93 research outputs found
Situación profesional de los recursos humanos de la actividad fÃsica y el deporte en el municipio de Coslada
El objetivo principal del estudio es conocer, la situación profesional de las personas que trabajan en funciones de actividad fÃsica y deporte en organizaciones subcontratadas en el municipio de Coslada. En él, se describen la situación socio-demográfica, laboral y formativa asà como, las diferentes funciones laborales desarrolladas por las personas objeto de estudio. La metodologÃa utilizada es descriptiva, en la que se realiza entrevista estandarizada por medio de cuestionario a 112 personas que trabajan en el municipio. Los resultados más representativos determinan que las funciones son variadas y diversificadas y que existe una contratación principalmente temporal, estableciéndose un elevado porcentaje de personas no tituladas realizando funciones para las que no están cualificada
Removal of mercury bonded in residual glass from spent fluorescent lamps
The current technologies available for recycling fluorescent lamps do not completely remove the phosphor powder attached to the surface of the glass. Consequently, the glass contains the mercury diffused through the glass matrix and the mercury deposited in the phosphor powder that has not been removed during treatment at the recycling plant. A low-cost process, with just one stage, which can be used to remove the layer of phosphor powder attached to the surface of the glass and its mercury was studied. Several stirring tests were performed with different extraction mixtures, different liquid–solid ratios, and different agitation times. The value of the initial mercury concentration of the residual glass was 2.37 ± 0.50 μg/g. The maximum extraction percentage was 68.38%, obtained by stirring for 24 h with a liquid–solid ratio of 10 and using an extraction solution with 5% of an acid mixture prepared with HCl and HNO3 at a ratio of 3:1 by volume. On an industrial scale the contact time could be reduced to 8 h without significantly lowering the percentage of mercury extracted. In fact, 64% of the mercury was extracted
Determination of mercury distribution inside spent compact fluorescent lamps by atomic absorption spectrometry
In this study, spent compact fluorescent lamps were characterized to determine the distribution of mercury. The procedure used in this research allowed mercury to be extracted in the vapor phase, from the phosphor powder, and the glass matrix. Mercury concentration in the three phases was determined by the method known as cold vapor atomic absorption spectrometry. Median values obtained in the study showed that a compact fluorescent lamp contained 24.52 ± 0.4 ppb of mercury in the vapor phase, 204.16 ± 8.9 ppb of mercury in the phosphor powder, and 18.74 ± 0.5 ppb of mercury in the glass matrix. There are differences in mercury concentration between the lamps since the year of manufacture or the hours of operation affect both mercury content and its distribution. The 85.76% of the mercury introduced into a compact fluorescent lamp becomes a component of the phosphor powder, while more than 13.66% is diffused through the glass matrix. By washing and eliminating all phosphor powder attached to the glass surface it is possible to classified the glass as a non-hazardous waste
A methodology for assessing the potential environmental impact of failure of leachate-retaining earthen dams
We describe herein a useful model for assessing the environmental impact of the breakage of earthen dams used to retain leachate fluids. To create this model, we analyzed three parameters: (1) the characteristics of both the earthen dam and the leachate; (2) the behavior of the leachate cascade resulting from breakage of the dam; and (3) the environmental effect of the resulting pollution. To accomplish this, we first analyzed the failure of earthen dams for leachate according to the Dam Break Inundation Analysis methodology, which provides the characteristics of the leachate cascade or avalanche resulting from the dam breakage. We then used data for different earthen dams for leachates and calculated the volume of leachate that would reach each point the leachate-flow bed downstream of the dam to generate a graph identifying areas at risk from the leachate cascade. As a third step, we calculated the pollutant charge of leachate, and lastly identified and assessed the environmental factors (EFs) within the risk area. Through these steps we formulated an equation for the environmental risk index (ERI EF), which quantifies the potential environmental impact of the rupture of an earthen dam for leachate on the area surrounding such a dam, and which has a value that ranges from 0 to 1. In order to validate this methodology, we applied the ERI EF equation to nine man-made earthen dams for leachates.
All nine are considered safe facilities in having had no accidents in the years since their construction. All have ERI EF values below 0.12, indicating that this value can serve as an appropriate guide to the environmental impact of the rupture of earthen dams that retain leachate
El combustible sólido recuperado: Producción y marco regulador
En los diferentes modelos de plantas de tratamiento de residuos domiciliarios, además de recuperar materiales destinados al reciclaje, se generan unos rechazos que no tiene utilidad y que generalmente se destina a vertedero. Sin embargo, poseen un contenido energético elevado debido a que están formados por una mezcla de materiales combustibles. La principal alternativa para la valorización de los rechazos es su conversión en un combustible sólido recuperado (CSR), con ello se lograrÃa reducir el volumen de residuos enviados a vertedero y proporcionar combustibles alternativos para las industrias que hacen un uso intensivo de energÃa no renovable. En este artÃculo se presenta el marco normativo y legal de los CSR en España y se compara con el de otros paÃses europeos. En este sentido, se analizarán los parámetros de calidad exigidos hoy en dÃa a nivel europeo. Además, también se analizan los posibles usos del CSR y su posibilidad de considerarlos como un subproducto en lugar de residuoIn the different models of domestic waste treatment plants two materials are
recovered: materials to be recycled, and useless materials that are transferred to
dumping sites. However, the latter possess high energetic levels since they are
formed by a mixture of combustible materials. The main alternative regarding
those products is their conversion to refuse-derived fuel (RDF), since the volume
of waste sent to dumping sites would decrease and alternative fuels would be
provided to factories making intensive use of non-renewable energies. This paper
presents the legal and normative framework concerning RDF in Spain, comparing
it to other European countries. The quality parameters demanded in the European
context are analysed, together with the possible uses of RDF and the possibility to
consider RDF a sub-product rather than waste
Analysis of the waste selective collection at drop-off systems: Case study including the income level and the seasonal variation
There are several factors which have an influence in the selective collection of the municipal waste. To define a selective collection system, the waste generation pattern should be firstly determined and these factors should be analyzed in depth. This paper tries to analyze the economic income level and the seasonal variation on the collection and the purity of light-packaging waste to determine actions to improve the waste management plan of a town. In the first stage of the work, waste samples of the light-packaging containers were collected in two zones of the town with different economic characteristics in different seasons during one year. In the second stage, the samples were characterized to analyze the composition and purity of the waste. They were firstly separated into four fractions: metals; plastic; beverage cartons; and misplaced materials. The misplaced fraction was in its turn separated into cardboard, rubber and leather, inert waste, organic matter, paper, hazardous waste, clothes and shoes, glass and others. The plastic fraction was separated into five types of plastics and the metal fraction into three. In the third stage, the data have been analyzed and conclusions have been extracted. The main result is that the quality of the light-packaging fraction collected in these zones during both seasons were similar. This methodology can be extrapolated to towns with similar characteristics. It will be useful when implementing a system to collect the waste selectively and to develop actions to achieve a good participation in the selective collection of the waste
Factors determining waste generation in Spanish towns and cities
This paper analyzes the generation and composition
of municipal solid waste in Spanish towns and
cities with more than 5000 inhabitants, which altogether
account for 87 % of the Spanish population. To do so,
the total composition and generation of municipal solid
waste fractions were obtained from 135 towns and cities.
Homogeneity tests revealed heterogeneity in the
proportions of municipal solid waste fractions from
one city to another. Statistical analyses identified significant
differences in the generation of glass in cities of
different sizes and in the generation of all fractions
depending on the hydrographic area. Finally, linear regression
models and residuals analysis were applied to
analyze the effect of different demographic, geographic,
and socioeconomic variables on the generation of waste
fractions. The conclusions show that more densely populated
towns, a hydrographic area, and cities with over
50,000 inhabitants have higher waste generation rates,
while certain socioeconomic variables (people/car) decrease
that generation. Other socioeconomic variables
(foreigners and unemployment) show a positive and null
influence on that waste generation, respectively
Application of inert wastes in the construction, operation and closure of landfills: calculation tool
Waste from construction and demolition activities represents one of the highest volumes of waste in Europe. 500 million tonnes are produced throughout the whole EU every year. In some EU members like Spain, approximately 83 per cent of such waste is disposed in landfills. The remaining part is classified and processed in treatment facilities so that it can later be used as recycled aggregates in the construction sector (sand, gravel, aggregates, etc.) but without much commercial success. The aim of this study is to use recycled aggregates from inert wastes (IW) in the different phases of a landfill (construction, operation and closure) with the aid of a new computer tool called LABWASTE.14. This tool incorporates the mathematical relationship among the activities of the landfill and provides as a result the economic viability of using recycled aggregates compared to aggregates from quarries. Therefore, knowing the needs of aggregates in landfills (dams, drainage layers, covering layers, collection wells, etc.) may determine the amount of IW that could be recovered. These calculations can be obtained from some of the data that is introduced (population, land physiography, etc.). Furthermore, the use of LABWASTE.14 makes it possible to reduce the demand for aggregates from quarries
Análisis de la evolución de las plantas de tratamiento mecánico-biólogico de residuos en España
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