An archaeology of colonialism, conflict, and exclusion : conflict landscapes of Western Sahara : in two volumes: volume one

When Spain gave up its colony of Spanish (now Western) Sahara in 1975, it was annexed by Morocco and Mauritania. A sixteen-year war ensued, leaving the country divided between Morocco and the Polisario Front. This unresolved conflict left indelible scars on the landscape, mainly battlescapes, made up of numerous field fortifications littered with the detritus of war, and ‘the berm’ (or ‘berms’) a succession of fortified earth and stone walls constructed by Morocco between 1980 and 1987, partitioning a formerly pastoral landscape, and excluding pro-independence Saharawis from the western four-fifths of their country. This dissertation will explore how this desert landscape has been transformed by colonialism and war, and how in some ways, the Saharawi people are actively reappropriating their land. This will be done by looking at the landscape at three levels of resolution. The broadest, or national level, will chart the growth and spread of the berms, illustrating the material extent of Moroccan colonial control, and the exclusion of Saharawis within and outside the territory. The middle, or regional level, will explore the militarisation of one settlement – Tifariti – which was fought over during the war, and which hosted a unique art festival between 2007 and 2010. The third, finer level, will look at the land art that was created as a result of the art festival, and which is now a new stratum of contemporary archaeology, overlying the extensive prehistoric archaeology evident in the region. A great number of national barriers are at this moment being raised around the globe, with countries adopting siege mentalities with their neighbours. This dissertation will explore how archaeology can apply a multi-disciplinary approach, drawing upon a variety of resources, to help us understand the contemporary phenomena of conflict and exclusion, through the unique example of Western Sahara

Life cycle assessment of constructed wetland systems for wastewater treatment coupled with microbial fuel cells

The aim of this study was to assess the environmental impact of microbial fuel cells (MFCs) implemented in constructed wetlands (CWs). To this aim a life cycle assessment (LCA) was carried out comparing three scenarios: 1) a conventional CW system (without MFC implementation); 2) a CW system coupled with a gravel-based anode MFC, and 3) a CW system coupled with a graphite-based anode MFC. All systems served a population equivalent of 1500 p.e. They were designed to meet the same effluent quality. Since MFCs implemented in CWs improve treatment efficiency, the CWs coupled with MFCs had lower specific area requirement compared to the conventional CW system. The functional unit was 1 m3 of wastewater. The LCA was performed with the software SimaPro® 8, using the CML-IA baseline method. The three scenarios considered showed similar environmental performance in all the categories considered, with the exception of Abiotic Depletion Potential. In this impact category, the potential environmental impact of the CW system coupled with a gravel-based anode MFC was around 2 times higher than that generated by the conventional CW system and the CW system coupled with a graphite-based anode MFC. It was attributed to the large amount of less environmentally friendly materials (e.g. metals, graphite) for MFCs implementation, especially in the case of gravel-based anode MFCs. Therefore, the CW system coupled with graphite-based anode MFC appeared as the most environmentally friendly solution which can replace conventional CWs reducing system footprint by up to 20%. An economic assessment showed that this system was around 1.5 times more expensive than the conventional CW system.Peer ReviewedPostprint (author's final draft

Life cycle assessment of drinking water: comparing conventional water treatment, reverse osmosis and mineral water in glass and plastic bottles

This study evaluated the environmental impacts caused by drinking water consumption in Barcelona (Spain) using the Life Cycle Assessment (LCA) methodology. Five different scenarios were compared: 1) tap water from conventional drinking water treatment; 2) tap water from conventional drinking water treatment with reverse osmosis at the water treatment plant; 3) tap water from conventional drinking water treatment with domestic reverse osmosis; 4) mineral water in plastic bottles, and 5) mineral water in glass bottles. The functional unit was 1 m3 of water. The water treatment plant considered in scenarios 1, 2 and 3, treats around 5 m3 s-1 of surface water. The water bottling plants considered in scenarios 4 and 5 have a production capacity of 200 m3 of bottled water per day. The LCA was performed with the software SimaPro®, using the CML 2 baseline method. The results showed how tap water consumption was the most favourable alternative, while bottled water presented the worst results due to the higher raw materials and energy inputs required for bottles manufacturing, especially in the case of glass bottles. The impacts generated by domestic reverse osmosis were between 10 and 24% higher than tap water alternative depending on the impact category. It was due to the higher electricity consumption. Reverse osmosis at the water treatment plant showed impacts nearly twice as high as domestic reverse osmosis systems scenario, mainly because of the higher energy inputs. Water treated by domestic reverse osmosis equipment was the most environmentally friendly solution for the improvement of tap water organoleptic characteristics. An economic analysis showed that this solution was between 8 and 19 times cheaper than bottled water.Peer ReviewedPostprint (author's final draft

Enhancement of microalgae anaerobic digestion by thermo-alkaline pretreatment with lime (CaO)

The aim of this study was to evaluate for the first time the effect of a thermo-alkaline pretreatment with lime (CaO) on microalgae anaerobic digestion. The pretreatment was carried out by adding different CaO doses (4 and 10%) at different temperatures (room temperature (25 °C), 55 and 72 °C). The exposure time was 4 days for pretreatments at 25 °C, and 24 h for pretreatments at 55 and 72 °C. Following, a biochemical methane potential test was conducted with pretreated and untreated microalgae. According to the results, the pretreatment enhanced proteins solubilisation by 32.4% and carbohydrates solubilisation by 31.4% with the highest lime dose and temperature (10% CaO and 72 °C). Furthermore, anaerobic digestion kinetics were improved in all cases (from 0.08 to 0.14 day- 1 for untreated and pretreated microalgae, respectively). The maximum biochemical methane potential increase (25%) was achieved with 10% CaO at 72 °C, in accordance with the highest biomass solubilisation. Thus, lime pretreatment appears as a potential strategy to improve microalgae anaerobic digestion.Peer ReviewedPostprint (author's final draft

Tecnologías apropiadas para desinfección de agua.

La desinfección de agua es una necesidad de primer orden en las emergencias. Reseñamos una investigación sobre una tecnología con este objetivo que se adapta al contexto ambiental, social y económico, además de resultar sencilla en la aplicación y manejo, a escala reducida; no tiene impacto ambiental, es de bajo costo, implica la participación de las comunidades y utiliza materiales fáciles de encontrar. Ello la hace apropiada para la zona de Colombia donde se trabaja, ya que sufre bloqueo económico.Peer Reviewe

Recent achievements in the production of biogas from microalgae

The final publication is available at Springer via http://dx.doi.org/10.1007/s12649-016-9604-3Microalgae are nowadays regarded as a potential biomass feedstock to help reducing our dependence on fossil fuels for transportation, electricity and heat generation. Besides, microalgae have been widely investigated as a source of chemicals, cosmetics and health products, as well as animal and human feed. Among the cutting-edge applications of microalgae biomass, anaerobic digestion has shown promising results in terms of (bio)methane production. The interest of this process lies on its potential integration within the microalgae biorefinery concept, providing on the one hand a source of bioenergy, and on the other hand nutrients (nitrogen, phosphorus and CO2) and water for microalgae cultivation. This article reports the main findings in the field, highlighting the options to increase the (bio)methane production of microalgae (i.e. pretreatment and co-digestion) and bottlenecks of the technology. Finally, energy, economic and environmental aspects are considered.Peer ReviewedPostprint (author's final draft

Impacts of photovoltaic power source intermittence on a distribution network

The integration of the photovoltaic (PV) solar systems into distribution networks has brought new challenges to the network planners. One of the most interesting is to prevent the impacts of the PV intermittent character on the steady state system operation conditions. This work is aimed to investigate such effect on voltage performance, conventional generator daily behavior and automatic voltage regulator operation. Simulations were conducted on a 33-bus IEEE radial distribution power system. In order to provide a reliable study, a real PV power profile was considered. Obtained results over a period of 24 hours revealed that the PV integration contributes to an enhancement of the overall voltage profile, a considerable saving in the total amount of the produced active power and a reduction of power losses. However, the PV intermittent character causes significant transformation in buses voltages daily profiles as well as changes in production plan. To sum up, this paper reports the alterations, caused by the PV source intermittence, which must be taken into consideration by the distribution networks planners to maintain the overall network parameters within safe operating conditio

Constructed wetlands for winery wastewater treatment: a comparative Life Cycle Assessment

A Life Cycle Assessment was carried out in order to assess the environmental performance of constructed wetland systems for winery wastewater treatment. In particular, six scenarios which included the most common winery wastewater treatment and management options in South-Western Europe, namely third-party management and activated sludge systems, were compared. Results showed that the constructed wetland scenarios were the most environmentally friendly alternatives, while the third-party management was the worst scenario followed by the activated sludge systems. Specifically, the potential environmental impacts of the constructed wetlands scenarios were 1.5–180 and 1–10 times lower compared to those generated by the third-party and activated sludge scenarios, respectively. Thus, under the considered circumstances, constructed wetlands showed to be an environmentally friendly technology which helps reducing environmental impacts associated with winery wastewater treatment by treating winery waste on-site with low energy and chemicals consumption.Peer ReviewedPostprint (author's final draft

A multi-criteria decision support tool for the assessment of household biogas digester programmes in rural areas. A case study in Peru

Household biogas digesters are a sustainable technology that can help rural families of low income countries meeting their basic energy needs and improving their standard of living. However, household biogas digester programmes are often promoted without any systematic planning which might help to overcome several challenges for household digesters dissemination (e.g. lack of stakeholders’ involvement, investment cost, technology reliability and durability, lack of site-specific designs). The aim of this study is to develop and validate, for the first time, a multi-criteria decision support tool for the assessment of household biogas digester programmes in rural areas of Latin America. The method is divided into three decision levels. First of all, the rural communities where household digesters may be implemented are evaluated and prioritized. Secondly, the most appropriate digester model (i.e. masonry or plastic tubular digester) is selected. Finally, the most appropriate household digester design (e.g. volume, materials) is identified considering local conditions and beneficiaries’ needs. For that, a set of technical, environmental and socio-economic criteria were defined and weighted by stakeholders at all the decision levels. Furthermore, the tool was validated using three case studies dealing with the implementation of household anaerobic digesters in rural areas of the Peruvian Andes in order to show how it can assist non-profit organizations designing sustainable and successful biogas digester programmes.Postprint (author's final draft