Artículo científico
URI permanente para esta colecciónhttp://10.0.96.45:4000/handle/11056/21283
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Ítem Determinación de los niveles de arsénico presentes en sistemas de abastecimiento de agua de las regiones Chorotega y Huetar Norte de Costa Rica, América Central(Editorial, Universidad Nacional, Costa Rica, 2018) Herrera-Murillo, Jorge; Mora Campos, Diana; Suarez Serrano, Andrea; Chaves Villalobos, María; Salas, J. Pablo; Gamboa-Jiménez, Alejandra; Anchía Leitón, DeivisSe determinaron las concentraciones de Arsénico (As) presentes en muestras de agua para uso y consumo humano recolectadas en 106 operadores comunales de sistemas de abastecimiento en las regiones Chorotega y Huetar Norte de Costa Rica durante 2013-2017. A las muestras que registraron concentraciones de As por encima de la norma nacional se le evaluaron los restantes parámetros incluidos en el nivel N2 del Reglamento para agua potable de Costa Rica. La determinación de arsénico se hizo utilizando espectrometría de absorción atómica con horno de grafito. Los principales incumplimientos se registraron en los distritos de Bagaces y Cañas mientras que en la Región Huetar Norte se presentan en Agua Zarcas y Los Chiles. En estos distritos se registra un nivel de incumplimiento de la norma nacional (10 μg/l) que varía desde 66,7 % en el caso de Los Chiles hasta un 50 % en Cañas. Los sistemas que presentan incumplimientos no registraron variaciones temporales significativas en las concentraciones de As en el periodo 2013-2017. Al analizar los parámetros de correlaciones significativas registradas entre el As y las otras especies analizadas se obtiene información valiosa relacionada con los procesos hidrogeoquímicos que determinan la presencia de este metaloide.Ítem Mining environmental liabilities: a potential source of metal contamination for freshwater ecosystems in Costa Rica(Universidad Nacional, Costa Rica, 2021-03-23) Rojas-Conejo, Johanna; Picado Pavón, Francisco; Suarez Serrano, Andrea; van Gestel, Cornelis A. M.; Golcher-Benavides, Christian; Durán Sanabria, Guillermo A.Metal mining in Costa Rica, and use of toxic substances in this activity, has occasionally resulted in the negligent abandonment of waste structures containing significant amounts of toxic metals. These structures have been exposed to oxidation and weathering, resulting in the environmental release of metals, thus affecting the quality of the surrounding freshwater ecosystems. The objective of the investigation was to determine to what extent the abandoned mining liabilities in Líbano de Tilarán, Guanacaste, are a potential source of metal contamination for the waters, sediments and benthic macroinvertebrates of the San José and Cañas Rivers. The possible consequences for the environment associated with the presence of mining wastes were quantitatively and qualitatively assessed through the amounts of metals present in the wastes and leachate. Infiltration tests were carried out and a wet cell kinetic test allowed describing the processes and chemical reactions that are likely to occur in mining wastes during rain, associated with the loading of metals in leachate. The presence of pyrite (FeS2), which favors the acidification of the medium and the release of metals, was shown by X-ray diffraction tests on samples of the waste materials. The results show a high content of metals (37.8 tons of lead, 20.2 tons of arsenic and 0.4 tons of cadmium) from the total of ~106 tons in mining liabilities, the solubilization of these and other metals in an oxidizing acid medium (pH: 4.16, EC: 3620 µs / cm and ORP: 275 mV) during the dry-rainy season transition and an important load of metals (277 kg / month of zinc, 234 kg / month of magnesium, 165 kg / month of aluminum, 96.1 kg / month of iron, 2.68 kg / month of cadmium, 0.90 kg / month of arsenic and 0.22 kg / month of lead) in leachates arriving to the San José River in September. This investigation showed that the abandoned mining liabilities in Líbano are a potential source of metal contamination for the surrounding freshwater ecosystems.Ítem On the Potential of Biochar Soil Amendments as a Sustainable Water Management Strategy(Universidad Nacional, Costa Rica, 2022-06-08) Lyon, Steve W.; Fischer, Benjamin M. C.; Morillas, Laura; Rojas-Conejo, Johanna; Sánchez-Murillo, Ricardo; Suárez Serrano, Andrea; Frentress, Jay; Cheng, Chih-Hsin; García-San Jose, Monica; Johnson, MarkBiochar has been put forward as a potential technology that could help achieve sustainable water management in agriculture through its ability to increase water holding capacity in soils. Despite this opportunity, there are still a limited number of studies, especially in vulnerable regions like the tropics, quantifying the impacts of biochar on soil water storage and characterizing the impacts of biochar additions on plant water composition. To address this critical gap, we present a case study using stable water isotopes and hydrometric data from melon production in tropical agriculture to explore the hydrological impacts of biochar as a soil amendment. Results from our 10-week growing season experiment in Costa Rica under drip irrigation demonstrated an average increase in volumetric soil moisture content of about 10% with an average moisture content of 25.4 cm3 cm−3 versus 23.1 cm3 cm−3, respectively, for biochar amended plots compared with control plots. Further, there was a reduction in the variability of soil matric potential for biochar amended plots compared with control plots. Our isotopic investigation demonstrated that for both biochar and control plots, there was a consistent increase (or enrichment) in isotopic composition for plant materials moving from the roots, where the average δ18O was −8.1‰ and the average δ2H was −58.5‰ across all plots and samples, up through the leaves, where the average δ18O was 4.3‰ and the average δ2H was 0.1‰ across all plots and samples. However, as there was no discernible difference in isotopic composition for plant water samples when comparing across biochar and control plots, we find that biochar did not alter the composition of water found in the melon plant material, indicating that biochar and plants are not competing for the same water sources. In addition, and through the holistic lens of sustainability, biochar additions allowed locally sourced feedstock carbon to be directly sequestered into the soil while improving soil water availability without jeopardizing production for the melon crop. Given that most of the expansion and intensification of global agricultural production over the next several decades will take place in the tropics and that the variability of tropical water cycling is expected to increase due to climate change, biochar amendments could offer a pathway forward towards sustainable tropical agricultural water management.Ítem ¿Qué pensamos del agua? Percepción de la población sobre la situación actual del recurso hídrico en Costa Rica: un indicador sobre el conocimiento y la gestión del agua(Universidad Nacional, Costa Rica, 2020-01-31) Madrigal-Solís, Helga; Pizarro-Mendez, Yanina ; Jimenez Cavallini, Sylvia; López Alfaro, Nelly; Echeverría-Sáenz, Silvia; Alfaro-Chinchilla, Carolina; Centeno Morales, Jacqueline; Suarez Serrano, AndreaEl objetivo de la presente investigación fue determinar el nivel del conocimiento y la percepción de la población costarricense acerca del agua, para consumo humano, conceptos generales, el impacto de las actividades humanas, la ocurrencia de los eventos extremos, gestión y gobernanza del agua. En el 2016, se realizó un estudio cuantitativo-descriptivo de percepción de población por medio de una encuesta semiestructurada dirigida a 800 personas, a través de llamadas a teléfonos fijos. Se encontró que los costarricenses: a) percibieron que el agua es un bien público y que existe mayor disponibilidad de la que en realidad hay, b) 22 % indicó tener problemas de abastecimiento, infraestructura y/o calidad del agua, c) son conscientes de la contaminación de los cuerpos de agua y, d) percibieron afectación por inundaciones y deslizamientos y, e) 55 % coincidió en que el agua para consumo proviene de pozos y nacientes, pero solo el 12 % y el 36 % tuvo una noción general de lo que es un acuífero y el agua subterránea, respectivamente. Se concluye que los programas de educación deben incluir conceptos generales sobre agua subterránea, gestión y gobernanza del agua y que la anuencia a pagar más por el tratamiento de las aguas residualesÍtem Surface-Water Quality of the Gulf of Papagayo, North Pacific, Costa Rica(Universidad Nacional, Costa Rica, 2021-08-25) Saravia Arguedas, Ana Yury; Vega Bolaños, Hannia; Vargas-Hernández , José Mauro ; Suárez Serrano, Andrea; Sierra Sierra, Luis Manuel; Tisseaux, Alexandre; Cambronero Solano, Sergio; Lugioyo, Gladys MargaritaIn recent years, the northwestern part of the North Pacific areas of Costa Rica has undergone rapid socioeconomic development. This situation, combined with the scarce available information about the water quality of the Gulf of Papagayo, became the starting point to carry out a study to investigate the spatiotemporal variations of physicochemical and biological parameters of surface waters. Seven samplings were collected during the dry season and the rainy season from October 2016 to February 2018. Water quality parameters such as: temperature, salinity, dissolved oxygen, and chlorophyll a of six analytes: nitrate, nitrite, ammonia, phosphate, silicate and biological oxygen demand were measured. The results showed that phosphate and ammonium levels were lower during the rainy season (<6 µg P-PO4−3 L−1–9.53 µg P-PO4−3 L−1 and <11 µg N-NH4+ L−1–9.57 µg N-NH4+ L−1) than during the dry season (<6 µg P-PO4−3 L−1–13.64 µg P-PO4−3 L−1 and <11 µg N-NH4+ L−1–14.43 µg N-NH4+ L−1), which may be related to low rainfall (0, 00–26, 16 mm) during the sampling period. The dry season showed enrichment of ammonium, phosphate, and chlorophyll a due to the influence of the coastal upwelling for the intensification of the Papagayo winds from December to March. The physical, chemical, and biological indicators demonstrated that the Gulf waters had adequate quality. Nonetheless, there are specific areas such as Culebra Bay with conditions that could show deterioration of water quality.