Seeking to enhance the bioenergy of municipal sludge: Effect of alkali pre-treatment and soluble organic matter supplementation

The aim of this research is to enhance the mesophilic anaerobic digestion of municipal sludge from Cadiz-San Fernando (Spain) wastewater treatment plant at 20 days hydraulic retention time (HRT). Two different strategies were tested to improve the process: co-digestion with the addition of soluble organic matter (1% v/v); and alkali sludge pre-treatment (NaOH) prior to co-digestion with glycerine (1% v/v). Methane production (MP) was substantially enhanced (from 0.36 ± 0.09 L CH4 l/d to 0.85 ± 0.16 L CH4 l/d), as was specific methane production (SMP) (from 0.20 ± 0.05 L CH4/g VS to 0.49 ± 0.09 L CH4/g VS) when glycerine was added. The addition of glycerine does not seem to affect sludge stability, the quality of the effluent in terms of pH and organic matter content, i.e. volatile fatty acids (VFA), soluble organic matter and total volatile solid, or process stability (VFA/Alkalinity ratio < 0.4). Alkali pre-treatment prior to co-digestion resulted in a high increase in soluble organic loading rates (more than 20%) and acidification yield (more than 50%). At 20 days HRT, however, it led to overload of the system and total destabilization of the mesophilic anaerobic co-digestion of sewage sludge and glycerine

Mesophilic anaerobic co-digestion of sewage sludge with glycerine: Effect of solids retention time

The main objective of this paper is to examine the effect of the increase in organic loading rates (OLRs), by reducing the solids retention time (SRT) from 20 d to 5 d, in single-phase mesophilic anaerobic co-digestion of sewage sludge with glycerine (1% v/v). It was experimentally confirmed that anaerobic co-digestion of these biowastes under steady-state conditions can achieve an 85 ± 5% reduction in volatile fatty acids (VFA) at SRTs of between 20 and 9 d, with a methane production yield of around 0.8 l CH4/l/d. Decreases in the SRT not only allow the sludge stability and biogas production to be maintained, but also lead to an increase in the waste that could be treated and lower operating costs. Therefore, mesophilic anaerobic co-digestion of sewage sludge and glycerin at a SRT lower than 20 d is possible and preferable due to being more economical and environmentally friendl

El fenómeno del botellón desde una óptica jurídica

Se hace referencia a la legislación autonómica relativa al fenómeno del botellón , en la que se prohíbe el consumo de alcohol en la vía pública, y se cita alguna de la jurisprudencia derivada de dicha problemática. También se analiza uno de los aspectos más controvertidos en los temas relacionados con el consumo de alcohol en la vía pública: el relativo a la potestad normativa de las entidades locales, que parece pueden dictar normativa al respecto, pero en sentido restrictivo, respetando la normativa emanada de la legislación autonómica

Synaptic connections of calretinin-immunoreactive neurons in the human neocortex

Previous immunocytochemical studies in the cerebral cortex of various species have shown that the calcium-binding protein calretinin (CR) labels specific subpopulations of nonspiny non-pyramidal cells (interneurons). The present study attempts to characterize morphologically and chemically the microcircuitry of CR-immunoreactive (CR-ir) neurons in the human temporal neocortex. Postembedding immunocytochemistry for CR and GABA and combination immunocytochemistry for OR and non-phosphorylated neurofilament protein (NPNFP) or for CR and the calcium-binding proteins parvalbumin (PV) and calbindin (CB) showed CR multiterminal endings frequently innervating the distal apical dendrite or the cell body and proximal dendrites of NPNFP-ir or CB-ir pyramidal cells, respectively. Cell bodies of interneurons immunoreactive for CB or PV were innervated only occasionally by CR multiterminal endings, whereas certain GABA neurons were surrounded by them. Furthermore, CR-ir axon terminals formed either symmetrical (the majority) or asymmetrical synapses with a variety of postsynaptic elements. These results indicate that different subpopulations of CR interneurons exist that are specialized for selective innervation of somatic or dendritic regions of certain pyramidal and nonpyramidal neurons.Peer Reviewe

Membranas sintéticas impermeables y capas auxiliares separadoras en la cubierta plana invertida. Efecto de la presión sobre la degradación

Flat roofs are inverted when the insulation material is placed over the waterproofing membrane. This widely-used constructive system sets materials which may interact easily with each other causing their deterioration. The incompatibilities and the materials that may interact with each other are not completely described, the elements currently used to separate the materials are not totally efficient to avoid deterioration. This paper intends to enlarge the knowledge regarding the materials that are incompatible for inverted flat roofs, the conditions were interactions take place and the efficiency of some alternative solutions to separate the materials. The ethylene propylene diene monomer (EPDM) waterproofing membranes are incompatible with the extruded polystyrene (XPS). The interactions between incompatible materials increase with the pressure.Las cubiertas planas son invertidas cuando el material aislante se coloca sobre la membrana impermeable. Este sistema constructivo ampliamente utilizado emplea materiales que pueden interactuar con facilidad entre ellos, produciendo deterioro. Las incompatibilidades y los materiales que pueden interactuar no se han descrito completamente, los elementos utilizados actualmente para separar los materiales no son totalmente eficientes para evitar el deterioro. Este artículo pretende aumentar el conocimiento acerca de que materiales son incompatibles en la cubierta invertida plana, las condiciones para que las interacciones se den, y la eficiencia de algunas alternativas para separar materiales. Las membranas impermeables de etileno propileno monómero dieno (EPDM) son incompatibles con el poliestireno extrusionado (XPS). Las interacciones entre materiales incompatibles aumentan con la presión

Estudio comparativo con microscopio electrónico de barrido de la degradación de una lámina impermeable de cloruro de polivinilo plastificado en diferentes condiciones

This paper discusses the analysis of several samples of a plasticized polyvinyl chloride (PVC-P) waterproofing membrane. The samples were extracted from different areas of the same flat roof, which was in service for over 12 years. An original sample of an identical PVC-P membrane that was not installed on the roof was also analyzed. The analysis of the materials was carried out using a scanning electron microscope (SEM). An elemental analysis of every sample was also performed by energy dispersive X-ray spectroscopy (EDS). Micrographs and the elemental composition of the samples were compared with the data obtained in the analysis of the original sample. The results show dehydrochlorination of the polymer in two of the samples studied and great deterioration that was not visible to the naked eye in the sample that was totally exposed to the weather.Este estudio discute el análisis de varias muestras de una membrana impermeable de cloruro de polivinilo plastificado (PVC-P). Las muestras fueron extraídas de diferentes áreas de la misma cubierta plana, que estuvo en servicio durante más de 12 años. Una muestra original de idéntica membrana de PVC-P que no estuvo instalada en la cubierta fue también analizada. El análisis de los materiales se llevó a cabo utilizando un microscopio electrónico de barrido (MEB). Además se realizó un análisis elemental sobre cada una de las muestras mediante espectroscopía de dispersión de energía de rayos X (EDS). Las micrografías, y la composición elemental de las muestras, se comparan con los datos obtenidos en el análisis de la muestra original. Los resultados muestran deshidrocloración del polímero en dos de las muestras estudiadas, y un gran deterioro de la muestra totalmente expuesta a la intemperie, que no era visible a simple vista

METHODOLOGICAL APPROACH TO INTEGRATE A GIS-BASED ANALYSIS INTO THE DESIGN OF CULTURAL ITINERARIES IN THE FRAMEWORK OF AN INTEGRATED PLAN FOR TERRITORY

Abstract. The historical concept of heritage, which mostly comprised physical architectural and archaeological evidences, has been extended to the surrounding landscape in the last decades. This tendency has been corroborated by a series of International Charters and the European Landscape Convention of 2000. Landscape, understood as the perceptible part of territory that supports the contingencies throughout history, is subject to protection, management and planning. However, some inherent aspects of territory have been disregarded because of the frantic enlargement of cities throughout the twentieth century at the expense of the rural areas. Territorial heritage, which is fundamental to cultural landscape formation, is currently considered a strategic resource able to guarantee self-sustaining development of peri-urban and rural zones. In many cases, urban investments and planning associated to the enlargement of the metropolitan areas have overlooked this fruitful territorial heritage, making cultural landscapes illegible. This is the case of the cultural landscapes in the buffer zones of the archaeological sites, which are part of a diffuse territorial heritage that requires to be assessed by means of some innovative approaches. Cultural itineraries are presented as a landscape architecture strategy for valorising territorial heritage. Well-targeted design of these itineraries can also contribute to restore the dynamics of cultural landscape formation and to regenerate peri-urban and rural areas by promoting its self-sustaining development. To that end, the conceptualisation and hypotheses posed by some authors of the Società dei Territorialisti/e are used as references. A work methodology to design cultural itineraries is suggested in line with the presumptions of an integrated plan for territory aimed to valorise the territorial heritage. This paper explores in which way a GIS-based analysis can be integrated into the design of a landscape architecture like the cultural itinerary