Browsing by Author "Jara Negrete, Eliza Nuit"

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Adsorption of estradiol by natural clays and Daphnia magna as biological filter in an aqueous mixture with emerging contaminants
(2021) Cipriani Ávila, Eva Isabel; Capparelli, Mariana V.; Jara Negrete, Eliza Nuit; Alvarado Martínez, Andrés Omar; Cisneros Ramos, Juan Fernando; Tripaldi, Piercosimo; Perez Gonzalez, Bolivar Andres; Pinos Vélez, Verónica Patricia
Among emerging pollutants, endocrine disruptors such as estradiol are of most concern. Conventional water treatment technologies are not capable of removing this compound from water. This study aims to assess a method that combines physicochemical and biological strategies to eliminate estradiol even when there are other compounds present in the water matrix. Na-montmorillonite, Ca-montmorillonite and zeolite were used to remove estradiol in a medium with sulfamethoxazole, triclosan, and nicotine using a Plackett–Burman experimental design; each treatment was followed by biological filtration with Daphnia magna. Results showed between 40 to 92% estradiol adsorption in clays; no other compounds present in the mixture were adsorbed. The most significant factors for estradiol adsorption were the presence of nicotine and triclosan which favored the adsorption, the use of Ca-montmorillonite, Zeolite, and time did not favor the adsorption of estradiol. After the physicochemical treatment, Daphnia magna was able to remove between 0–93% of the remaining estradiol. The combination of adsorption and biological filtration in optimal conditions allowed the removal of 98% of the initial estradiol concentration.
Emerging contaminants in the northeast andean foothills of Amazonia: the case of study of the city of Tena, Napo, Ecuador
(2021) Pérez González, Andrés ; Pinos Vélez, Verónica Patricia; Molinero, Jon; Capparelli, Mariana V.; Cipriani Ávila, Eva Isabel; Jara Negrete, Eliza Nuit; Acosta López, Sofía Paola; Acosta, Byron
This work is a study on the occurrence of emerging pollutants in the northeast Ecuadorian Amazon. Emerging contaminants (ECs)—caffeine, triclosan, estradiol, acetaminophen, nicotine, and ibuprofen—were quantified by gas chromatography–mass spectrometry in rivers and streams of the Amazon basin near the city of Tena, Ecuador. For that, a total of 16 natural water samples were taken in 8 locations. Sampling sites included areas impacted by discharges from inefficient sewage networks in urban areas, wastes from fish farming and non-functional landfill, a stream with few threats, tap water, and treated sewage. Caffeine was found in the 38% of the samples studied while trimethoprim and acetaminophen had an occurrence of 13%. Caffeine was detected at two sites receiving untreated sewage and one site receiving treated sewage with mean concentrations that ranged between 19 and 31.5 μg L−1. Acetaminophen (50.4 μg L−1) and trimethoprim (2 μg L−1) were only detected in the river receiving treated sewage effluent. This is the first assessment of emerging contaminants in the upper Ecuadorian Amazon basin, and our observations highlight the need for better sewage treatment and water quality monitoring in Amazonian cities.