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Investigating natural attenuation of pharmaceuticals through unsaturated column tests
No full textThe growing consumption of pharmaceuticals together with their incomplete removal in wastewater treatment plants (WWTPs) implies the occurrence of these compounds in natural water resources. To investigate the natural attenuation of selected pharmaceuticals (caffeine, acetaminophen, sulfamethoxazole, naproxen and carbamazepine) during vadose zone infiltration, unsaturated column (L 26.67 cm, Ø 7.62 cm) experiments, filled with a sandy-loamy soil, were performed using two input concentrations (100 and 1000 μg L−1). The software Hydrus 1D was used to simulate experimental data. Caffeine and acetaminophen were never detected at the column outlet indicating a low environmental concern. On the other hand, attenuation of the detected pharmaceuticals could be reproduced by a combination of retardation and removal approaches. Carbamazepine is among the selected contaminants the most persistent. A dependence of removal rates on input concentrations was detected for sulfamethoxazole (μw from 2.78 d−1 to 1.16 d−1) and naproxen (μw from 1.16 d−1 to 0.63 d−1) attributed mainly to decreased metabolism of microorganisms when a higher input concentration is applied. Two transformation products (TPs) (N4-Acetylsulfamethoxazole and epoxycarbamazepine) derived from sulfamethoxazole and carbamazepine transformation, respectively, were detected during the experiment with the highest input concentration
Ice caves fauna
No full textIce caves are extreme environments where low temperatures significantly contribute in shaping the structural pattern of terrestrial and aquatic biocoenosis. Extreme dwellers inhabiting ice caves range from troglobiotic beetles to stygobites, crustaceans, insects and acarina which show resistance to low temperatures. Many species are rare and endemics strictly tied to cold microclimates habitat conditions. We here provide a review of the environmental settings, habitats and recent and extant fauna in ice caves from Europe, Canada and North America
Merging microbial electrochemical systems with electrocoagulation pretreatment for achieving a complete treatment of brewery wastewater
No full textThe limitations of microbial electrochemical technologies (METs) for full-scale wastewater treatment suggest the need for supporting these systems with a complementary technology. In this study we propose the integration of two electrochemical techniques to fully treat brewery effluents: an electrocoagulation (EC) and a microbial electrochemical fluidized bed reactor (ME-FBR). The EC pretreatment effectively removed most of the suspended matter and the nutrients of the effluent. We investigated the influence of current density and the reaction time on the EC performance. Varying these parameters allowed to fine-tune the removal of nutrients in this first treatment stage, obtaining removals from 30 to 98% of nitrogen and from 25 to 99% of phosphorus. The effluent of the EC was continuously fed into a ME-FBR (organic loading rate of 1.15 kg-COD m−3·d−1) with a fluidized and polarized anode (0.2 V vs Ag/AgCl) colonized with electroactive biofilm. This second step oxidized the soluble organic matter using a fluidized anode as terminal electron acceptor and harvesting current density values of 25 A m−3NRV. With this novel technological tandem, it was possible to remove a 93% of nitrogen, 98% of phosphorus, 93% of the total suspended solids, and >88% of the COD of a brewery wastewater
Morphological design of alumina hollow fiber membranes for desalination by air gap membrane distillation
No full textThe planktonic relationship between fluid-like electrodes and bacteria: wiring in motion
No full textWe have explored a new concept in bacteria-electrode interaction based on the use of fluid-like electrodes and planktonic living cells. We show for the first time that living in a biofilm is not a strict requirement for Geobacter sulfurreducens to exchange electrons with an electrode. The growth of planktonic electroactive G. sulfurreducens could be supported by a fluid-like anode as soluble electron acceptors and with electron transfer rates similar to those reported for electroactive biofilms. This growth was maintained by uncoupling the charge (catabolism) and discharge (extracellular respiration) processes of the cells. Our results reveal a novel method to culture electroactive bacteria in which every single cell in the medium could be instantaneously wired to a fluid-like electrode. Direct extracellular electron transfer is occurring but with a new paradigm behind the bacteria–electrode interaction
Los mapas antiguos y su adecuación como base cartográfica para la valoración del Patrimonio Hidráulico de la Comunidad de Madrid
No full textLa cartografía antigua se considera una base de información, relativamente fidedigna, de cómo estaba constituido el territorio en un época determinada, revelando aspectos relacionados tanto con el hombre como con la naturaleza. Esta investigación, desarrollada en la Comunidad de Madrid y empleando los mapas antiguos elaborados por el Instituto Geográfico Nacional entre 1870 y 1950 aproximadamente, ha demostrado la adecuación del empleo de esta cartografía como base de información para la creación de un inventario del Patrimonio Hidráulico histórico de la Comunidad. La adecuación de estos mapas se ha determinado por medio de los análisis de calidad cartométrica de los mismos para la zona analizada, aproximando unos valores de precisión posicional y temática específicos. El patrimonio hidráulico se define como el conjunto de elementos materiales, inmateriales y simbólicos que combinan el trabajo del hombre y la naturaleza y que muestran el uso que las distintas comunidades han realizado de los recursos hídricos en un territorio concreto. Este trabajo ha confirmado que existe una gran cantidad y variedad de elementos hidráulicos patrimoniales distribuidos por toda la región como demuestra la base de datos espacial y temática elaborada sobre el Patrimonio Hidráulico de la Comunidad de Madrid. Estos elementos se encuentran en muy diferentes estados de conservación, aunque localizados principalmente en las zonas de regadío tradicional (las vegas de los ríos más importantes de la región) y en las zonas metropolitanas dónde existía mayor concentración demográfica. Además, este trabajo ha constatado la fragilidad y elevado grado de amenazas al que están sometidos este tipo de bienes, ya que han desaparecido más del 65% de todos los elementos patrimoniales identificados en los mapas antiguos. La evolución histórica es aún más preocupante en las zonas urbanas, dónde el proceso de expansión de las ciudades ha generado la desaparición de más del 70% de los elementos hidráulicos históricos. Se ha demostrado que aquellos elementos patrimoniales que aún poseen una funcionalidad, sea la original u otra diferente, se encuentran en un mejor estado de conservación que los que han quedado sin utilidad. El inventario realizado y los diferentes análisis llevados a cabo han permitido generar un diagnóstico inicial del estado de los bienes hidráulicos en la Comunidad de Madrid, que puede considerarse como una herramienta de utilidad para los gestores y administradores encargados de la protección de este tipo de patrimonio
Hollow fiber membranes with different external corrugated surfaces for desalination by membrane distillation
No full textRegeneración de aguas tratadas mediante filtros verdes intensivos. La experiencia piloto en la depuradora de La Franca en Asturias
No full textThe potential for using red claw crayfish and hybrid African catfish as biological control agents for Schistosoma host snails
No full textThe potential of red claw crayfish and hybrid African catfish (Clarias gariepinus and Clarias ngamensis) as predators for Schistosoma host snails was evaluated in 2014 by monitoring the consumption of snails by crayfish and catfish in experimental tanks over time under laboratory conditions. After 15 days, both crayfish and catfish had significantly reduced the populations of Bulinus globosus. Crayfish consumed 6.9 snails d−1, whereas catfish consumed 5.9 snails d−1. However, when supplied with an alternative prey, Melanoides tuberculata (100 individuals per tank), crayfish clearly preferred M. tuberculata (100% consumed over seven days) to B. globosus (100 individuals per tank) (54% consumed over the same period). Catfish, conversely, did not have a clear preference for either prey species, consuming 77% and 88% of M. tuberculata and B. globosus, respectively. It was also observed that young catfish were more efficient predators than older ones, because of ontogenetic shifts in their diet with age. Hybrid catfish retain the molluscivorous characteristics of their parent stock and red claw crayfish also preys on Schistosoma host snails. However, the effectiveness of both predators is affected by the presence of an alternative prey. Therefore, under suitable conditions, these species can be considered for biological control of schistosomiasis transmission
