Browsing by Subject "Water pollution"

Now showing 1 - 3 of 3
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    Degradación de los recursos hídricos en un ambiente semiárido. Las lagunas de Bustillos y de los Mexicanos (Chihuahua, México)
    (2016-06-13) Amado Álvarez, Jesús Pilar; Pérez Cutillas, Pedro; Ramírez Valle, Orlando; Alarcón Cabañero, Juan José
    En la parte central del estado de Chihuahua (México) se encuentra la cuenca de drenaje que alimenta las lagunas endorreicas de Bustillos, y de los Mexicanos. Estos humedales de especial interés ambiental, se encuentran amenazados por una fuerte presión de actividades humanas. Para este trabajo se han planteado una serie de análisis químicos, físicos y microbiológicos, que determinan unos elevados índices de contaminación en estos hábitats acuáticos. Los resultados han mostrado bajos índices de oxígeno disuelto y elevadas concentraciones en nitratos y bacterias coliformes en el agua. Se ha detectado que las principales fuentes de contaminación de estos recursos hídricos son las actividades agropecuarias, los vertidos de aguas residuales de las áreas urbanas y, en mayor medida, por los desechos de los tratamientos industriales.
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    Magnetic core‑modified silver nanoparticles for ibuprofen removal: an emerging pollutant in waters
    (Nature Research, 2020-10-26) Vicente Martínez, Yésica; Solana González, Ruben; Soto Meca, Antonio; Caravaca, Manuel; Química Analítica
    In this work we present a novel procedure for ibuprofen adsorption from waters employing magnetic core-modified silver nanoparticles. We demonstrate that 93% adsorption of ibuprofen is achieved in 45 min by means of a simple method, for neutral pH and room temperature, also using a low dose of adsorbent, equal to 7 mg in 500 �L of suspension. The characterization of the adsorbent, before and after adsorption, was carried out by means of field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, BET analysis, Fourier-transform infrared spectroscopy and differential scanning calorimetry. It is worth pointing out that ibuprofen can be desorbed and the adsorbent can be reused, remaining unaltered for the first three cycles, and showing 89.3% adsorption efficiency after the third regeneration. A three-parameter model and the Langmuir isotherm characterize the kinetics and isotherm of adsorption.
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    Mercury accumulation, structural damages, and antioxidant and immune status changes in the Gilthead Seabream (Sparus aurata L.) exposed to methylmercury
    (Springer, 2016-02-23) Chaves-Pozo, E.; Espinosa, C.; Romero, D.; Meseguer, J.; Cuesta Peñafiel, Alberto; Esteban Abad, María de los Ángeles; Guardiola Abellán, Francisco Antonio; Ciencias Sociosanitarias
    In aquatic systems, mercury (Hg) is an environmental contaminant that causes acute and chronic damage to multiple organs. In fish, practically all of the organic Hg found is in the form of methylmercury (MeHg), which has been associated with animal and human health problems. This study evaluates the impact of waterborne-exposure to sublethal concentrations of MeHg (10 [mu]g L^sup -1^) in gilthead seabream (Sparus aurata). Hg was seen to accumulate in liver and muscle, and histopathological damage to skin and liver was detected. Fish exposed to MeHg showed a decreased biological antioxidant potential and increased levels of the reactive oxygen molecules compared with the values found in control fish (nonexposed). Increased liver antioxidant enzyme activities (superoxide dismutase and catalase) were detected in 2 day-exposed fish with respect to the values of control fish. However, fish exposed to MeHg for 10 days showed liver antioxidant enzyme levels similar to those of the control fish but had increased hepato-somatic index and histopathological alterations in liver and skin. Serum complement levels were higher in fish exposed to MeHg for 30 days than in control fish. Moreover, head-kidney leukocyte activities increased, although only phagocytosis and peroxidase activities showed a significant increase after 10 and 30 days, respectively. The data show that 30 days of exposure to waterborne MeHg provokes more significant changes in fish than a short-term exposure of 2 or 10 days.