Feasibility and economic viability for decision making in the application of ashes in forest areas

La determinación de factibilidad, accesibilidad y logística para la aplicación de cenizas a áreas forestales, es una tarea compleja que agrupa varios objetivos. Este trabajo se centra en el uso de herramientas de Sistemas de Información Geográfica (SIG) en la toma de decisiones para la optimización de la aplicación de cenizas. El estudio se realizó en dos etapas. La primera consideró aspectos ambientales, sociales, culturales y económicos enmarcados en el artículo 12 del decreto 125/2012 de la Xunta de Galicia para determinar la factibilidad de aplicación de cenizas a áreas forestales. En la segunda se determinó la accesibilidad y logística de aplicación a montes forestales de la provincia de Lugo. Para ello se construyó un modelo heurístico e índice de rentabilidad económica por hectárea con ayuda de la herramienta network analyst de ArcGIS. Los resultados muestran que las herramientas de SIG, complementadas con trabajo en campo, facilitan la toma de decisiones y ayudan a redirigir la atención y recursos hacia aquellas superficies con un mayor potencial de aplicación de cenizasThe feasibility, accessibility and logistic determination for the ash application to forest areas, is a complex task the merge some objectives. This paper focus in the use of Geographic Information System (GIS) as a helper for decision-making of ash optimization application. The study was performed in two sections. The first section include environmental, social, cultural and economic aspects related to the article 12 of decree 125/2012 from the Xunta de Galicia for the feasibility determination of the ash application. The second one determinate the accessibility and logistic application to forestall places in Lugo province, so it was necessary to build a heuristic model and an economic rent index per hectare using the Network Analyst ArcGIS tool. The results shows that the GIS, complement it with fieldwork, tools helps the decision-making and to redirect the resources attention to those areas with better potential of ash applicationS

Configuraciones de control de las redes de poder empresarial en España

The research studies control corporate structures and distribution in those networks formed by the shareholders and the managerial boards of directors (CA) of the 227 largest Spanish companies in terms of operating income (IE) in 2013. The results allows to identify three control patterns. First, a dense network of shareholders and managers that develop a centralized core and exercise direct control. Secondly, a set of Global Collective Investment Institutions (IICs), mostly non-residents, exercising a style of indirect control through the participation in the capital of Spanish companies or through subsidiaries of transnational corporations, which play through the elaboration and negotiation strategies from outside the managerial boards of the investees. Third, a more personal and direct control pattern exercised by blockholders and managers in isolated companies.El presente trabajo estudia las estructuras y la distribución del control corporativo en las redes formadas por los accionistas y consejeros de administración (CA) de las 227 mayores empresas españolas en términos de ingresos de explotación (IE) del año 2013. El análisis de los resultados permite identificar tres pautas de control. Primero, una densa red de accionistas y administradores que forman un núcleo centralizado y que ejercen un control directo. Segundo, un conjunto de Instituciones de Inversión Colectiva globales (IIC), mayoritariamente no residentes, que ejercen un estilo de control indirecto mediante la participación en el capital de empresas españolas o a través de filiales de empresas transnacionales, y que intervienen mediante la elaboración y negociación de estrategias desde fuera de los órganos de gestión de las empresas participadas. Tercero, una pauta de control más personal y directo ejercido por blockholders y administradores en empresas aisladas

Methanogens, sulphate and heavy metals: a complex system

Anaerobic digestion (AD) is a well-established technology used for the treatment of wastes and wastewaters with high organic content. During AD organic matter is converted stepwise to methane-containing biogasa renewable energy carrier. Methane production occurs in the last AD step and relies on methanogens, which are rather sensitive to some contaminants commonly found in wastewaters (e.g. heavy metals), or easily outcompeted by other groups of microorganisms (e.g. sulphate reducing bacteria, SRB). This review gives an overview of previous research and pilot-scale studies that shed some light on the effects of sulphate and heavy metals on methanogenesis. Despite the numerous studies on this subject, comparison is not always possible due to differences in the experimental conditions used and parameters explained. An overview of the possible benefits of methanogens and SRB co-habitation is also covered. Small amounts of sulphide produced by SRB can precipitate with metals, neutralising the negative effects of sulphide accumulation and free heavy metals on methanogenesis. Knowledge on how to untangle and balance sulphate reduction and methanogenesis is crucial to take advantage of the potential for the utilisation of biogenic sulphide as a metal detoxification agent with minimal loss in methane production in anaerobic digesters.The research was financially supported by the People Program (Marie Curie Actions) of the European Union's Seventh Framework Programme FP7/2007-2013 under REA agreement 289193

Veterinary antibiotic removal in a two step nitrification process treating manure digestate

Short-cut biological nitrogen removal is considered a reliable and cost effective technology to treat effluent from anaerobic digestion compared to conventional activated sludge treatment; however there is a lack of knowledge concerning removal of antibiotics in via-nitrite systems. The aim of this study was to clarify the role of nitrifier populations in the removal of veterinary antibiotics compounds. Fate and removal of two antibiotics, oxitetracycline and chlorotetracycline, were assessed in two-sludge activated sludge systems treating manure digestate and enriched with nitrifiers. Partial nitritation of influent nitrogen was accomplished in the first stage, while the second reactor completed the nitrification to nitrate. Results showed that higher degree of tetracycline degradation was observed in enriched nitrifying system compared to a conventional activated sludge. CTC disappeared at a higher extent but its removal was affected by its low stability under the temperature of operation. On the contrary, OTC was more stable and its removal was influenced by the variation in the activity of the nitrite oxidizing bacteria