The performance of horizontal subsurface flow constructed wetlands in the removal of micropollutants from a wastewater treatment plant effluent was evaluated at mesocosm level. Fifteen mesocosms were studied following a modified Latin Square experimental design with six additional points. Three variables at three levels were studied: porous media -PM- (river gravel, fine volcanic gravel and coarse volcanic gravel), macrophyte type -M- (Thypa latiffolia, Phragmites australis, and Cyperus papyrus) and hydraulic retention time -HRT- (1, 3 and 5 days). As response variables the removal percentages of the total organic load of the effluent (BOD5) and the loads of several micropollutants (caffeine, galaxolide, tonalide, alkylphenols and their monoethoxylates and diethoxylates, methyl dihydrojasmonate, sunscreen UV-15 and parsol) were used. The results showed that the systems remove between 70% and 75% of the organic load and that all the micropollutants were degraded at different extents, from 55% to 99%. The HRT was the variable that showed major effects on the treatment process, while M and PM showed no statistically significant differences in the used experimental conditions.
Con la finalidad de rescatar los aspectos históricos del cooperativismo en la mixteca poblana, se realizó una investigación cualitativa mediante un instrumento de entrevista semiestructurada que se aplicó a los familiares de los ejidatarios fundadores de una granja porcina constituida como cooperativa en la comunidad de Santa Cruz Agua Escondida. Las preguntas fueron estructuradas en ocho rubros: integración de la organización, política organizacional, actividades realizadas, control de calidad, sistemas de financiamiento, identidad organizacional, procesos de formación y declive de la organización. Los resultados muestran que el establecimiento de la granja se dio a través de un crédito del Banco del Crédito Rural del Centro Sur, la granja representó una importante fuente de empleo, con el cierre de las actividades hubo un incremento en diversos problemas sociales como inseguridad y drogadicción, la cooperativa contaba con asesoría técnica esporádica, pero no en temas de índole financiero y el declive de la granja se dio cuando la mayoría de los miembros salieron de la cooperativa pues de 45 ejidatarios fundadores solo terminaron 13 lo que derivó en complicaciones económicas y en el cierre definitivo. Se concluye que, a pesar de los múltiples esfuerzos por parte de las autoridades federales de impulsar el desarrollo del campo, la falta de asistencia técnica y financiera ha imposibilitado la continuidad de proyectos como el que se aborda en este trabajo.
The energy crisis, water scarcity and poor air quality are issues that must be addressed urgently in order to ensure the well-being of the population. The use of alternative technologies such as constructed wetlands (CW) allow the treatment of different wastewaters. When these technologies are coupled to bioelectrochemical systems (BES), the removal of the organic load can be optimized and electrical energy can be generated. Thus, the aim of this work was to perform an analysis of the advances, from 2010 to 2017, on the design of various configurations of CW systems coupled to BES. It was possible to identify the most important variables that determine the efficiency of removal of pollutants and current generation such as anodic and cathodic materials, area of electrodes, type of macrophytes and material organic removed. Likewise, the values of the organic material removed and the maximum power densities obtained with the three most used macrophytes are presented.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.