Carrera de Biotecnología

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Subject: search.filters.subject.ARSÉNICO

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    Evaluación del consumo de oxígeno por bacterias aeróbicas en aguas residuales de la planta de tratamiento de Ambato contaminadas con arsénico y cromo
    (Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2023-03) Freire Alegria, Sharon Mayli; Peñafiel Ayala, Rodny David
    Industrial activities and population growth have led to an increase in the use of water resources and, therefore, the generation of wastewater. These have a high pollution load, both biological and non-biological (heavy metals, organic matter). For this reason, the objectives of this curricular integration project were to characterize the wastewater obtained from three secondary treatment points (the clarified effluent from the primary reactor, the mixed liquor from the biological reactor and the biosolids recirculation tank) of the Ambato wastewater treatment plant. Toxicity bioassays were also conducted by adding arsenic and hexavalent chromium, to verify how these metals affect the oxygen uptake rate and the inhibition of 20, 50 and 80 percent of microbial metabolism and growth. Determining that, as the concentration of the elements increased, the oxygen uptake rate decreased in both cases, as they decreased from 277 to 152 (arsenic) and from 288 to 68 milligrams of oxygen per liter per day (chromium). Furthermore, chromium was more toxic than arsenic, since the latter metal needed higher concentrations (1000 milligrams per liter) to achieve a 20 percent inhibition, as opposed to chromium, which needed only 13 milligrams per liter. Finally, these studies have been carried out with the purpose of providing alternatives to optimize wastewater treatment in future research.
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    Determinación de metales pesados en suelos de cultivo y en granos de plantaciones de cacao (Theobroma cacao L.) pertenecientes a la zona litoral central del Ecuador
    (Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2023-03) Albán Ávila, Ostz Garry; Peñafiel Ayala, Rodny David
    Heavy metals such as cadmium (Cd), lead (Pb), nickel (Ni), and arsenic (As) are dangerous to the environment and human health. Recent research has concluded that they are related to health risks caused by the ingestion of contaminated food. This study uses a general approach to determine the concentrations of Cd, Pb, Ni, and As in the cultivated soil and in cocoa beans, which grow in a cocoa plantation in Montalvo - Los Ríos. The main purpose of this study is to determine if the concentrations of heavy metal exceed the maximum permissible limits (MPL) established by environmental standards and international legislation for cocoa and its derivatives. As a result, As and Cd present in the cultivated soil exceeded the MPL of 19 and 0.5 milligrams per kilogram respectively, with mean concentrations of 13.80 milligrams per kilogram of As and 0.69 milligrams per kilogram of Cd. As, Ni and Cd present in cocoa beans exceeded the MPL of 0.5, 1 and 0.1 to 0.8 milligrams per kilogram respectively, with mean concentrations of 3.67 milligrams per kilogram of As, 3.21 milligrams per kilogram of Ni and 1.48 milligrams per kilogram of Cd. Overall, it is necessary to develop successful remediation techniques in the cultivated soil, meanwhile, in cocoa beans, these metals should be considered by public health authorities in the intake of products derived from cocoa.