Browsing by Autor "Carla Oporto"

Now showing 1 - 10 of 10

Accelerating innovative water treatment in Latin America
(Nature Portfolio, 2023) Alexsandro J. dos Santos; Haruna Luz Barazorda-Ccahuana; Griselda Caballero-Manrique; Yvens Chérémond; Patricio J. Espinoza‐Montero; J. Ricardo González-Rodríguez; Ulises Jäuregui‐Haza; Marcos R.V. Lanza; Andrea Nájera; Carla Oporto
Author Correction: Accelerating innovative water treatment in Latin America
(Nature Portfolio, 2023) Alexsandro J. dos Santos; Haruna Luz Barazorda-Ccahuana; Griselda Caballero-Manrique; Yvens Chérémond; Patricio J. Espinoza‐Montero; J. Ricardo González-Rodríguez; Ulises Jäuregui‐Haza; Marcos R.V. Lanza; Andrea Nájera; Carla Oporto
DGT-measured fluxes explain the chloride-enhanced cadmium uptake by plants at low but not at high Cd supply
(Springer Science+Business Media, 2008) Carla Oporto; Erik Smolders; Fien Degryse; Liesbeth Verheyen; Carlo Vandecasteele
Efficiencies of available organic mixtures for the biological treatment of highly acidic-sulphate rich drainage of the San Jose mine, Bolivia
(Taylor & Francis, 2019) Carla Oporto; Gabriela Baya; Carlo Vandecasteele
The environmental contamination due to mining activities in the Andean region of Bolivia is a serious concern, as it leads to highly acidic (pH 2.4) acid mine drainage (AMD), severely polluted by sulfate (>12,000 mg L-1). Passive bioreactors entailing biological sulfate reduction and removal of metals through sulfide precipitation have been recognized as a promising biotechnology. The reactivity of mixtures containing locally available substrates: sheep manure, compost and straw, was assessed through batch experiments conducted with a synthetic solution simulating the composition of AMD from San José mine (Oruro). The removal of sulfate and metals was successful in all reactors, at the end of the experiment (56 days) sulfate concentrations dropped to 1378-2081 mg L-1, corresponding to a removal efficiency between 84% and 89%, while average removal for Fe, Zn, Pb, and Cd were 99.8%, 98.5%, 94.7%, 98.6%, respectively. The sulfate and metal removal showed three phases. In the first phase, the removal was independent of the organic composition and attributable to pH-controlled mechanisms i.e. adsorption, precipitation of oxy(hydroxides) and co-precipitation. During the second phase, sulfate and metals concentrations remained rather constant; while in the third phase, the removal was affected by the organic matter composition. Sulfate removal rate attained the highest values (227-243 mg L-1 d-1) in the third phase, and it was attributable to biological reduction with not sulfate limitation. The depletion of nutrients rather than the sulfate availability may have limited the sulfate removal at the end of the experiment.
Electrochemical technologies as modular adaptative decentralized treatment systems to enact water security for Latin America: Insights and prospects
(Elsevier BV, 2023) Alexsandro J. dos Santos; Rodrigo Vargas; Carla Oporto; Marcos R.V. Lanza; Abdoulaye Thiam; Ricardo A. Torres-Palma; Ricardo González-Rodríguez; Ulises Jäuregui‐Haza; Velia Sosa; Patricio J. Espinoza‐Montero
Evaluación del daño renal por cadmio en población expuesta a contaminación por éste en agricultores de Quila-Quila, Potosí
(2020) Carlos Erostegui Revilla; Carla Oporto; Lourdes Zalles; Ricardo Sevilla; Ana Romero
Introduccion: El cadmio es un metal pesado presente en desechos mineros y otros, y tiene efectos deletéreos en la salud humana especialmente en el riñón en el que destruye células tubulares. En una investigación de la calidad del lecho de los ríos que reciben aguas residuales en el norte de Potosí, Bolivia, se reportó presencia de cadmio en papas regadas con esas agua en Quila-quila, una población rural de la zona.El objetivo de ese trabajo fue el de identificar posibles daños del cadmio en la salud de los pobladores de Quila-quila. Metodos: Para ello se realizó revisión clínica y análisis laboratorial clínico y químico de sangre y orina de los pobladores de Quila-quila, y se calculó la tasa de filtración glomerular (TFG) y se correlacionó ésta con indicadores de lesión glomerular. Resultados: Se encontraron niveles elevados de cadmio en sangre en algunas personas, y una correlación de la TFG con la concentración de cadmio en sangre y con indicadores de lesión de membrana glomerular. Conclusiones: En conclusión, los pobladores de Quila-quila estuvieron contaminados por cadmio, el cual produjo lesión renal leve.
EVALUACIÓN DEL POTENCIAL DE Lemna minor PARA LA REMOCIÓN DE Cr (VI) DE AGUAS RESIDUALES
(2001) Carla Oporto; Omar Arce; Niels De Pauw; Erick Van den Broeck
EVALUATION OF THE POTENTIAL OF Lemna minor FOR REMOVING Cr (VI) FROM WASTEWATER Se realizo la evaluacion del potencial de Lemna minor para la remocion de cromo (VI) de aguas residuales. La metodologia de estudio contemplo 3 etapas: (1) Ensayos de laboratorio en reactores batch para identificar variables y obtener datos de parametros que rigen el proceso de remocion de Cr (VI) en un sistema “duckweed”, (2) Desarrollo de un modelo matematico que describe el proceso de remocion y (3) Validacion del modelo matematico propuesto, en un sistema “duckweed” piloto.A partir de los ensayos de laboratorio se analizo el efecto de la presencia de Cr (VI) sobre el crecimiento de Lemna minor y se formulo un modelo conceptual de distribucion del metal en un sistema “duckweed” el cual se utilizo como base para el analisis de los procesos de bioacumulacion y de global. Para ambos procesos se formularon ecuaciones que describen su comportamiento cinetico y se obtuvieron valores para las constantes de velocidad de bioacumulacion y de remocion.La validacion del modelo matematico de remocion de Cr (VI) en un sistema “duckweed' se realizo por comparacion de los resultados de la simulacion con los datos experimentales obtenidos en una planta piloto de 9 reactores en serie con flujo continuo. Palabras clave: duckweed, Lemna minor , Cr (VI), aguas residuales, bioacumulacion. ABSTRACT The potential of Lemna minor for Cr (VI) removal from wastewater was evaluated. The methodology included three phases. First, laboratory tests iin batch reactors were carried out in order to identify variables and to obtain numerical data of parameters governing the removal of Cr (VI) in a duckweed system. Then a mathematical model to describe the Cr (VI) removal process was developed. Finally the proposed mathematical model was validated in a pilot duckweed system.Based on laboratory tests, the effect of Cr (VI) on the growth of Lemna minor was evaluated and a conceptual model of the metal distribution in the system was formulated. This conceptual model allowed analyzing bioaccumulation and overall removal processes. For both processes, equations describing the kinetics were proposed and values for the rate constants were calculated.The mathematical model was validated by comparing the results of the simulation with experimental data from the pilot system that consisted of nine continuous flow reactors connected in series. Key words: Duckweed, Lemna minor Cr (VI), wastewater bioaccumulation.
Experimental study and modelling of Cr (VI) removal from wastewater using Lemna minor
(Elsevier BV, 2006) Carla Oporto; Omar Arce; Eric Van den Broeck; Bart Van der Bruggen; Carlo Vandecasteele
Identifying the cause of soil cadmium contamination with Monte Carlo mass balance modelling: a case study from Potosi, Bolivia
(Taylor & Francis, 2011) Carla Oporto; Erik Smolders; Carlo Vandecasteele
The Chayanta river in Potosi, Bolivia is polluted by present and past mining activities in the districts of Siglo XX and Llallagua. The river water, which is enriched with cadmium (Cd), is used for irrigation in the Quila Quila and Asiruri valleys where the median soil Cd concentration is 20 mg kg(-1), well above the background value of < 0.5 mg kg(-1). The objective of this study was to predict current soil contamination using a retrospective mass balance. Monitoring data were collected on Cd concentrations in irrigation water, irrigation application rates, crop yield and composition, and soil properties including pore water composition. The mass balance was made assuming constant model parameters since the start of upstream mining operations about 85 years ago (1920). The parameter uncertainty was taken into account with a Monte Carlo analysis. The current annual Cd input by irrigation is 800 g ha(-1). The annual output of Cd through removal of the crop harvest and leaching is less than 10 g ha(-1). The predicted soil Cd concentrations after 85 years of contamination (geometric mean: 21.9 mg x kg(-1), 10th and 90th percentile 7.2-65.1 mg kg(-1) respectively) matched the distribution of observed values (geometric mean: 18.6 mg kg(-1); 10th and 90th percentile 4.7-65.9 mg kg(-1) respectively; n = 56). This study confirmed that irrigation water is the prime source of soil Cd enrichment in that area. The Monte Carlo analysis is a convenient way of including parameter uncertainty in mass balance modelling and of estimating spatial variability of the contamination.
Pathogens in crop production systems irrigated with low-quality water in Bolivia
(UWA Publishing, 2018) Luis Fernando Perez-Mercado; Cecilia Lalander; Abraham Joel; Jakob Ottoson; Mercedes Iriarte; Carla Oporto; Björn Vinnerås
In dry areas, the need for irrigation to ensure agricultural production determines the use of all available water sources. However, the water sources used for irrigation are often contaminated by untreated or minimally treated wastewater. Microbial risks from reusing wastewater for vegetable irrigation can be addressed by installing environmental barriers that pathogens must cross to reach humans in the reuse system. Knowledge of pathogen flows inside the system and pathogen removal potential is the first step towards devising a risk management strategy. This study assessed microbe prevalence in farming systems in the Bolivian highlands that use wastewater-polluted sources for irrigation of lettuce. Samples of soil, lettuce and different water sources used in the farming systems were taken during one crop season and concentrations of coliphages, Escherichia coli and helminth eggs were measured. The results showed high spread of these microorganisms throughout the whole system. There was a significant correlation between microbial quality of water and of the harvested produce for several microorganisms. The microbial prevalence in protected shallow wells was found to be significantly lower than in other water sources. These findings can help formulate feasible risk management strategies in contexts where conventional technologies for microbial removal are not possible.