40 research outputs found
Bioaccessible heavy metals-sediment particles from Reconquista River induce lung inflammation in mice
The Reconquista River (RR), one of the most polluted watercourses in Argentina, receives effluent discharges from heavily industrialized and highly populated settlements. During winter and summer, the floodplain remains dry, producing the oxidation of sulfide and organic matter present in the sediment, making heavy metals more bioaccessible. Dispersion of this sediment occurs, and thus harmful effects on the pulmonary health of residents and workers inhabiting the RR bank may take place. The authors characterized the sediment particles of the RR (RR-PM) morphologically by scanning electron microscopy and its elemental composition by energy dispersive X-ray spectroscopy (EDX) and Community Bureau of Reference (BCR) sequential extraction. Furthermore, the authors evaluated its biological impact on the respiratory system of BALB/c mice, generating four groups: control healthy, sensibilized with ovalbumin, exposed to particles, and sensibilized and exposed to particles. Sediment particles of the Reconquista River contained fine particulate matter, with a high concentration of bioaccessible Cu and Zn. The authors found that animal exposure to RR-PM caused polymorphonuclear cell lung infiltration, augmentation of O2-, increase of proinflammatory cytokines (tumor necrosis factor alpha [TNFα], interleukin-6 [IL-6]) and apoptosis. This adverse response was more dramatic in the sensibilized and exposed to particles group. Even more, they proved the bioaccessible fraction present in the RR-PM to be responsible for these harmful effects. The authors conclude that RR-PM produces an adverse biological impact on the airways of healthy animals, which is largely aggravated in previously sensibilized animals.Fil: Ferraro, Sebastián Ariel. Universidad Nacional de San MartÃn. Instituto de Investigación e IngenierÃa Ambiental. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e IngenierÃa Ambiental; ArgentinaFil: Curutchet, Gustavo Andres. Universidad Nacional de San MartÃn. Instituto de Investigación e IngenierÃa Ambiental. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e IngenierÃa Ambiental; ArgentinaFil: Tasat, Deborah Ruth. Universidad de Buenos Aires. Facultad de OdontologÃa. Cátedra de HistologÃa y EmbriologÃa; Argentin
Uranium uptake by Montmorillonite-biomass complexes
Montmorillonite clays and biomass have noticeable metal sorption capacity. Clays or biomass are difficult to separate from the solution when used as sorbent materials. A methodology to retain biomass and improve separation processes is to generate clay biopolymers matrices from fungal biomass grown on a natural Montmorillonite (MMT). The objective of this study is to generate and characterize clay biopolymers matrices and evaluate their uranium adsorption capacity. The generated clay biopolymers (BMMTs) were characterized through X-ray diffraction, measurement of the apparent diameter of particles, and electrophoretic mobility. Some BMMTs showed greater Uranium-specific adsorption capacity than that found for MMT. The X-ray diffraction analysis indicated that the Uranium was located partially in the clay interlayer. The BMMT surfaces were more negatively charged than the MMT surface, thus favoring their uranium uptake. Also, immobilization of the biomass and better coagulation of the system were achieved. These preliminary studies indicate that BMMTs have a great potentiality for uranium uptake processes.Centro de TecnologÃa de Recursos Minerales y Cerámic
Antarctic yeasts: Potential use in a biologic treatment of textile azo dyes
We investigated the dye-removal potential of a collection of 61 cold-adapted yeasts from the King George Island, Antarctica, on agar plates supplemented with 100 mg L–1 of several textile dyes; among which isolates 81% decolorized Reactive Black 5 (RB-5), with 56% decolorizing Reactive Orange 16, but only 26% doing so with Reactive Blue 19 and Acid Blue 74. Furthermore, we evaluated the ligninolytic potential using 2,2ʹ-azino-bis(3-ethylbenzothiazoline-6-sulfonic-acid) diammonium salt-, 3,5-dimethoxy-4-hydroxybenzaldehydazine-, or manganese-supplemented plates but detected no activity, possibly due to a dye-removal mechanism involving reductases. The removal kinetics were studied in liquid medium supplemented with 100 mg L–1 of RB-5 in a selection of 9 yeasts. The highest volumetric-removal rates (η) were found for Candida sake 41E (4.14 mg L–1 h–1), Leucosporidium muscorum F20A (3.90 mg L–1 h–1), and Cystofilobasidium infirmominiatum F13E (3.90 mg L–1 h–1). Different UV–Vis spectra were obtained if the dye removal occurred by biodegradation or biosorption/bioaccumulation. L. muscorum F20A was selected to study the dye-removal mechanism of RB-5 and the effect of different chemical and environmental parameters on the process. Optimum dye-removal conditions were obtained with 10 g L–1 of glucose within an initial medium pH range of 5.0 to 6.0. Up to 700 mg L–1 of dye could be removed in 45 h. High-performance liquid chromatography profiles obtained were consistent with a biodegradation of the dye. Phytotoxicity was estimated by calculating the 50%-inhibition concentration (IC50) with Lactuca sativa L. seeds. These findings propose psychrophilic yeasts as a novel environmentally suitable alternative for the treatment of dye-industry wastewaters.Fil: Ruscasso, Maria Florencia. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Cavello, Ivana Alejandra. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Curutchet, Gustavo Andres. Universidad Nacional de San MartÃn. Instituto de Investigación e IngenierÃa Ambiental. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e IngenierÃa Ambiental; ArgentinaFil: Cavalitto, Sebastian Fernando. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentin
Selection of natural bacterial communities for the biological production of hydrogen
Current processes used for the production of hydrogen consume a great part of the energy they produce and/or depend on fossil fuel consumption, making them inefficient and harmful to the environment. Obtaining hydrogen from living systems by fermentation of organic matter considered waste is a promising alternative for the future. Especially when you take into account that the biological production of hydrogen is intrinsically linked to the degradation of said organic matter. In this paper, we explore the efficiency of different bacterial communities (also called consortia) for anaerobic fermentation of carbohydrates. The evaluated consortia were obtained from soil, commercial compost and sludge from a sewage treatment plant. The cultures that produced the highest amounts of hydrogen were those in which the inoculums used came from sludge and compost. Both reached a maximum accumulated concentration of approximately 30% of biological hydrogen in the gas mixture on day 8 of the fermentation process, as estimated by gas chromatography.Fil: GarcÃa, Rodrigo Enrique. Ministerio de Defensa. Armada Argentina. Dirección Gral. de Investigación y Desarrollo de la Ara; ArgentinaFil: MartÃnez, Verónica Laura. Ministerio de Defensa. Instituto de Investigaciones CientÃficas y Técnicas para la Defensa; ArgentinaFil: Franco, Juan Isidro. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Ministerio de Defensa. Instituto de Investigaciones CientÃficas y Técnicas para la Defensa; ArgentinaFil: Curutchet, Gustavo Andres. Universidad Nacional de San MartÃn; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentin
Sorbent materials characterization based on mechanical or thermal pretreated montmorillonite modified by surfactant loading for improved chromium retention
t 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.Fil: Fernández Morantes, César. Universidad Nacional de San MartÃn; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones CientÃficas. Centro de TecnologÃa de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de TecnologÃa de Recursos Minerales y Cerámica; ArgentinaFil: Yarza, Florencia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones CientÃficas; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones CientÃficas. Centro de TecnologÃa de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de TecnologÃa de Recursos Minerales y Cerámica; ArgentinaFil: Montes, MarÃa Luciana. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Instituto de FÃsica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FÃsica La Plata; ArgentinaFil: Mercader, Roberto Carlos. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Instituto de FÃsica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FÃsica La Plata; ArgentinaFil: Curutchet, Gustavo Andres. Universidad Nacional de San MartÃn. Instituto de Investigación e IngenierÃa Ambiental. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e IngenierÃa Ambiental; ArgentinaFil: Torres Sanchez, Rosa Maria. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones CientÃficas. Centro de TecnologÃa de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de TecnologÃa de Recursos Minerales y Cerámica; Argentin
Debaryomyces hansenii F39A como bioadsorbente para la remoción de colorantes textiles
Many industries generate a considerable amount of wastewater containing toxic and recalcitrant dyes. The main objective of this research was to examine the biosorption capacity of Reactive Blue 19 and Reactive Red 141 by the Antarctic yeast Debaryomyces hansenii F39A biomass. Some variables, including pH, dye concentration, amount of adsorbent and contact time, were studied. The equilibrium sorption capacity of the biomass increased with increasing initial dye concentration up to 350 mg/l. Experimental isotherms fit the Langmuir model and the maximum uptake capacity (qmax) for the selected dyes was in the range of 0.0676?0.169 mmol/g biomass. At an initial dye concentration of 100 mg/l, 2 g/l biomass loading and 20 ± 1 °C, D. hansenii F39A adsorbed around 90% of Reactive Red 141 and 50% of Reactive Blue 19 at pH 6.0. When biomass loading was increased (6 g/l), the uptake reached up to 90% for Reactive Blue 19. The dye uptake process followed a pseudo-second-order kinetics for each dye system. As seen throughout this research study, D. hansenii has the potential to efficiently and effectively remove dyes in a biosorption process and may be an alternative to other costly materials.ResumenMuchas industrias generan un gran volumen de aguas residuales que contienen colorantes, los cuales son compuestos tóxicos y recalcitrantes. El objetivo principal de este estudio fue examinar la capacidad bioadsortiva de la biomasa de la levadura antártica Debaryomyces hansenii F39A, en presencia de los colorantes azul reactivo 19 y rojo reactivo 141. Se estudiaron algunas variables del proceso, incluyendo el pH, la concentración de colorante y de adsorbente utilizada y el tiempo de contacto. La capacidad de adsorción se incrementó al aumentar la concentración del adsorbato hasta 350 mg/L. Los datos de las isotermas obtenidas experimentalmente se ajustaron con el modelo de Langmuir, donde la capacidad máxima de adsorción (Qmáx) para ambos colorantes se encuentra dentro del rango 0,0676-0,169 mmol/g de biomasa. A una concentración inicial de 100 mg/L de adsorbato en presencia de 2 g/L de adsorbente a 20 ? 1 ?C y un valor de pH = 6, D. hansenii F39A fue capaz de adsorber aproximadamente un 90% del rojo reactivo 141 y un 50% del azul reactivo 19. Cuando la concentración de biomasa se incrementó (6 g/L), la remoción del azul reactivo 19 alcanzó el 90%. El proceso de adsorción para cada colorante sigue una cinética de pseudo segundo orden. D. hansenii tiene el potencial de remover eficientemente los colorantes estudiados, a través de un proceso de bioadsorción y puede considerarse una alternativa a otros materiales adsorbentes de mayor costo.Muchas industrias generan un gran volumen de aguas residuales que contienen colorantes, los cuales son compuestos tóxicos y recalcitrantes. El objetivo principal de este estudio fue examinar la capacidad bioadsortiva de la biomasa de la levadura antártica Debaryomyces hansenii F39A, en presencia de los colorantes azul reactivo 19 y rojo reactivo 141. Se estudiaron algunas variables del proceso, incluyendo el pH, la concentración de colorante y de adsorbente utilizada y el tiempo de contacto. La capacidad de adsorción se incrementó al aumentar la concentración del adsorbato hasta 350 mg/L. Los datos de las isotermas obtenidas experimentalmente se ajustaron con el modelo de Langmuir, donde la capacidad máxima de adsorción (Qmáx) para ambos colorantes se encuentra dentro del rango 0,0676-0,169 mmol/g de biomasa. A una concentración inicial de 100 mg/L de adsorbato en presencia de 2 g/L de adsorbente a ± 1 °C y un valor de pH = 6, D. hansenii F39A fue capaz de adsorber aproximadamente un 90% del rojo reactivo 141 y un 50% del azul reactivo 19. Cuando la concentración de biomasa se incrementó (6 g/L), la remoción del azul reactivo 19 alcanzó el 90%. El proceso de adsorción para cada colorante sigue una cinética de pseudo segundo orden. D. hansenii tiene el potencial de remover eficientemente los colorantes estudiados, a través de un proceso de bioadsorción y puede considerarse una alternativa a otros materiales adsorbentes de mayor costo.Fil: Ruscasso, Maria Florencia. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Bezus, Brenda. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Garmendia, Gabriela. Universidad de la República; UruguayFil: Vero, Silvana. Universidad de la República; UruguayFil: Curutchet, Gustavo Andres. Universidad Nacional de San MartÃn. Instituto de Investigación e IngenierÃa Ambiental. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e IngenierÃa Ambiental; ArgentinaFil: Cavello, Ivana Alejandra. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Cavalitto, Sebastian Fernando. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentin
Contamination alters the physicochemical and textural characteristics of clays in the sediments of the peri urban reconquista river, affecting the associated indigenous microorganisms
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 ± 5 g kg−1; SF: 150 ± 30 g kg−1 ) intervened in the retention of heavy metals (DR: 5.6 mg kg−1 Zn, 7 mg kg−1 Cu, 3.1 kg−1 Cr; SF: 240 mg kg−1 Zn, 60 mg kg−1 Cu, 270 mg kg−1 Cr) and affected the level of association and the formation of mineral–organic aggregates (DR: 15 ± 3 µm; SF: 23 ± 4 µm). This can be decisive in the surface interaction required for the establishment of bacterial assemblages, which determine the biogeochemical processes occurring in sediments and have a key role in the fate of contaminants in situ and in the remediation processes that need to be applied to restore the anoxic contaminated sediments.Fil: Tufo, Ana Elisabeth. Universidad Nacional de San MartÃn. Instituto de Investigación e IngenierÃa Ambiental. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e IngenierÃa Ambiental; ArgentinaFil: Vázquez, Susana Claudia. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de NanobiotecnologÃa. Universidad de Buenos Aires. Facultad de Farmacia y BioquÃmica. Instituto de NanobiotecnologÃa; ArgentinaFil: Porzionato, Natalia Florencia. Universidad Nacional de San MartÃn. Instituto de Investigación e IngenierÃa Ambiental. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e IngenierÃa Ambiental; ArgentinaFil: Grimolizzi, MarÃa Celeste. Universidad Nacional de San MartÃn. Instituto de Investigación e IngenierÃa Ambiental. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e IngenierÃa Ambiental; ArgentinaFil: Prados, Maria Belen. Comisión Nacional de EnergÃa Atómica. Gerencia del Area de Seguridad Nuclear y Ambiente. Instituto de EnergÃa y Desarrollo Sustentable; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Sica, Mauricio Pablo. Comisión Nacional de EnergÃa Atómica. Gerencia del Area de Seguridad Nuclear y Ambiente. Instituto de EnergÃa y Desarrollo Sustentable; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Curutchet, Gustavo Andres. Universidad Nacional de San MartÃn. Instituto de Investigación e IngenierÃa Ambiental. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e IngenierÃa Ambiental; Argentin
Factors affecting chromium(VI) reduction by Thiobacillus ferrooxidans
The ability of Thiobacillus ferrooxidans cultures to reduce chromium(VI) to chromium(III) was evaluated under different conditions. In T. ferrooxidans cultures with sulphur as energy source, the capacity for chromium(VI) reduction was related to the generation of sulphur compounds (sulphite, thiosulphate and polythionates) with high reducing power. In contrast with other chromium(VI)-reducing microorganisms, T. ferrooxidans showed higher chromium(VI) reduction at low pH. The reduction of chromium(VI) also increased with the age of the culture. A T. ferrooxidans cells were capable of growing under anaerobic conditions with chromium(VI) as the terminal-electron acceptor.Fil: QuiIntana, M.. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Curutchet, Gustavo Andres. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Donati, Edgardo Ruben. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentin
Biocatalysed acidification and metal leaching processes in sediments of polluted urban streams
Sediments of fluvial streams are a sink for pollutants such as heavy metals and organic recalcitrant compounds. In anoxic conditions, sulphide generation and alkalinisation cause precipitation of heavy metals. The redox potential of the system could change to higher values, mainly owing to oxygen exposition generated by anthropogenic disturbances of the sediment such as dredging operations. Knowledge about the mechanisms involved is fundamental to assess the risk of acid generation and rise in heavy metals bioavailability. In this paper, the characterisation and assessment of acidification risk of sediments of a contaminated stream near Buenos Aires was carried out by static and kinetic assays. Speciation of heavy metals was determined after metal sequential extraction procedure. Also, re-suspension of sediments assay in batch mode, with and without Acidithiobacillus ferrooxidans inoculum, was carried out to assess the chemical changes that occur at oxygen exposure, verifying the acidification and heavy metal release processes.Fil: Porzionato, Natalia Florencia. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Nacional de San MartÃn. Instituto de Investigación en IngenierÃa Ambiental; ArgentinaFil: Candal, Roberto Jorge. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Nacional de San MartÃn. Instituto de Investigación en IngenierÃa Ambiental; ArgentinaFil: Curutchet, Gustavo Andres. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Nacional de San MartÃn. Instituto de Investigación en IngenierÃa Ambiental; Argentin
Studies on bioremediation of Zn and acid waters using Botryococcus braunii
In the present article the effects of Zn(II) on Botryococcus braunii in terms of growth and the photosynthesis-respiration metabolism and the ability of this microalgae to remove zinc present in wastewaters is described. The photosynthetic and respiration rates are affected by increasing metal concentration in solution, and therefore B. braunii growth rate decreases to a half, nevertheless the maximum value of biomass reached (770 ± 40 mg l-1) is the same and the biomass remains viable throughout the range of concentrations studied (0-80 mg l-1). B. braunii exposed the ability to reverse the acidic conditions of the medium, showing a pH increase from 5.2 till values above 8.0 favoring the precipitation of different zinc compounds. Zn(II) specific removal increases along with initial metal concentration. The net adsorption capacity was determined, and the Freundlich, Langmuir and Hill models were applied. The stoichiometric relationship between H+ release and zinc uptake in slightly acidic conditions is 1:1, and the adsorption kinetics follows a pseudo-second order model. The amount of metal removed increase when metabolic processes are involved. Removal of Zn with successive additions was achieved along 200 days, reaching a value of zinc removal of 3.4 g g-1. The remediation of heavy metals (zinc, nickel and copper) and nitrates present in a leachate obtained from a bioleaching process was successfully performed. The present work represents a new approach on the biotechnological potential of B. braunii to grow in acidic conditions and to remove zinc, while differentiates passive adsorption from metabolically active remediation.Fil: Areco, MarÃa del Mar. Universidad Nacional de San MartÃn. Instituto de Investigación e IngenierÃa Ambiental. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e IngenierÃa Ambiental; Argentina. Universidad Nacional de San MartÃn. Escuela de Ciencia y TecnologÃa; ArgentinaFil: Haug, Erika. Universidad Nacional de San MartÃn. Instituto de Investigación e IngenierÃa Ambiental. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e IngenierÃa Ambiental; Argentina. Universidad Nacional de San MartÃn. Escuela de Ciencia y TecnologÃa; ArgentinaFil: Curutchet, Gustavo Andres. Universidad Nacional de San MartÃn. Instituto de Investigación e IngenierÃa Ambiental. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e IngenierÃa Ambiental; Argentina. Universidad Nacional de San MartÃn. Escuela de Ciencia y TecnologÃa; Argentin