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To assess the sustainability of waste management scenario with energy recovery, it is necessary to carry out an adequate analysis of all influential criteria. The main problem in the analysis is to determine the indicators that clearly and fully sublimate the most important influential factors. The model for the assessment of the sustainability of waste treatment scenarios based on multi-criteria analysis AHP (analytic hierarchy process) method is developed. The model predicts an increase in the number of indicators, if it found that a selected number of indicators are not sufficient to distinguish between scenarios and new criterion for the selection of indicators: the relevance of the indicator for certain waste treatment. The model is verified in the case study the city of Nis. Four scenarios were selected and examined: business as usual scenario (landfilling of waste) and the other are created as scenarios with energy recovery and recourses preserving: composting organic waste with recycling inorganic waste, incineration of waste and anaerobic digestion of waste. The assessment of the sustainability of waste treatment scenarios was made in several steps. It is found that the best sustainable scenario is composting of organic and recycling of inorganic waste.

The future performance of the widely abundant European beech (Fagus sylvatica L.) across its ecological amplitude is uncertain. Although beech is considered drought-sensitive and thus negatively affected by drought events, scientific evidence indicating increasing drought vulnerability under climate change on a cross-regional scale remains elusive. While evaluating changes in climate sensitivity of secondary growth offers a promising avenue, studies from productive, closed-canopy forests suffer from knowledge gaps, especially regarding the natural variability of climate sensitivity and how it relates to radial growth as an indicator of tree vitality. Since beech is sensitive to drought, we in this study use a drought index as a climate variable to account for the combined effects of temperature and water availability and explore how the drought sensitivity of secondary growth varies temporally in dependence on growth variability, growth trends, and climatic water availability across the species' ecological amplitude. Our results show that drought sensitivity is highly variable and non-stationary, though consistently higher at dry sites compared to moist sites. Increasing drought sensitivity can largely be explained by increasing climatic aridity, especially as it is exacerbated by climate change and trees' rank progression within forest communities, as (co-)dominant trees are more sensitive to extra-canopy climatic conditions than trees embedded in understories. However, during the driest periods of the 20th century, growth showed clear signs of being decoupled from climate. This may indicate fundamental changes in system behavior and be early-warning signals of decreasing drought tolerance. The multiple significant interaction terms in our model elucidate the complexity of European beech's drought sensitivity, which needs to be taken into consideration when assessing this species' response to climate change.

Ethiopia is growing fast, and the country has a dire need of energy. To avoid environmental damages, however, Ethiopia is looking for green energy polices, including hydropower exploitation, with large water availability (i.e., the Blue Nile, the greatest tributary of Nile river). Besides other dams on the Omo river, the GIBE family, Ethiopia is now building the largest hydropower plant of Africa, the GERD (Grand Ethiopian Renaissance Dam), on the Blue Nile river, leading to tensions between Ethiopia, and Egypt, due to potentially conflictive water management. In addition, present and prospective climate change may affect reservoirs’ operation, and this thereby is relevant for downstream water users, population, and environment. Here, we evaluated water management for the GERD, and GIBE III dams, under present, and future hydrological conditions until 2100. We used two models, namely, Poli-Hydro and Poli-Power, to describe (i) hydrological budget, and flow routing and (ii) optimal/maximum hydropower production from the two dams, under unconstrained (i.e., no release downstream besides MIF) and constrained (i.e., with fair release downstream) simulation. We then used climate change scenarios from the reports CMIP5/6 of the Intergovernmental Panel on Climate Change (IPCC) until 2100, to assess future hydropower production. Our results demonstrate that the filling phase of the GERD, particularly critical, have optimal filling time of 5 years or so. Stream flows at GERD could be greater than the present ones (control run CR) at half century (2050–2059), but there could be large decrease at the end of century (2090–2099). Energy production at half century may increase, and then decrease until the end of century. In GIBE III discharges would increase both at half century, and at the end of century, and so would energy production. Constrained, and unconstrained simulation provide in practice similar results, suggesting potential for shared water management in both plants.

The growing threats of global warming and climate change are two of the main concerns of world society. The culprits are greenhouse gas emissions, which mainly result from the combustion of fossil fuels (i.e. the consumption and production of energy from oil, coal and natural gas), a well-known issue at the centre of many climate change debates. The European Parliament has endorsed the EU target of zero net greenhouse gas emissions by 2050 [1]. It is therefore essential to provide for sustainable energy development strategies such as biomass. The valorization of biomass makes it possible to alleviate environmental problems. we are able to obtain energy from what was, until recently, considered to be waste. this article assesses the contribution that chestnut skin biomass makes, in energy, environmental and economic terms, to the production process of the company Monsurgel Lda. The results show that the chestnut skin can contribute to an energy saving with a good investment payback time and also an environment contribution with the CO2 reduction. Proceedings of the 29th European Biomass Conference and Exhibition, 26-29 April 2021, Online, pp. 515-521

Abstract The increasing worldwide energy demand is rising the interest on alternative power production technologies based on renewable and emission-free energy sources. In this regard, the closed-loop reverse electrodialysis heat engine is a promising technology with the potential to convert low-grade heat into electric power. The reverse electrodialysis technology has been under investigation in the last years to explore the real potentials for energy generation from natural and artificial solutions, and recent works have been addressing also the potential of its coupling with regeneration strategies, looking at medium and large energy supply purposes. In this work, for the first time, a comprehensive exergy analysis at component level is applied to a reverse electrodialysis heat engine with multi-effect distillation in order to determine the real capability of the waste heat to power conversion, identifying and quantifying the sources of exergy destruction. In particular, sensitivity analyses have been performed to assess the influence of the main operating conditions (i.e. solutions concentration and velocity) and design features (aspect ratio of the pile), characterizing the most advantageous scenarios and including the effect of new generations of membranes. Results show that the multi-effect distillation unit is the main source of exergy destruction. Also, using high-performing membranes, inlet solutions concentration and velocity of 4.5–0.01 mol/L and 0.2–0.36 cm/s, respectively, a global exergy efficiency of 24% is reached for the system, proving the high potential of this technology to sustainably convert waste heat into power.