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A procedure for the design of an aerobic cometabolic process for the on-site degradation of chlorinated solvents in a packed bed reactor was developed using groundwater from an aquifer contaminated by trichloroethylene (TCE) and 1,1,2,2-tetrachloroethane (TeCA). The work led to the selection of butane among five tested growth substrates, and to the development and characterization from the site's indigenous biomass of a suspended-cell consortium capable to degrade TCE (first order constant: 96 L gprotein(-1) day(-1) at 30 °C and 4.3 L gprotein(-1) day(-1) at 15 °C) with a 90 % mineralization of the organic chlorine. The consortium immobilization had strong effects on the butane and TCE degradation rates. The microbial community structure was slightly changed by a temperature shift from 30 to 15 °C, but remarkably affected by biomass adhesion. Given the higher TCE normalized degradation rate (0.59 day(-1) at 15 °C) and attached biomass concentration (0.13 gprotein Lbioreactor(-1) at 15 °C) attained, the porous ceramic carrier Biomax was selected as the best option for the packed bed reactor process. The low TeCA degradation rate exhibited by the developed consortium suggested the inclusion of a chemical pre-treatment based on the TeCA to TCE conversion via β-elimination, a very fast reaction at alkaline pH. To the best of the authors' knowledge, this represents the first attempt to develop a procedure for the development of a packed bed reactor process for the aerobic cometabolism of chlorinated solvents.

Abstract Decarbonizing world economies implies the deployment of “green technologies”, meaning a renovation of the energy sector towards using renewable sources and zero emission transport technologies. This renovation will require huge amounts of raw materials, some of them with high supply risks. To assess such risks a new methodology is proposed, identifying possible bottlenecks of future demand versus geological availability. This has been applied to the world development of wind power, solar photovoltaic, solar thermal power and passenger electric vehicles for the 2016–2050 time period under a business as usual scenario considering the impact on 31 different raw materials. As a result, 13 elements were identified to have very high or high risk, meaning that these could generate bottlenecks in the future: cadmium, chromium, cobalt, copper, gallium, indium, lithium, manganese, nickel, silver, tellurium, tin and zinc. Tellurium, which is mostly demanded to manufacture solar photovoltaic cells, presents the highest risk. To overcome these constraints, measures consisting on improving recycling rates from 0.1% to 4.6% per year could avoid material shortages or restrictions in green technologies. For instance, lithium recycling rate should increase from 1% to 4.8% in 2050. This study aims to serve as a guideline for developing eco-design and recycling strategies.

SummaryWater accounting is an unresolved issue in metabolism studies. Through epistemological analysis, we show that the problem resides in the conceptualization of social metabolism. Social metabolism has its origins in the analysis of societal energetics, which has led to an exclusive focus on society and a representation based on linear throughputs at a single scale. Whereas fossil energy resources constitute a mere stock flow for society, water constitutes a set of both funds and flows essential for the maintenance of the internal organization and stability of society and ecosystems. This means that societies and ecosystems need water for different reasons. Consequently, the analysis of water requires the simultaneous adoption of multiple narratives and scales. The development of hydrology toward a socio‐eco‐hydrology (SE‐hydrology) deals with this multidimensionality, but lacks a conceptualization of the coupled human‐water system useful to integrate the assessment of water processes at different rates and scales. We propose a conceptual framework, based on the multiscale integrated analysis of societal and ecosystem metabolism approach, that combines the perspectives of SE‐hydrology and social metabolism. This framework describes society and the embedding ecosystem as two distinct levels of the same hierarchical system (i.e., the socioecological system), expressing two distinct, but tightly interconnected, metabolic patterns (societal and ecosystem) at different spatiotemporal scales. Using food grain production in Punjab as an example, we show that this framework can accommodate the multiple interpretations of social metabolism found in different scientific fields.

Development of sustainable energy is a pivotal step towards solutions for today's global challenges, including mitigating the progression of climate change and reducing dependence on fossil fuels. Biofuels derived from agricultural crops have already been commercialized. However the impacts on environmental sustainability and food supply have raised ethical questions about the current practices. Cyanobacteria have attracted interest as an alternative means for sustainable energy productions. Being aquatic photoautotrophs they can be cultivated in non-arable lands and do not compete for land for food production. Their rich genetic resources offer means to engineer metabolic pathways for synthesis of valuable bio-based products. Currently the major obstacle in industrial-scale exploitation of cyanobacteria as the economically sustainable production hosts is low yields. Much effort has been made to improve the carbon fixation and manipulating the carbon allocation in cyanobacteria and their evolutionary photosynthetic relatives, algae and plants. This review aims at providing an overview of the recent progress in the bioengineering of carbon fixation and allocation in cyanobacteria; wherever relevant, the progress made in plants and algae is also discussed as an inspiration for future application in cyanobacteria.

Abstract Europe's energy transition journey involves more than a straightforward setting of goals, and designing policies and measures to achieve these. A successful energy transition relies on multi-faceted dynamics. This study identifies the barriers and motivators affecting the energy transition from the perspective of three decision-making levels: a) formal social units, b) collective decision-making units, and c) individual consumers engaging in joint contracts; and technological foci that constitute the core of EU Energy Efficiency Directive. We present a literature review that identifies approaches to the barriers and motivators before demonstrating the results of qualitative analysis on transcripts of 67 in-depth interviews and 15 focus groups across six EU member and associate countries. This study identifies emerging themes regarding the decision-making levels and technological foci, assesses the degree of alignment between the existing literature and the perspectives of these respondents from different decision-making levels, and suggests how these perspectives can be translated into policy recommendations. An important finding of the study is that barriers are frequently described as being confined to lower level collective decision-making units, whereas the transition to low carbon is deemed inevitable for higher levels. Therefore, in addition to communication, a significant role in enabling energy transition is played by personal and social factors, which should be considered in policy-making.

Transformation of coal-dependent regions in the European Union has received much lower research interest than industry decarbonisation. Moreover, even if territorial strategies are proposed, positive aspects are highlighted, while the risks are neglected or not addressed explicitly. In this context, we explore transition stakeholders’ beliefs and perception about political, economic, social, environmental and technological risks and opportunities for the coal-dependent region of Silesia (Poland) – the largest European coal region. A multidisciplinary and interdisciplinary assessment of risks and opportunities demonstrates that all stakeholders but NGOs consider the consequences of climate change-induced uncertainties unambiguously negative. The territorial analysis of Silesian counties based on the Prevalent Vulnerability Index scoring shows that virtually all counties with the ongoing coal mining activity are expected to face difficulties with adapting to changes.

Greenhouse gas emissions urgently need to be reduced. Even with a step up in mitigation, the goal of limiting global temperature rise to well below 2 °C remains challenging. Consequences of missing these goals are substantial, especially on regional scales. Because progress in the reduction of carbon dioxide emissions has been slow, climate engineering schemes are increasingly being discussed. But global schemes remain controversial and have important shortcomings. A reduction of global mean temperature through global-scale management of solar radiation could lead to strong regional disparities and affect rainfall patterns. On the other hand, active management of land radiative effects on a regional scale represents an alternative option of climate engineering that has been little discussed. Regional land radiative management could help to counteract warming, in particular hot extremes in densely populated and important agricultural regions. Regional land radiative management also raises some ethical issues, and its efficacy would be limited in time and space, depending on crop growing periods and constraints on agricultural management. But through its more regional focus and reliance on tested techniques, regional land radiative management avoids some of the main shortcomings associated with global radiation management. We argue that albedo-related climate benefits of land management should be considered more prominently when assessing regional-scale climate adaptation and mitigation as well as ecosystem services.

Wind energy is one of the key technologies to become independent of fossil fuels. Implementation of wind energy on a local level, however, has sometimes proved to be challenging and dealing with local acceptance of onshore wind turbines has become troublesome for some projects. Communication and public involvement are seen as strategies to prevent or respond to local opposition. This paper analyses the views of a variety of experts in wind energy on this matter. It focuses on eliciting their experiences with public participation measures. Furthermore, the perceived effectiveness of the measures for the social acceptance of wind energy projects is analysed. To do so, this paper draws on an expert survey among 207 individuals across Europe linked to wind energy projects. The analysis shows that negative reactions to wind farms are reported more frequently than positive reactions. In nearly 40% of cases, projects experience negative consequences on project development due to a lack of social acceptance, ranging from delays to changes in project plans and even termination. The vast majority of wind project developers respond to this by carrying out public participation activity at least sometimes. However, a much lower share does this systematically and the level of activity is low in early project phases. With regard to the relationship between project activities and project success, there is some support for the assumption that early and systematic involvement of the public and stakeholders is likely to reduce negative reactions.