Hydrogenotrophic methanogenic activity test: theoretical basis, protocol design discussion and experiences for biosludge at different environmental conditions

Specific methanogenic activity is a cost-effective tool to characterize the biological activity of biosludge, to monitor reactor performance, and study the kinetics of acetate and H2 conversion to methane in anaerobic-digestion-based systems. More established protocols are applied for acetoclastic activity tests, while hydrogenotrophic activity tests are still less widespread and not standardized. Due to methodological differences, the few results found in the literature for hydrogenotrophic activity are difficult to compare. Drawbacks are observed when analyzing solids digesters, dealing with low activity values associated with biomass dilution by the substrate and inert, long measurement times, and significant microbial growth. Having a standardized technique is of utmost importance, and this thesis intends to contribute to this line. Full calculation and design conditions for hydrogenotrophic activity test are developed over this manuscript, based on kinetics for the H2/CO2 conversion to methane. An equation to calculate inoculum size is proposed, suitable for a wide variety of biosludge samples. Zero-order model fitted adequately for hydrogenotrophic activity determined in pilot-scale and full-scale reactor samples, with standard deviations for triplicates between 3 and 12%, based on headspace pressure measures. Kinetics for the four reactions involved in the last step of the anaerobic digestion process was considered to estimate methanogen fractions in microbial population and study pathway contributions during methanogenic activity tests. The inhibitor 2-Bromoethanesulfonate was dosed during methanogenic activity tests, obtaining a IC50 of 3 and 20 mM for acetoclastic and hydrogenotrophic methanogens, respectively, in granular sludge samples. Homoacetogens contributed about 6% of the hydrogenotrophic activity obtained without inhibitor; whereas, during the acetoclastic activity test, about 23% of methane was produced via syntrophic acetate oxidation, evidencing the importance of studying this route in anaerobic digestion systems. Finally, a case of solid waste digestion was analyzed, and a simple method was proposed to solve drawbacks during hydrogenotrophic test. The evolution of biomass, degradable, and non-degradable substrate was modeled for solids digestion during a batch incubation and then in a CSTR digester. Biomass correction factors were estimated and used as correctors of activity values to reflect microbial activity more accurately and improve the design of methanogenic activity tests.Los ensayos de actividad metanogénica constituyen una herramienta rentable para la caracterización biológica de lodos, el monitoreo de reactores y el estudio cinético de la conversión de acetato e hidrógeno a metano en sistemas de digestión anaerobia. Existen protocolos establecidos para el ensayo de actividad acetoclástica, mientras que el ensayo hidrogenotrófico está poco difundido y carece de protocolo estandarizado, lo que dificulta la comparación de los pocos resultados disponibles en bibliografía. Además, existen inconvenientes en su aplicación para lodos de digestores de sólidos, debido a la dilución de la biomasa por sustrato e inerte, causando actividades bajas y tiempos largos de prueba, con crecimiento microbiano significativo. Con esta tesis, se pretende contribuir a la estandarización de la técnica, abordando la base de cálculo y discutiendo las condiciones de diseño mediante modelos cinéticos simples. Se propone una ecuación para el cálculo del tamaño del inóculo a utilizar en la prueba. Se aplica un modelo de orden cero para obtener la actividad hidrogenotrófica a partir de la presión de cámara del vial, obteniéndose un buen ajuste y desviaciones estándares de 3 a 12% para muestras de reactores industriales y de banco. Se analiza asimismo la cinética de las cuatro reacciones involucradas en la metanogénesis, para estimar las fracciones de metanogénicos en la biomasa y estudiar la contribución de cada vía en los ensayos de actividad. Al aplicar el inhibidor 2-Bromoetanosulfonato de sodio, se obtienen IC50 de 3 y 20 mM para acetoclásticos e hidrogenotróficos en lodo granular, respectivamente. Se observa una contribución de la homoacetogénesis de 6% en la actividad hidrogenotrófica, mientras que se obtiene 23% de metano por la vía de oxidación sintrófica de acetato acoplada a la metanogénesis hidrogenotrófica durante el ensayo acetoclástico, evidenciando la importancia del estudio de esta ruta. Finalmente, se analiza un caso de digestores de sólidos, modelando la evolución de la biomasa y de las fracciones biodegradables y no biodegradables. Se determinan factores de dilución de biomasa, mostrando un método simple para mejorar el diseño de los ensayos metanogénicos y corregir los valores obtenidos para que reflejen mejor la actividad biológica de lodos de digestores de sólidos

Esclavo y reo: la doble condena de José Rufino Parra en las Antillas y en la España peninsular

This paper addresses the adversities of a slave in 19th century Cuba who was considered dangerous because of his education; the suspicious claim of the owner; the slave’s arrest between Cuba, Spain, and Puerto Rico, and the defence of the rights to which he was entitled. The scant but interesting documentation on the misfortune of José Rufino Parra raises many issues regarding the daily relationships between masters and slaves; the unheard-of relationship between a black man and a white woman; the conservation of family honour, and the importance of education and family for slaves within an unjust colonial system, which, despite injustices, did offer opportunities to defend themselves.El trabajo aborda la peripecia de un esclavo en la Cuba del siglo XIX considerado peligroso por su grado de instrucción, la sospechosa denuncia del propietario, su apresamiento entre Cuba, la península y Puerto Rico y la defensa de los derechos a que se hizo acreedor. La exigua pero interesante documentación sobre el infortunio de José Rufino Parra suscita muchos aspectos a tratar sobre las relaciones cotidianas entre amos y esclavos, lo insólito de la establecida en este caso entre un hombre negro y una mujer blanca, la salvaguarda del honor familiar, la importancia de la educación y la familia para el esclavo en un marco colonial injusto en el que, sin embargo, hubo algún resquicio para defenderse

Contribución al estudio de la nematofauna peri-radicular de la vid (Vitis vinifera L.) del Vallès Occidental (Barcelona)

This paper is a contribution to the knowledge of the free-living nematological fauna of Spanish vineyard soils and its seasonal fluctuations. Two Vitis vinifera fields were studied. One of them is under cultivation (V field) while the other was abandoned 10 years ago (CE field). Soils are alkaline, with sandy-loam (VI or sandyclay-loam (CE) textures. Ten soil samples were taken each season from each field, at a depth of 0-20 cm. Nematodes were extracted by the Baermann's method, stained with cotton blue and mounted in lactophenol. The following species are described: Labronema ferox, L. varicaudatum, L. maurit~ense, rapax, L. virgo, Discolaimus major, Mesodorylaimus bastiani, Xachtai- L.cum, X. italiae, Mononchus papillatus and a simple qualitative and quantitative study of these species in each season in both fields is made.El trabajo determina la nematofauna peri-radicular de la vid y la variación a que está sometida en las cuatro estaciones del año. Se han estudiado dos campos de fitis vinifera L., uno en cultivo (V) y el otro abandonado hace diez años (CE). Son suelos alcalinos de textura franco-arenosa en el campo V y franco-arcillo-arenosa en el CE. Se han cogido 10 muestras de suelo entre 0-20 cm, por campo y por estación. La extracción de nematodos se ha hecho por el metodo de Baermam. Los ejemplares se han teñido con cotton-blue y montado en lacto-fenol. Se describen las especies: Labronema ferox, L. varicaudatum, L. mauritiense, L. rapax, L. virgo, Disco-laimus major, Mesodorylaimus bastiani, X. pachtaicum, X. italiae y Mononchus papillatus, y se hace un pequeño estudio cualitativo y cuantitativo de esta nematofauna, en las diferentes estaciones en ambos campos

Conceptualising place branding in three approaches:towards a new definition of place brands as embodied experiences

Purpose: This paper aims to provide conceptual clarity on the different approaches of place branding in the literature. It discusses three main approaches and provides a new definition of place brands that acknowledges the full multi-sensory experience of place brands. This paper also elaborates brand management within the three approaches. Design/methodology/approach: Conceptual paper Findings: This study identifies three co-existing approaches of place branding and provides a definition of place brands for each of them. The first approach conceptualises place brands as symbolic constructs that identify and differentiate places from others. Brand symbols such as logos and slogans are central, assuming that brand meaning resides in them. The second approach views place brands as images and associations in the minds of target groups, whereby brands reside in individuals’ minds (the cognitive). This paper aligns with a third approach that views place brands as experiential, multi-sensory constructs. Brands invite not only mental representations in people’s minds but especially also multi-sensory embodied experiences. The authors thus define place brands as marketing systems that consist of dynamic performative assemblages of symbolic, discursive, institutional and material elements that selectively invite certain multi-sensory and embodied experiences of place by stakeholders and target groups. Originality/value: This paper contributes to conceptual clarity by providing an analytical framework identifying three main approaches to place branding. The authors further reflect on the implications of each approach for brand management. This paper also builds on recent literatures to provide a new and contemporary definition of place brands as multi-sensory experiences that encompasses embodiment.</p

Unravelling the link between actors’ roles in place branding processes and brand citizenship behaviour

Both scholars and practitioners agree that stakeholder participation in place branding processes is important for enhancing their support, often referred to as Brand Citizenship Behaviour (BCB). Stakeholder participation can be varied and is often linked to the different roles that place stakeholders can adopt in the place branding process. The literature suggests a link between different stakeholder roles taken along the branding process (from decision-making to implementation) and their voluntary and active supportive behaviours towards the brand project. Despite this recognition, many aspects related to place stakeholders’ roles and BCB remain underexplored, particularly what leads stakeholder to adopt certain roles and engage in behaviours associated with such roles. This study aims to fill this gap by using role theory as a theoretical lens to conceptually explore the different roles actors adopt in the place branding process, their motivations to adopting a certain role and the behavioural expectations that come with such roles. Given the complexity of places and interactive nature of place branding, we also reflect on the fluid and interrelated nature of such roles as they are constantly (re)shaped in the interactions between place stakeholders.</p