Visible Region. Visible Light-Active Photocatalysis 2018, 253 -282.

AMA Style

Marta I. Litter, Enrique San Román, The Late María A. Grela, Jorge M. Meichtry, Hernán Bernardo Rodríguez. Sensitization of TiO2 by Dyes: A Way to Extend the Range of Photocatalytic Activity of TiO2 to the Visible Region. Visible Light-Active Photocatalysis. 2018; ():253-282.

Chicago/Turabian Style

Marta I. Litter; Enrique San Román; The Late María A. Grela; Jorge M. Meichtry; Hernán Bernardo Rodríguez. 2018. "Sensitization of TiO2 by Dyes: A Way to Extend the Range of Photocatalytic Activity of TiO2 to the Visible Region." Visible Light-Active Photocatalysis , no. : 253-282.

Journal article
Published: 01 February 2018 in Journal of Environmental Management
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Reactive Black 5, RB5, has been used as a model azo dye to evaluate the removal efficiency of sorption on Macrocystis pyrifera biomass (Mpyr) and commercial zerovalent iron nanoparticles (nZVI) in individual and combined treatments. The best conditions for the treatment with the isolated materials were first determined, and then, in series and combined treatments were performed under these conditions, achieving removal efficiencies higher than 80% of the initial dye concentration. Strengths and weaknesses of all removal strategies (individual, in series and combined) are analyzed regarding the application on real effluents. Mpyr efficiently adsorbed RB5, but also increased the total organic content by partial dissolution of components of the algal biomass. Removal experiments with commercial nZVI were also efficient but liberated Fe to the solution, and sulfanilic acid was observed after the treatment as a product of RB5 degradation. In contrast, after the Mpyr treatment, no sulfanilic acid was detected, suggesting that sulfanilic acid is efficiently adsorbed by the biomass. The best condition was the integrated use of Mpyr and nZVI, with a remarkable removal efficiency (69–80%) obtained after only 1 h of treatment. Finally, nZVI were successfully immobilized in Mpyr, and the hybrid material was used to remove RB5 in continuous flow experiments at pH 3, obtaining a removal capacity of 39.9 mg RB5 g−1 after a total processed volume of 630 mL of [RB5]0 = 100 mg L−1.

ACS Style

Fabiana E. García; Josefina Del Ca Plaza Cazón; V. Nahuel Montesinos; Edgardo Donati; Marta I. Litter. Combined strategy for removal of Reactive Black 5 by biomass sorption on Macrocystis pyrifera and zerovalent iron nanoparticles. Journal of Environmental Management 2018, 207, 70 -79.

AMA Style

Fabiana E. García, Josefina Del Ca Plaza Cazón, V. Nahuel Montesinos, Edgardo Donati, Marta I. Litter. Combined strategy for removal of Reactive Black 5 by biomass sorption on Macrocystis pyrifera and zerovalent iron nanoparticles. Journal of Environmental Management. 2018; 207 ():70-79.

Chicago/Turabian Style

Fabiana E. García; Josefina Del Ca Plaza Cazón; V. Nahuel Montesinos; Edgardo Donati; Marta I. Litter. 2018. "Combined strategy for removal of Reactive Black 5 by biomass sorption on Macrocystis pyrifera and zerovalent iron nanoparticles." Journal of Environmental Management 207, no. : 70-79.

Journal article
Published: 01 January 2018 in Materials Research Bulletin
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ACS Style

María L. Vera; Hernán D. Traid; Edgard R. Henrikson; Alicia E. Ares; Marta I. Litter. Heterogeneous photocatalytic Cr(VI) reduction with short and long nanotubular TiO 2 coatings prepared by anodic oxidation. Materials Research Bulletin 2018, 97, 150 -157.

AMA Style

María L. Vera, Hernán D. Traid, Edgard R. Henrikson, Alicia E. Ares, Marta I. Litter. Heterogeneous photocatalytic Cr(VI) reduction with short and long nanotubular TiO 2 coatings prepared by anodic oxidation. Materials Research Bulletin. 2018; 97 ():150-157.

Chicago/Turabian Style

María L. Vera; Hernán D. Traid; Edgard R. Henrikson; Alicia E. Ares; Marta I. Litter. 2018. "Heterogeneous photocatalytic Cr(VI) reduction with short and long nanotubular TiO 2 coatings prepared by anodic oxidation." Materials Research Bulletin 97, no. : 150-157.

Journal article
Published: 20 April 2017 in Revista Cientifica TECNIA
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El agua es un fluido de proceso de mucha importancia en Tecnología Nuclear. La Unidad de Actividad Química (UAQ) ha dedicado mucho esfuerzo al estudio de sus propiedades fundamentales y de sus aplicaciones, con miras a optimizar el funcionamiento de los sistemas refrigerante, moderador y auxiliares en Centrales Nucleares. Uno de los aspectos fundamentales de estudio ha sido la necesidad de mantener agua muy pura en esos circuitos, para minimizar la corrosión de los materiales estructurales, y la incorporación de radionucleídos al agua. Esta incorporación es responsable de un incremento de las dosis ocupacionales de radiación de los trabajadores. La tecnología del agua como insumo de la industria nuclear requiere poseer capacidades en la producción y mantenimiento de agua extremadamente limpia. Dichas capacidades son las que se usan también para brindar soluciones a la provisión de agua a comunidades rurales aisladas, y a las pequeñas empresas para encontrar alternativas al tratamiento de sus efluentes. Los estudios para estos fines se han canalizado a través de una colaboración con las Universidades Nacionales de San Martín y de Tucumán. Palabras clave.-Agua, Industria nuclear. ABSTRACTWater is a fluid process of great importance in Nuclear Technology. Chemical Activity Unit (UAQ) has devoted much effort to the study of fundamental properties and applications in order to optimize the operation of cooling systems, and auxiliary moderator in nuclear power plants. One of the fundamental aspects of this study was the need for very pure water in these circuits, to minimize corrosion of structural materials, and the incorporation of radionuclides into the water. This incorporation is responsible for increased radiation dose occupational workers. Water technology as an input of the nuclear industry, for skills, is required in the production and maintenance of water extremely clean. These capabilities are also used to provide solutions to the water supply to isolated rural communities, and small businesses to find alternatives to treat their effluents. Studies for this purpose have been channeled through a partnership with the National Universities of San Martín and Tucumán. Keywords.- Water, Nuclear industry.

ACS Style

Christian Navntoft; Paula Araujo; Cecilia Mendive; Daniel S. Cicerone; R. Pizarro; Galo Soler-Illia; Laura Dawidowski; Marta I. Litter; Miguel A. Blesa; María C. Apella; Margarita Del V. Hidalgo; María G. García; Priscilla Powell; María Puchulu; D. Fernández. TECNOLOGÍAS ECONÓMICAS PARA LA DESINFECCIÓN Y DESCONTAMINACIÓN DE AGUA, AVANCES EN ARGENTINA. Revista Cientifica TECNIA 2017, 20, 45 .

AMA Style

Christian Navntoft, Paula Araujo, Cecilia Mendive, Daniel S. Cicerone, R. Pizarro, Galo Soler-Illia, Laura Dawidowski, Marta I. Litter, Miguel A. Blesa, María C. Apella, Margarita Del V. Hidalgo, María G. García, Priscilla Powell, María Puchulu, D. Fernández. TECNOLOGÍAS ECONÓMICAS PARA LA DESINFECCIÓN Y DESCONTAMINACIÓN DE AGUA, AVANCES EN ARGENTINA. Revista Cientifica TECNIA. 2017; 20 (1):45.

Chicago/Turabian Style

Christian Navntoft; Paula Araujo; Cecilia Mendive; Daniel S. Cicerone; R. Pizarro; Galo Soler-Illia; Laura Dawidowski; Marta I. Litter; Miguel A. Blesa; María C. Apella; Margarita Del V. Hidalgo; María G. García; Priscilla Powell; María Puchulu; D. Fernández. 2017. "TECNOLOGÍAS ECONÓMICAS PARA LA DESINFECCIÓN Y DESCONTAMINACIÓN DE AGUA, AVANCES EN ARGENTINA." Revista Cientifica TECNIA 20, no. 1: 45.

Journal article
Published: 01 April 2017 in Materials Chemistry and Physics
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ACS Style

Hernán D. Traid; María L. Vera; Alicia E. Ares; Marta I. Litter. Advances on the synthesis of porous TiO2 coatings by anodic spark oxidation. Photocatalytic reduction of Cr(VI). Materials Chemistry and Physics 2017, 191, 106 -113.

AMA Style

Hernán D. Traid, María L. Vera, Alicia E. Ares, Marta I. Litter. Advances on the synthesis of porous TiO2 coatings by anodic spark oxidation. Photocatalytic reduction of Cr(VI). Materials Chemistry and Physics. 2017; 191 ():106-113.

Chicago/Turabian Style

Hernán D. Traid; María L. Vera; Alicia E. Ares; Marta I. Litter. 2017. "Advances on the synthesis of porous TiO2 coatings by anodic spark oxidation. Photocatalytic reduction of Cr(VI)." Materials Chemistry and Physics 191, no. : 106-113.

Journal article
Published: 01 March 2017 in Catalysis Today
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Heterogeneous photocatalytic reduction of nitrate (2 mM) in the presence of formic acid (FA, 10 mM) using pure and modified TiO2 samples under UV–vis irradiation was performed at pH 3, and the evolution of the intermediate and final products was analyzed. For this work, commercial samples (Evonik P25 and Cristal Global PC500 and PC10) were modified by γ-radiolysis with two noble metal nanoparticles known to behave differently in NO3− transformation, Ag and Pd. P25 was modified with Ag (0.5 and 2% w/w), while PC10 and PC500 were modified with Pd (1% w/w). The order of the photocatalytic activity of the materials for NO3− transformation was 2 Ag-P25 > PC500 > 0.5 Ag-P25 ≈ P25 ≫ 1 Pd-PC500 > PC10 > 1 Pd-PC10. Nitrite formation was observed in all cases but at low amounts, and its concentration was negligible (≤1 μM) after complete NO3− reduction. Ammonium was found as final product and remained in considerable amounts at the end of the irradiation. The nitrogen balance accounted for a large amount of non-identified nitrogen products formed during the photocatalytic reaction, probably N2 or NO; this amount was higher for the P25 and PC500 pure samples. The efficiency on the use of FA as donor was evaluated and PC500 was found to be the most efficient sample in this sense. A mechanism is proposed to clarify the still not well understood process of TiO2 heterogeneous photocatalytic transformation of nitrate, based on literature data and detected products.

ACS Style

Alexandre Hérissan; Jorge M. Meichtry; Hynd Remita; Christophe Colbeau-Justin; Marta I. Litter. Reduction of nitrate by heterogeneous photocatalysis over pure and radiolytically modified TiO 2 samples in the presence of formic acid. Catalysis Today 2017, 281, 101 -108.

AMA Style

Alexandre Hérissan, Jorge M. Meichtry, Hynd Remita, Christophe Colbeau-Justin, Marta I. Litter. Reduction of nitrate by heterogeneous photocatalysis over pure and radiolytically modified TiO 2 samples in the presence of formic acid. Catalysis Today. 2017; 281 ():101-108.

Chicago/Turabian Style

Alexandre Hérissan; Jorge M. Meichtry; Hynd Remita; Christophe Colbeau-Justin; Marta I. Litter. 2017. "Reduction of nitrate by heterogeneous photocatalysis over pure and radiolytically modified TiO 2 samples in the presence of formic acid." Catalysis Today 281, no. : 101-108.

Journal article
Published: 01 January 2017 in Journal of Advanced Oxidation Technologies
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The basic and applied aspects of Fenton and Fenton-like processes for removal of pollutants using zerovalent iron materials, including nanoparticles, are reviewed in this article. Only those examples including the use of the iron materials together with hydrogen peroxide addition are included. The mechanistic aspects of homogeneous and heterogeneous Fenton processes, still under discussion, are displayed. The use of biogenic generated iron nanoparticles for removal of pollutants is discussed due to their novelty and economy of synthesis.

ACS Style

Marta I. Litter; Mariel Slodowicz. An overview on heterogeneous Fenton and photoFenton reactions using zerovalent iron materials. Journal of Advanced Oxidation Technologies 2017, 20, 1 .

AMA Style

Marta I. Litter, Mariel Slodowicz. An overview on heterogeneous Fenton and photoFenton reactions using zerovalent iron materials. Journal of Advanced Oxidation Technologies. 2017; 20 (1):1.

Chicago/Turabian Style

Marta I. Litter; Mariel Slodowicz. 2017. "An overview on heterogeneous Fenton and photoFenton reactions using zerovalent iron materials." Journal of Advanced Oxidation Technologies 20, no. 1: 1.