Determination of biosorption mechanism in biomass of agave, using spectroscopic and microscopic techniques for the purification of contaminated water

[Abstract] Lead (Pb2+) and copper (Cu2+) are polluting metals due to their toxicity; however, the extraction of these metals is essential for economic development, so it is important to look for efficient and low-cost alternatives that can remove heavy metals from the various bodies of water. One of the alternatives used in this work is biosorption, for which an agroindustrial waste (epidermis from Agave atrovirens) was used to evaluate the affinity of removal of lead and copper in aqueous solutions; in addition, spectroscopy and microscopy techniques were used to elucidate and corroborate the removal and affinity capacity of the agave epidermis for both metals studied. The optimal pH value for the removal of both metals was 3. The adsorption isotherms yielded a qmax of 25.7 and 8.6 mg/g for lead and copper, respectively. Adjusting to the Langmuir-Freundlich model, the adsorption kinetics were pseudo-second order, and it was found that the equilibrium time was at 140 min. The spectroscopy and microscopy analyses corroborated the affinity between metals and functional groups of the agave, as well as with the elemental analysis, which reported 17.38% of lead and 4.25% of copper.[Resumen] El plomo (Pb2+) y el cobre (Cu2+) son metales contaminantes debido a su toxicidad; sin embargo, la extracción de estos metales es indispensable para el desarrollo económico, por lo que es importante buscar alternativas eficientes y de bajo costo que puedan remover metales pesados de los diversos cuerpos de agua. Una de las alternativas utilizadas en este trabajo es la biosorción, para la cual se utilizó un residuo agroindustrial (epidermis de Agave atrovirens), para evaluar la afinidad de remoción del plomo y cobre en soluciones acuosas; adicionalmente, se emplearon técnicas de espesctroscopía y microscopía que permitieron elucidar y corroborar la capacidad de remoción y afinidad que tuvo la epidermis de A. atrovirens para ambos metales estudiados. El valor óptimo de pH para la remoción de ambos metales fue 3. Las isotermas de adsorción arrojaron una qmax de 25.7 y 8.6 mg/g para el plomo y cobre, respectivamente. Ajustando al modelo de Langmuir-Freundlich, las cinéticas de adsorción resultaron de pseudo-segundo orden, se encontró que el tiempo de equilibrio es a los 140 min. El análisis espectroscópico y microscópico, corroboró la afinidad entre metales y grupos funcionales del agave, así como con el análisis elemental, el cual reportó 17.38% de plomo y 4.25% de cobre

Simulating Tritrophic Interactions by Means of P Systems

P systems provide a high level computational modelling framework that combines the structural and dynamical aspects of ecosystems in a compressive and relevant way. The inherent randomness and uncertainty in biological systems is captured by using probabilistic strategies. The design of efficient simulation algorithms in order to reproduce the behavior of these computational models over conventional computers is fundamental for the validation and virtual experimentation processes. In this paper, we describe the modelling framework and two different simulation algorithms. As a case study, a P system based model of an ideal ecosystem with three trophic levels is designed and simulated by both simulation algorithms, providing comparisons of efficiency between them

Comparing simulation algorithms for multienvironment probabilistic P systems over a standard virtual ecosystem

Membrane Computing has recently proved to be a suitable framework for addressing the modelling of dynamical biological systems in general, and ecosystems in particular. Due to the inherent randomness and uncertainty in biological systems, when designing a model the relevant tasks to be addressed are the validation and virtual experimentation processes, rather than the formal verification. It is therefore crucial to rely on software implementations of efficient simulation algorithms. This paper presents a simple (but realistic enough) ecosystem where a carnivore and several herbivorous species interact. The model of this ecosystem has been used to compare experimentally the performance of two different simulation algorithms.Ministerio de Ciencia e Innovación TIN2009–13192Junta de Andalucía P08-TIC-0420

Los mamíferos salvajes terrestres como bioindicadores: nuevos avances en Ecotoxicología

Ecotoxicology as science pretends to correctly identify problems associated to the presence and the effect of chemical substances in the environmental and the wildlife. In this field, the presence of heavy metals on ecosystems constitutes a serious problem, for both their elevated environmental persistence and high toxicity for wildlife. In this sense, the present paper shows a review concerning more recent advances in the modern biomonitoring methodologies, using wild mammals and making differences between destructive and non-destructive methods. L’Ecotoxicologie comme science cherche identifier correcte des problèmes dérivés de la présence et effet des substances chimiques dans l’environnement et les êtres vivants. Dans ce domaine, la présence des métaux lourds dans les écosystèmes constitue un problème très sérieux, pour son élevé persistance environnementale et son haute toxicité pour tous les organismes vivants. Dans ce sens, le présent travaille fait une révision à propos des progrès dans les modernes méthodologies de biomonitoring, avec l’emploie des mammifères sauvages et en faisant une distinction à la méthodologie employee (méthodes destructives et non destructives).La Ecotoxicología como ciencia busca identificar adecuadamente los problemas derivados de la presencia y efecto de sustancias químicas en el medio ambiente y los seres vivos. Dentro de este campo, la presencia de metales pesados en los ecosistemas constituye un serio problema, tanto por su elevada persistencia medioambiental como por su alta toxicidad para todos los organismos vivos. En este sentido, el presente trabajo realiza una revisión sobre los avances más recientes ocurridos en las modernas metodologías de biomonitorización, empleando para ello mamíferos salvajes y haciendo distinción en la metodología empleada (métodos destructivos y no destructivos)

MeCoSim: A general purpose software tool for simulating biological phenomena by means of P Systems

In recent years, the increasing importance of the computational systems biology is leading to an impressive growth of the knowledge of several real-life phenomena. In this framework, membrane computing is an emergent branch within natural computing that has been succesfully used to model biological phenomena. The study of these phenomena usually requires the execution of virtual experiments using mechanisms of simulation, implying the development of ad-hoc tools to simulate. However, the advance of the research is demanding general solutions to avoid the necessity of custom software developments for each matter of study, when there are some common problems to resolve. MeCoSim (Membrane Computing Simulator) is a first step in this direction providing the users a customizable application to generate custom simulators based on membrane computing by simply writing a configuration file.Ministerio de Educación y Ciencia TIN2009–13192Junta de Andalucía P08–TIC-0420

A P System Based Model of an Ecosystem of Some Scavenger Birds

The Bearded Vulture (Gypaetus Barbatus) is an endangered species in Eu- rope that feeds almost exclusively on bone remains provided by wild and domestic ungu- lates. In [1], we presented a P system in order to study the evolution of these species in the Pyrenees (NE Spain). Here, we present a new model that overcomes some limitations of the previous work incorporating other scavenger species (predatory) and additional prey species that provide food for the scavenger intraguild and interact with the Bearded Vulture in the ecosystem. After the validation, the new model can be a useful tool for the study of the evolution and management of the ecosystem. P systems provide a high level computational modelling framework which integrates the structural and dynamical aspects of ecosystems in a compressive and relevant way. The inherent randomness and uncertainty in ecosystems is captured by using probabilistic strategies.Ministerio de Educación y Ciencia TIN2006-13425Junta de Andalucía P08–TIC-0420