Papers by Gustavo Curutchet
International Journal of Environment and Health, 2018
The physicochemical properties of sediments and their ability to retain pollutants are affected b... more The physicochemical properties of sediments and their ability to retain pollutants are affected by both contamination and remediation processes. The aim of this study is to determine structural and physicochemical changes in real sediment contaminated with metals, subjected to bioleaching processes in a previous study. The sediment contaminated with heavy metals and samples of the same sediment treated with different heap leaching tests were used. They were characterised by potentiometric titrations, electrophoretic mobility, organic matter (OM), nuclear magnetic resonance (NMR), volatile solids and sulphides. For contaminated and treated sediment samples, the results of OM, sulphides, volatile solids to 600°, potentiometric titrations and zeta potential values depended on the bioleaching treatment performed previously. The contaminated sediment sample without any bioleaching treatment presented the greatest amount of OM and sulphides. Moreover, metal adsorption isotherms were performed. The contaminated sediment without bioleaching treatment was the one with the highest adsorption capacity. The baseline sample did not present a noticeable adsorption capacity. This study indicates the importance of the contribution of OM and sulphides to sediments and structural and physicochemical studies after remediation treatments.
Journal of Dispersion Science and Technology
Journal of Environmental Chemical Engineering, 2014
Waste water treatment is one of the environmental problems that concern the modern industrial soc... more Waste water treatment is one of the environmental problems that concern the modern industrial society. In particular, the disposition of colored effluents produced by textile, paper pulp, plastic and other industries represent a technological problem that affects several countries all around the world. It is difficult to calculate the annual amount of waste produced by these industries but some estimates indicate that there are over 100,000 types of synthetic dyes available in the market with an output of 7 Â 10 5 tons per year, and approximately 5-10% is discarded during their production and utilization [1-3]. There are several types of commercial dyes [1,4], and some of these dyes posses a high resistance to biodegradation and persist a long time in the environment [5-7]. These compounds and their degradation byproducts are generally believed to be carcinogenic or toxic and become harmful to humans or to the environment where they 26 are discarded [8-13] and are easily detectable with the naked eye 27 at very low concentrations. Triarylmethane dyes (TAM) are 28 recalcitrant dyes that have been used as antimicrobial and 29 antifungal agents [14-16]. These compounds typically display a 30 net positive charge, being crystal violet (one of the best known 31 members of this family of compounds) a good model to represent 32 cationic dyes. 33 Adsorption processes have been proposed as a fast alternative 34 to remove contaminants from water. Several natural low cost 35 adsorbents have been tested to remove synthetic dyes [3,17]. In 36 particular, montmorillonite (a clay belonging to the family of 37 smectites) have been broadly studied as adsorbents of synthetic 38 dyes [18-20]. Smectite clays have a layered structure where each 39 layer is composed by tetrahedral silicate units fused into an edge-40 shared octahedral plane of aluminum. The isomorphic substitution 41 of Al(III) for Fe(II) or Mg(II) and Si(IV) for Al(III) generates charge 42 deficiencies on the surface and interlayer space. When Al(III) is 43 replaced by Mg(II) the structure corresponds to montmorillonite 44 (MMT). The intrinsic negative charge is compensated with 45 inorganic cations (as Na(I) or Ca(II) in MMT) in the interlayer 46 that can be exchanged by other inorganic or organic cations, being 47 suitable for adsorption of cationic synthetic dyes. However, after 48 adsorption and separation from the aqueous effluent a new solid
Se debate las tensiones entre contaminacion y autodepuracion de la urbe metropolitana, estudiando... more Se debate las tensiones entre contaminacion y autodepuracion de la urbe metropolitana, estudiando arroyos que la atraviesan, entubados en gran parte de su recorrido, saliendo a cielo abierto en espacios urbanos con altos niveles de pobreza y contaminacion. Constituyen zonas urbano-perifericas, hasta fines del siglo XX, humedales y campos transformados en espacios densamente poblados y escasamente urbanizados. El barrio Carcova se ubica en Jose Leon Suarez, General San Martin. Esta atravesado por un tramo del canal Jose Leon Suarez que arrastra –desde aguas arriba– carga de contaminantes de descargas cloacales e industriales, recibiendo aportes de los desagues domesticos del barrio. Contrariando las hipotesis de que estos barrios son los principales productores de contaminacion de la urbe, se propone lo contrario: en el trayecto en que el canal discurre por el barrio, el agua se limpia y los sedimentos acumulan los contaminantes. Estos barrios ofician como plantas depuradoras de la m...
Ambiente & sociedade, 2012
Este artículo presenta resultados de una investigación transdisciplinaria que combina el conocimi... more Este artículo presenta resultados de una investigación transdisciplinaria que combina el conocimiento local con saberes de las ciencias sociales y naturales con el propósito último de comprender y remediar los problemas socioambientales de barrios hiperdegradados. La investigación fue realizada en un barrio de la Región Metropolitana de Buenos Aires, Argentina. Como punto de partida, desde 2008 se llevó a cabo un trabajo etnográfico sobre la percepción de los vecinos acerca de los problemas asociados a la contaminación. En ese proceso, se diseñó y montó un observatorio ambiental permanente centrado en el monitoreo de la red de agua potable y los desagües pluviales/cloacales y los procesos de autodepuración en los arroyos que bordean el barrio. Una de las principales innovaciones de la investigación es que la población participa en el diseño del observatorio y, a través de las escuelas del barrio, en la toma y análisis de muestras.
Process Biochemistry, 1997
THEOREM. Let ƒ, g be mappings from {X\X »-n] to some field F of characteristic 0. Then ƒ(!)= X(si... more THEOREM. Let ƒ, g be mappings from {X\X »-n] to some field F of characteristic 0. Then ƒ(!)= X(signt)g(t*A)^g(A)= X K,J(n), zeSn nt-n AMS (MOS) subject classifications (1970). Primary 05A17 ; Secondary 05B20.
Process Biochemistry, 1996
ELSEVIER 0032-9592{95)00037-2 Process Biochemistry Vol. 31, No. 2, pp. t 29-134, 1996 Copyright 1... more ELSEVIER 0032-9592{95)00037-2 Process Biochemistry Vol. 31, No. 2, pp. t 29-134, 1996 Copyright 1995 Elsevier Science Ltd Printed in Great Britain. All rights reserved 0032-9592/96 S 15.00 + 0.00 Bioleaching of Covellite Using Pure and Mixed Cultures of Thiobacillus ...
International Biodeterioration & Biodegradation, 2003
In this paper, we present the indirect Cr(VI) reduction by Acidithiobacillus thiooxidans using su... more In this paper, we present the indirect Cr(VI) reduction by Acidithiobacillus thiooxidans using sulfur as energy source under aerobic conditions and the subsequent Cr(III) precipitation by Desulfovibrio sp. under anaerobic conditions. Cr(VI) reduction is promoted by intermediate-products such as sulÿte and thiosulfate. Both processes have been operated sequentially under continuous ow conditions to decontaminate a 5 mg l −1 Cr(VI) solution.
Latin American applied …, 2002
vol. 32 número4 Microstructure and hydrogen absorption behavior of Zr0. 9Ti0. 1Mn0. 66V0. 46Ni1. ... more vol. 32 número4 Microstructure and hydrogen absorption behavior of Zr0. 9Ti0. 1Mn0. 66V0. 46Ni1. 1 under electrochemical and gaseous media conditions Evaluation of the protective performance of several duplex systems exposed to industrial atmosphere índice de ...
Brazilian Journal of Chemical Engineering, 2003
... Print version ISSN 0104-6632. Braz. J. Chem. Eng. vol.20 no.1 São Paulo Jan./Mar. 2003. doi: ... more ... Print version ISSN 0104-6632. Braz. J. Chem. Eng. vol.20 no.1 São Paulo Jan./Mar. 2003. doi: 10.1590/S0104-66322003000100013. Reduction of chromium (VI) by the indirect action of Thiobacillus thioparus. E.Donati; C.Oliver; G.Curutchet. ...
Biotechnology Letters, 1992
There is a significant inhibition of the growth of Thiobacillus ferrooxidans in the presence of i... more There is a significant inhibition of the growth of Thiobacillus ferrooxidans in the presence of iron (III), but this does not affect bacterial leaching. Moreover, the insoluble hydrolytic products (jarosites) have no influence, except from a mechanical point of view when they are generated "in situ'.
Industrial & Engineering Chemistry Research, 2010
The applicability of different photochemical advanced oxidation technologies (PAOTs), namely, dir... more The applicability of different photochemical advanced oxidation technologies (PAOTs), namely, direct UV-C photolysis, UV-C/H 2 O 2 and UV-A/TiO 2 heterogeneous photocatalysis (HP), and photo-Fenton reactions (UV-A/ H 2 O 2 /Fe 2+ , PF), for the degradation of 300 mg L-1 nonylphenol ethoxylate-9 (NPE-9) in water is described. Different kinetic regimes for each PAOT were found, and as a result, comparative efficiencies could be obtained only from final parameters such as NPE-9 conversion, TOC decrease, and aldehyde production after 3 h of treatment. The initial photonic efficiencies indicate, however, that UV-A processes make better use of photons than UV-C processes. Preliminary optimization of PF systems showed that the most efficient NPE-9/H 2 O 2 / Fe 2+ molar ratio was 1:1:0.5. Degradation products were partially investigated. Fortunately, toxic 4-nonylphenol was never found as a byproduct of the degradation after any of the treatments. Aldehydes were formed in all of the processes, but they appeared at a low extent in PF reactions. Therefore, PF treatments were considered to be the best degradation processes.
Environmental Technology, 2008
El proposito de este trabajo es realizar el tratamiento de un efluente que contiene el fungicida ... more El proposito de este trabajo es realizar el tratamiento de un efluente que contiene el fungicida imazalil, mediante la combinacion de un tratamiento avanzado de oxidacion foto-Fenton y sistemas biologicos.
Water, Air, & Soil Pollution
To improve hexavalent chromium (Cr(VI)) retention of montmorillonite (Mt) at pH 3, Mt sample was ... more To improve hexavalent chromium (Cr(VI)) retention of montmorillonite (Mt) at pH 3, Mt sample was subjected to different treatments: thermal ones at 600 °C or 950 °C, 2 h, or mechanical grinding for 300 s. Then, the obtained products were loaded with different octadecyl trimethyl ammonium loading and 50% and 100% of Mt cation exchange capacity (CEC). The samples were characterized by several techniques at each stage. Differential thermogravimetric analysis (DTGA) performed on the products allowed determining the actual surfactant amount related to the internal or external surface by cation exchange and Van der Waals (VdW) mechanisms, respectively, taking into account the CEC of the thermal or mechanical pretreated Mt base sample used. X-ray diffraction (XRD) analyses revealed that the surfactant loading allowed the reversal of the collapsed interlayer after both treatments. The samples subjected to the thermal treatment at 600 °C and the raw Mt samples exhibit higher positive zeta potential values than the mechanical pretreated Mt ones with 100% of the CEC surfactant loaded at pH 3. This was directly related to the external surface covered by the surfactant. The agreement between the results of the surfactant coverage on the external surface and Cr(VI) removal at pH 3 indicates that the electrostatic mechanism is the main driving force for the sorption of Cr(VI). These synthesized sorbents achieve similar Cr(VI) retention using less than half the surfactant amount of already published studies.
Materials Chemistry and Physics
Abstract In this work, organo-montmorillonite (organo-Mt) and organo-synthetic mica (organo-mica)... more Abstract In this work, organo-montmorillonite (organo-Mt) and organo-synthetic mica (organo-mica), obtained by quaternary or primary amine cations (octadecyltrimethylammonium (ODTMA) or octadecyl-amine (ODA), respectively) exchanged at 50% and 100% of their respective CEC, were thoroughly characterized and tested for pyrimethanil uptake. The interlayer entrance of both surfactants for Mt loaded at 50% and 100% CEC indicated a close basal space (of around 1.5 and 1.8 nm, respectively). However, for synthetic mica (Na-Mica-4) the basal space shifted to higher values (3.5 and 3.9 nm and 4.7 and 5.0 nm, for ODTMA and ODA at 50% and 100% CEC, respectively) than those of organo-Mts, keeping the interlayer surface partially free for ODTMA-Mica-4 samples. Tg analysis revealed that the actual ODA loadings were around 40% and 80% for both clays and for ODTMA exchanged Mts, while the actual ODTMA loading for organo-mica samples did not exceed 10.6%. The decrease of negative zeta potential evidenced the presence of ODA or ODTMA at the external surfaces of organo-Mt, while the zeta potential curves for organo-mica samples described the system as a mixture of individual surfactants and Na-Mica-4 sample. Total specific surface area (TSSA) and contact angle (CA) measurements revealed a general hydrophobicity increment with the presence of both surfactants. Interrelations of these parameters point out the different affinity and steric hindrance of the polar head of both surfactants with the solid surfaces, which also conditioned pyrimethanil adsorption.
Frontiers in Microbiology
Millimeter-length cables of bacteria were discovered growing along a graphite-rod electrode servi... more Millimeter-length cables of bacteria were discovered growing along a graphite-rod electrode serving as an anode of a microbial electrolysis cell (MEC). The MEC had been inoculated with a culture of Fe-reducing microorganisms enriched from a polluted river sediment (Reconquista river, Argentina) and was operated at laboratory controlled conditions for 18 days at an anode poised potential of 240 mV (vs. Ag/AgCl), followed by 23 days at 480 mV (vs. Ag/AgCl). Anode samples were collected for scanning electron microscopy, phylogenetic and electrochemical analyses. The cables were composed of a succession of bacteria covered by a membranous sheath and were distinct from the known “cable-bacteria” (family Desulfobulbaceae). Apparently, the formation of the cables began with the interaction of the cells via nanotubes mostly located at the cell poles. The cables seemed to be further widened by the fusion between them. 16S rRNA gene sequence analysis confirmed the presence of a microbial comm...
Journal of Environmental Management
Minerals, 2021
The physicochemical and textural characteristics of river sediments and, essentially, their clays... more The physicochemical and textural characteristics of river sediments and, essentially, their clays, are at the center of a network of biological and geochemical factors that are mutually modifying. Therefore, the contamination, the characteristics of the clays, and the associated microorganisms strongly influence each other. In this work, sediments from two sites of the urban Reconquista River, near Buenos Aires City, Argentina, exposed to different environmental contexts were characterized. The huge differences in the organic matter content in the vertical profile between both sediments strongly evidenced the polluted status of San Francisco (SF) site as opposed to the Dique Roggero (DR) site. Thorough physicochemical and textural characterization of the sediments and their clay fraction performed by pH, Oxidation-reduction potential (ORP), spectrophotometry, XRD, laser diffraction, N2 adsorption–desorption isotherms, EDS, and SEM measurements revealed that organic matter (DR: 41 ± ...
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Papers by Gustavo Curutchet