Química
Envíos recientes
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Fisico-química de las aguas superficiales de la Cuenca del río Rincón, Península de Osa, Costa Rica
(2010-12)The Rincon River Basin is characterized by steep and rugged topography with outcrops of recent sediments as well as igneous and sedimentary rocks. The area is mostly covered by forest (Tropical Wet Forest) and agricultural ... -
The role of chloramine species in NDMA formation
(2018-09)N-nitrosodimethylamine (NDMA), a probable human carcinogen disinfection by-product, has been detected in chloraminated drinking water systems. Understanding its formation over time is important to control NDMA levels in ... -
Removal of both N-nitrosodimethylamine and trihalomethanes precursors in a single treatment using ion exchange resins
(2017-11-01)Drinking water utilities are relying more than ever on water sources impacted by wastewater effluents. Disinfection/oxidation of these waters during water treatment may lead to the formation of several disinfection ... -
Design of an optimized biomixture for the degradation of carbofuran based on pesticide removal and toxicity reduction of the matrix
(2015-12)Pesticide biopurification systems contain a biologically active matrix (biomixture) responsible for the accelerated elimination of pesticides in wastewaters derived from pest control in crop fields. Biomixtures have been ... -
Pristine but metal-rich Río Sucio (Dirty River) is dominated by Gallionella and other iron-sulfur oxidizing microbes
(2017-03)Whether the extreme conditions of acidity and heavy metal pollution of streams and rivers originating in pyritic formations are caused primarily by mining activities or by natural activities of metal-oxidizing microbes ... -
Metals in coastal mollusks of Costa Rica
(2015-12)The input of contaminants to coastal ecosystems is a global problem on the rise. Data on metal pollution from tropical sites is often lacking and pilot surveys are urgently needed to provide a general framework to estimate ... -
Ecotoxicological analysis during the removal of carbofuran in fungal bioaugmented matrices
(2016-02)Biomixtures are used for the removal of pesticides from agricultural wastewater. As biomixtures employ high content of lignocellulosic substrates, their bioaugmentation with ligninolytic fungi represents a novel approach ... -
Influence of rice field agrochemicals on the ecological status of a tropical stream
(2016-01-15)Many tropical countries contain a high density of protected ecosystems, and these may often be bordered by intensive agricultural systems. We investigated the chemical and ecological status of a stream connecting an area ... -
Analysis of glyphosate and aminomethylphosphonic acid in leaves from Coffea arabica using high performance liquid chromatography with quadrupole mass spectrometry detection
(2016-01-01)Glyphosate is a commonly applied herbicide in coffee plantations. Because of its non-selective mode of action it can damage the crop exposed through spray drift. Therefore, it is of interest to study glyphosate fate in ... -
Removal of N-nitrosodimethylamine precursors with powdered activated carbon adsorption
(2016-01-01)The main objective of this study was to examine the roles of powdered activated carbon (PAC) characteristics (i.e., surface chemistry, pore size distribution, and surface area) in the removal of N-nitrosodimethylamine ... -
Evaluation of a recent product to remove lipids and other matrix co-extractives in the analysis of pesticide residues and environmental contaminants in foods
(2016-06-03)This study demonstrates the application of a novel lipid removal product to the residue analysis of 65 pesticides and 52 environmental contaminants in kale, pork, salmon, and avocado by fast, low pressure gas chromatography ... -
Granular Activated Carbon Treatment May Result in Higher Predicted Genotoxicity in the Presence of Bromide
(2016-07-28)Certain unregulated disinfection byproducts (DBPs) are more of a health concern than regulated DBPs. Brominated species are typically more cytotoxic and genotoxic than their chlorinated analogs. The impact of granular ... -
Room temperature gas-solid reaction of titanium on glass surfaces forming a very low resistivity layer
(2016-09)Titanium films were deposited on quartz, glass, polyamide and PET substrates in a high vacuum system at room temperature and their electrical resistance monitored in vacuo as a function of thickness. These measurements ... -
Detection of the adsorption of water monolayers through the ion oscillation frequency in the magnesium oxide lattice by means of low energy electron diffraction
(2016-03)We investigate the variation of the oscillation frequency of the Mg2+ and O2− ions in the magnesium oxide lattice due to the interactions of the surface with water monolayers by means of Low Energy Electron Diffraction. ... -
A Metabolic Widget Adjusts the Phosphoenolpyruvate-Dependent Fructose Influx in Pseudomonas putida
(2016)Fructose uptake in the soil bacterium Pseudomonas putida occurs through a canonical phosphoenolpyruvate (PEP)-dependent sugar transport system (PTSFru). The logic of the genetic circuit that rules its functioning is puzzling: ...
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