Anaerobic Biodegradation of Solid Substrates from Agroindustrial Activities — Slaughterhouse Wastes and Agrowastes

Solid wastes from the meat industry are produced in large amounts resulting in a negative impact on the environment if not properly treated. Due to their high content of proteins and fats, these residues are excellent substrates for anaerobic digestion which holds high potential for methane yield. However, possible toxic compounds may be formed during its biodegradation with a consequent failure of the process under long-term operation. The anaerobic co-digestion of such residues with other co-substrates as those generated in agricultural activities has been proposed as a good alternative to overcome these problems. Nevertheless, today there is very little knowledge to assess on mixture interactions connected to wastes composition, biodegradability, and the kinetics of the anaerobic process when complex materials are utilized in ternary and quaternary mixture, specifically when co-digesting solid cattle slaughterhouse waste with agrowaste. It is therefore important to select the right combination of substrates and ratios to obtain synergy instead of antagonism in those mixtures. This chapter aims to provide an overview of the anaerobic digestion of solid slaughterhouse waste and agrowaste, as well as the influence of mixture interactions on its biodegradation

Inventario de emisiones derivadas de fermentación entérica y gestión del estiércol del Parque Zoológico Nacional

Zoos are spaces focused on the preservation of world flora and fauna, however, directly or indirectly, they develop activities that bring polluting effects to the environment. Within this context, Greenhouse Gas emissions generated by enteric fermentation of cattle and those derived from manure management have received special attention as part of inventories, due to the impact they cause on climate change. The objective of this work is oriented to count the emissions of these categories established by the Intergovernmental Panel on Climate Change for the realization of inventories, taking the National Zoological Park as a case study. This recreational scientific center houses the vast majority of wild animals, for which there are no emission factors for enteric fermentation. In this inventory, zoo animals belonging to 5 taxonomic families, located in the different areas of the zoo, as well as in the Agricultural Development Unit, were included, and for them approximate factors were calculated based on those proposed in these methodologies. Regarding the management of manure or composting, related to the use of cattle feces as soil fertilizers, solid humus from specimens of the Bovine and Buffalo breeds was used. The methodology applied in this research can be extended to the rest of the country's zoos, contributing to the sustainability of these spaces.Los zoológicos constituyen espacios enfocados a la preservación de la flora y fauna mundial, sin embargo, de forma directa oindirecta, desarrollan actividades que traen consigo efectos contaminantes al medio ambiente. Dentro de este contexto, las emisiones de Gases de Efecto Invernadero generadas por la fermentación entérica del ganado y las derivadas de la gestión del estiércol, han recibido una atención especial como parte de los inventarios, por el impacto que ocasionan sobre el cambio climático. El objetivo del presente trabajo está orientado a contabilizar las emisiones de estas categorías establecidas por el Panel Intergubernamental sobre Cambio Climático para la realización de inventarios, tomándose como caso de estudio el Parque Zoológico Nacional. Este centro científico recreativo alberga en la gran mayoría, animales silvestres, para los que no se cuenta con factores de emisión por fermentación entérica. En este inventario se incluyeron animales del zoológico que pertenecen a 5 familias taxonómicas, ubicados en las distintas áreas del mismo, así como en la Unidad de Desarrollo Agrícola y para ellos se calcularon factores aproximados en base a los propuestos en estas metodologías. Con respecto a la gestión del estiércol o compostaje, relacionada con el empleo de las heces de ganado como fertilizantes de suelos, se hizo uso del humus sólido proveniente de ejemplares de las razas Bovinos y Bufalinos. La metodología aplicada en esta investigación puede ser extendida al resto de los zoológicos del país, contribuyendo a la sostenibilidad de estos espacios

Análisis del inventario de gases de efecto invernadero emitidos en la producción de vidrio en Cuba

The development of man and the industrialization of society bring with them the generation of a large number of substances that modify the natural composition of the air. Among these pollutants are greenhouse gases whose accumulation causes harmful effects on the planet such as climate change. This research was carried out with the objective of carrying out a pollutants are greenhouse gases inventory, expressed in terms of equivalent CO2, emitted in the glass production process corresponding to the period 2015-2019. The activity data provided by the entity were collected and analyzed and the GHG sources that represent the main emissions were identified, using the methodology of Intergovernmental Panel on Climate Change. A technical-economic proposal for mitigation was made of these gases. Stationary sources are the variable that has the greatest influence on CO2 emissions, in the 2015-2019 period, when compared with emissions related to the decarbonation of raw materials and electricity consumption. The consumption of fuel oil has a statistically significant influence on CO2 emissions, associated with stationary sources, unlike the consumption of used oils and natural gas. The substitution of diesel for fuel oil, manages to reduce emissions by 464, 48 t CO2 for the year 2015.El desarrollo del hombre y la industrialización de la sociedad traen consigo la generación de una gran cantidad de sustancias que modifican la composición natural del aire. Entre estos contaminantes se encuentran los gases de efecto invernadero cuya acumulación provoca efectos perjudiciales al planeta como el cambio climático. Esta investigación se realizó con el objetivo de realizar un inventario de gases de efecto invernadero, expresados en términos de CO2 equivalentes, emitidos en el proceso de producción de vidrio correspondiente al período 2015-2019. Se recolectaron y analizaron los datos de actividad ofrecidos por la entidad y se identificó las fuentes de gases de efecto invernadero que representan las principales emisiones, empleando la metodología delPanel Intergubernamental de Cambio Climático. Se realizó una propuesta técnico-económica para la mitigación de estos gases. Las fuentes estacionarias es la variable que tiene una mayor influencia en las emisiones de CO2, en el período del 2015-2019, al compararla con las emisiones referidas a la descarbonatación de las materias primas y con el consumo de electricidad. El consumo de fuel oil influye de forma estadísticamente significativa en las emisiones de CO2, asociadas a las fuentes estacionarias, a diferencia del consumo de aceites usados y gas natural. La sustitución del fuel oil por diésel, logra disminuir las emisiones en 464,48 tCO2 para el año 2015

Analysis of labour market needs for engineers with enhanced knowledge in renewable energy in some European and Latin-American Countries

One of the main challenges related to the renewable energy labour market is that of human capital and as a consequence the educational profile of future employees is of paramount importance. Unfortunately, the skill level gained at University does not always fit with the practical needs of industry thus reducing the benefit-cost ratio of new employees and slowing down the transition to a green economy. Within this context, ‘The Crux’ project co-funded by EU under the framework of the Erasmus + programme aims at improving the renewable energy engineering curriculum at different university levels in several Universities of Latin America and Europe. In order to better appreciate the potential impact of the project, a survey on the labour market need for specialists with enhanced knowledge and skills in renewable and sustainable energy technologies has been conducted in the related EU and Latin America countries. More precisely, 60 organizations have been interviewed and almost 70% of them are interested in employing engineers with enhanced knowledge on renewable energy in the next three years. The analysis has shown significant discrepancies between EU and Latin American organizations. In fact, while future employees in EU countries will be mainly related to solar energy and management, the former together with wind and biomass will represent the main renewable energy working sector in Latin American countries. Moreover, MSc level will be the most demanded in EU while bachelor education seems to satisfy the future industry requirements in Latin America. Despite each country having its own needs, the research carried out under this EU project confirms the potential of renewable energy education on the global labour market in the near future

Anaerobic co-digestion of solid slaughterhouse wastes with agro-residues : Synergistic and antagonistic interactions determined in batch digestion assays

Different mixture ratios of solid cattle slaughterhouse wastes (SB), manure (M), various crops (VC), and municipal solid wastes (MSW) were investigated for biogas production. The objective was to explore possible significant synergistic effects obtained from the combination of these different substrates. The performance of the process was assessed in thermophilic anaerobic batch co-digestion assays, using a four factor mixture design and methane yield (Y-CH4) and specific methane production rate (r(scH4)) as response variables. The highest methane yield, 655 NmL CH4/g VS was obtained when equal parts (ww) of SB, M, VC, and MSW were combined, while the combination of SB, M, and MSW resulted in the highest specific methane production rate (43 NmL CH4/g VS/d). A mixture design model was fitted to data in order to appraise synergistic and antagonistic interactions. Mixing all four substrates resulted in a 31% increase of the expected yield which was calculated from the methane potential of the individual fractions, clearly demonstrating a synergistic effect due to more balanced nutrient composition enhancing the anaerobic digestion process. However, no significant antagonistic effects were observed. In order to maximize both response variables simultaneously, a response surface method was employed to establish the optimal combination of substrate mixtures. The statistical results and analysis of the biological process gave a coherent picture of the results. (C) 2014 Elsevier B.V. All rights reserved