Alternative methods for the treatment of environmental contamination with heavy metal

En la actualidad, diversos ambientes acuáticos naturales se encuentran contaminados por metales pesados y/o pesticidas producto del desarrollo industrial y agrícola de las últimas décadas. Los diversos métodos de depuración de efluentes contaminados en uso no siempre son efectivos y en general presentan altos costos de aplicación, por lo que es necesario desarrollar técnicas eficientes, de fácil aplicación, económicas y por sobre todo sustentables con el medio ambiente. En la presente tesis se evaluaron las capacidades de adsorción de dos macroalgas marinas (Ulva lactuca y Gymnogongrus torulosus), una maleza (Avena fatua) y una microalga de agua dulce (Asterococcus limneticus) como posibles biosorbentes de plomo, cadmio, cobre y zinc; así como la adsorción de Glifosato por U. lactuca. También se estudió el efecto de la presencia de estos metales en el crecimiento de A. fatua, siendo el cobre y el zinc los metales que afectan el crecimiento de la maleza, mientras que el cadmio y el plomo presentan alta afinidad por las partículas orgánicas de los suelos quedando menos biodisponibles para la planta. Las eficiencias de remoción de los distintos sustratos fueron determinadas en función del pH, la temperatura, el tiempo de contacto y las concentraciones iniciales de los distintos sorbatos. Los modelos de Langmuir, Freundlich, Temkin y Dubinin- Radushkevich fueron aplicados a los resultados experimentales, siendo el modelo de Langmuir el que mejor describe la adsorción en todos los casos analizados. Las capacidades de adsorción aumentan con el pH y la energía libre del proceso muestra que el sistema es espontáneo. Los estudios cinéticos demostraron que la adsorción de los distintos sorbatos sigue una cinética de pseudo segundo orden para la mayoría de los casos estudiados. Las eficiencias de remoción de los biomateriales soportados en matrices de agar y de HDPE se midieron y los resultados se compararon con los obtenidos para las suspensiones. Por último se evaluó la eficiencia de retención de U. lactuca empaquetada en columnas.Nowadays, many natural aquatic environments are contaminated by heavy metals and / or pesticides due to industrial and agricultural development during the recent decades. Purification methods for contaminated effluents actually in use are not always effective and generally have high implementation costs, making necessary to develop efficient techniques, easy to apply, economic and environmentally sustainable. In this PhD Dissertation the adsorption capacities of two marine macroalgae (Ulva lactuca and Gymnogongrus torulosus), a weed (Avena fatua) and a freshwater microalga (Asterococcus limneticus), were evaluated as potential biosorbents for lead, cadmium, copper and zinc, as well as the adsorption of glyphosate by U. lactuca. The effects of the presence of these metals in the growth of A. fatua were also studied. Results demonstrated that copper and zinc affect the growth of this weed, while cadmium and lead have high affinity for soil organic particles being less bioavailable for the plant. The removal efficiencies of the different substrates were determined as a function of pH, temperature, contact time and initial concentrations of the different sorbates. Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models were applied to the experimental results, and based on the results Langmuir model best describes the adsorption in all cases analyzed. The adsorption capacity increases with pH and free energy of the process shows that the system is spontaneous. Kinetic studies showed that, in most cases studied, the adsorption of different sorbates follows a pseudo second order kinetics. Removal efficiencies of biomaterials supported in agar and HDPE matrices were measured and results were compared with those obtained for batch mode. Finally, adsorption efficiency for U. lactuca packed in columns we evaluated.Fil:Areco, María del Mar. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Copper, zinc, cadmium and lead biosorption by Gymnogongrus torulosus. Thermodynamics and kinetics studies

Gymnogongrus torulosus adsorption efficiency for cadmium(II), copper(II), lead(II) and zinc(II) were studied in batch mode in different acidic conditions. The adsorbent removal efficiency was determined as a function of contact time, initial metal ions concentration, pH and temperature. G. torulosus was characterized by SEM, water adsorption surface area and EDS. The Langmuir, Freundlich, Dubinin-Radushkevich and Temkin models have been applied and results showed that the biosorption process was better described by the Langmuir model. Kinetic experiments demonstrated that fast metal uptakes follow a pseudo-second-order kinetic model and that intra-particle diffusion and/or chemisorption were the rate-limiting steps. Experimental results show that G. torulosus isotherm followed the biosorption series, Cu > Cd ∼ Zn ∼ Pb. Biosorption capacities were affected by solution parameters. The maximum metal uptake (qmax) increased with increasing pH. The affinity constant, qmax, and the pseudo-second-order kinetic constants were calculated for the adsorption of all studied metals onto G. torulosus. The Gibbs free energy of the adsorption process as well as the process enthalpy and entropy were calculated from experimental results.Fil: Areco, María del Mar. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Física de los Materiales, Medio Ambiente y Energía ; ArgentinaFil: Dos Santos Afonso, María. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Física de los Materiales, Medio Ambiente y Energía ; Argentin

Datos paper "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 photosynthesisrespiration 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, María del Mar. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Haug, Erika. Universidad Nacional de San Martín. Instituto de Investigación en Ingeniería Ambiental; ArgentinaFil: Curutchet, Gustavo Andres. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentin

Microplastic pollution in marine environments: Exploring sources, sinks, and consequences with a focus on algal interactions

The widespread use of plastics and their low recycling rate has led to a very serious environmental problem, as plastics accumulate at an alarming rate, with effects that have not yet been thoroughly studied. Due to their small size, microplastics have become ubiquitous in various ecosystems. Furthermore, they enter organisms through multiple pathways, posing a threat to different species. The interaction between microplastics and algae, fundamental elements of aquatic food chains, has significant implications for the overall health of ecosystems. This review analyses the information published in scientific articles and official reports on the occurrence and effects of microplastics in the marine environment, particularly on algae, and their potential use for microplastic remediation. Results published demonstrate that despite the locations, it may seem that microplastics are present in all types of environments around the world. They are accumulated in sediments, seagrass, and throughout the food web. In marine environments, polyethylene is the most common polymer found, followed by polypropylene, with fibres and fragments being the most common forms. Several papers report different alga-microplastic interactions. These interactions offer opportunities for potential solutions to marine plastic pollution, as they could be used in the remediation of microplastics, due to their high adsorption capacity. However, extensive research is needed to determine the most suitable algal species, optimal conditions, practical challenges, and potential risks associated with this phycoremediation approach. The main gap in the literature is that current research often lacks precision in quantifying microplastic concentrations, which hinders the ability to accurately assess the associated risks, particularly to edible species. To address these challenges, the development of standardized protocols and reliable analytical techniques is essential. Urgent and systematic research on microplastics is needed to understand their sources, distribution, impacts and risks, to inform environmental and human health policies, and promote sustainable alternatives to plastics.Fil: Salomone, Vanesa Natalia. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Passucci, Victoria. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Areco, María del Mar. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería 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, María del Mar. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Haug, Erika. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Curutchet, Gustavo Andres. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentin

Nitrogen source uptake and associated pH changes influence growth and biomass composition in microalgae isolated from a polluted river

Microalgae exhibit diverse responses to various nitrogen forms in natural environments, affecting growth rates, biomass yields, composition, by-product production, and nutrient utilization efficiency, which vary among species and strains. In the present study, the growth of two microalgae species was investigated with different nitrogen sources to study their effect on these parameters. In particular, the evolution of several parameters associated with microalgal cultures was examined in relation to the nitrogen source and the pH of the culture medium. Furthermore, simple alternative techniques for estimating biomass growth in microalgal cultures based on nitrogen consumption and/or acid/base titrations are proposed. CI (Parachlorella kessleri) and DIII (Desmodesmus communis) were isolated from the Reconquista River, a polluted watercourse in Buenos Aires, Argentina. CI showed higher productivity, faster biomass growth, and increased extracellular polymeric substances (EPS) production, which promoted cell agglomeration, when cultured in culture medium with NO3- as the nitrogen source, compared to cultures with NH4+ as the nitrogen source. On the other hand, DIII grew only when cultured in medium with NO3-, reaching a maximum growth rate comparable to that of CI in culture medium with NO3-. Growth inhibition in cultures containing NH4+ was attributed to pH decrease associated with NH4+ uptake rather than NH4+ effects. Both species exhibited an increase in the C/N ratio. Under N starvation DIII accumulates N-free substances like lipids and starch in both culture conditions, at controlled pH (≈7). In contrast, the results for CI showed a more pronounced increase in the C/N ratio when cultured in medium containing NO3-, which was attributed to the formation of EPS. These variations in the composition of the microalgae biomass and the occurrence of cellular agglomeration throughout a culture suggest that different biomass estimation techniques may not be directly comparable across different phases of a culture. In this sense, in the present work it was demonstrated that for certain conditions, it is possible to accurately estimate growth from the consumption of nitrogen, and from the variation in the concentration of OH- and/or H+ of the culture medium.Fil: Passucci, Victoria. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Areco, María del Mar. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Ferraro, Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Curutchet, Gustavo Andres. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentin

Copper removal by Botryococcus braunii biomass with associated production of hydrocarbons

The goal of the present article is to evaluate the potential of copper(II) removal from acidic wastewater, associated with the production of hydrocarbons by the microalgae Botryococcus braunii. Results demonstrate that the growth of B. braunii is correlated with the hydrocarbon production as well as with alcalinization and copper removal from the medium. Even though B. braunii did not present high rates of copper adsorption, the increase in the pH of the media promotes the precipitation of the metal. In this way copper can be removed from solution by both, adsorption and precipitation. Results suggest that metabolic active biomass of B. braunii could be used for copper removal from solution while it produces appreciable quantities of hydrocarbons. This fact is very interesting in order to develop new remediation processes of waste water with coupled energy productionFil: Areco, María del Mar. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Cainzos, Verónica Jorgelina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Curutchet, Gustavo Andres. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentin

Ulva Lactuca: Adsorption, Bioaccumulation and Remediation

Pollution of natural waters has become a major issue all over the world. As a result, scientists are studying new and alternative technologies not only to identify the presence of different pollutants in the environments but to remove them from waters and industrial effluents. In these senses, in recent years various red, green and brown seaweeds were investigated as potential bioindicators of contaminants inthe environment; as well as their use in remediation process. The green marine macroalga, Ulva lactuca (Chlorophyta) is very common at coastal areas, and is a bloom forming macroalgae that occur in shallow estuaries. This specie has a high bonding affinity with heavy metals and several organic compounds due to the presence of different functional groups on its cell walls (such as carboxyl, hydroxyl, phosphate or amine) that can bind metal and/or organic ions. These characteristics makes it suitable to be used as a bioindicator of marine pollution and for remediation purposes. In general, the investigations are focused on the application of dried algae biomass to promote the removal of different contaminants, mainly metals from aqueous solutions (biosorption); however, the use of living organisms (bioaccumulation), may be advantageous. While growing, living macroalgae can remove simultaneously pollutants and nutrients (nitrates and phosphates) from wastewaters and capture CO2 emissions. In this context, the present chapter will conduct a comprehensive inquiry on the advances related to the possibility of Ulva lactuca to be used as a bioindicator of contamination as well as its capability to be employed for the removal of pollutants from the surrounding environment. It will review these different approaches, and analyse the advantages and disadvantages of each as exposed on the literature, as well as the challenges that these alternatives confront as sustainable remediations technologies.Fil: Areco, María del Mar. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Salomone, Vanesa Natalia. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Dos Santos Afonso, María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin

Asterococcus superbus as a biosorbent of copper, zinc, cadmium and lead: adsorption isotherm and kinetic modelling

The adsorption capacity of copper, zinc, cadmium and lead by Asterococcus superbus, a freshwater microalgae, was studied in batch mode. The Langmuir, Freundlich, Temkin and Dubinin?Radushkevich models were applied and results demonstrate that for all cases the Langmuir model best describes the adsorption process and that A. superbus isotherm followed the bisorption series, Zn > Cu > Pb > Cd. Kinetic studies demonstrate that the adsorption of zinc and copper follows a pseudo-second-order kinetic model, and that of cadmium and lead follows a pseudo first-order kinetic model. Natural waters present an increasing concentration of heavy metals, mainly due to the effluent discharge in these type or reservoires. The importance of the present work is to contribute to the study of new methods to diminish the presence of heavy metals in natural waters.Fil: Areco, María del Mar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Rodriguez, Maria Cecilia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Dos Santos Afonso, María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin

Ulva lactuca: A bioindicator for anthropogenic contamination and its environmental remediation capacity

Coastal regions are subjected to degradation due to anthropogenic pollution. Effluentsloaded with variable concentrations of heavy metal, persistent organic pollutant, as wellas nutrients are discharged in coastal areas leading to environmental degradation. Inthe past years, many scientists have studied, not only the effect of differentcontaminants on coastal ecosystems but also, they have searched for organismstolerant to pollutants that can be used as bioindicators or for biomonitoring purposes.Furthermore, many researchers have demonstrated the capacity of different marineorganisms to remove heavy metals and persistent organic pollutants, as well as toreduce nutrient concentration, which may lead to eutrophication. In this sense, Ulvalactuca, a green macroalgae commonly found worldwide, has been extensivelystudied for its capacity to accumulate pollutants; as a bioindicator; as well as for itsremediation capacity. This paper aims to review the information published regardingthe use of Ulva lactuca in environmental applications. The review was focused onthose studies that analyse the role of this macroalga as a biomonitor or inbioremediation experiments.Fil: Areco, María del Mar. Universidad Nacional de San Martín. Instituto de Investigación en Ingeniería Ambiental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Salomone, Vanesa Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Instituto de Investigación en Ingeniería Ambiental; ArgentinaFil: Dos Santos Afonso, María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin