• Energy Research
• Restricted close
• Embargo close
• DE close
• EU close
• BE close

Eutrophication of lakes leading to loss of submersed macrophytes and higher turbidity is a worldwide phenomenon, attributed to excessive loading of phosphorus (P). However, recently, the role of nitrogen (N) for macrophyte recession has received increasing attention. Due to the close relationship between N and P loading, disentanglement of the specific effects of these two nutrients is often difficult, and some controversy still exists as to the effects of N. We studied the effects of N on submersed macrophytes represented by Vallisneria natans (Lour.) Hara in pots positioned at three depths (0.4 m, 0.8 m, and 1.2 m to form a gradient of underwater light conditions) in 10 large ponds having moderate concentrations of P (TP 0.03 ± 0.04 mg L(-1)) and five targeted concentrations of total nitrogen (TN) (0.5, 2, 10, 20, and 100 mg L(-1)), there were two ponds for each treatment. To study the potential shading effects of other primary producers, we also measured the biomass of phytoplankton (ChlaPhyt) and periphyton (ChlaPeri) expressed as chlorophyll a. We found that leaf length, leaf mass, and root length of macrophytes declined with increasing concentrations of TN and ammonium, while shoot number and root mass did not. All the measured growth indices of macrophytes declined significantly with ChlaPhyt, while none were significantly related to ChlaPeri. Neither ChlaPhyt nor ChlaPeri were, however, significantly negatively related to the various N concentrations. Our results indicate that shading by phytoplankton unrelated to the variation in N loading and perhaps toxic stress exerted by high nitrogen were responsible for the decline in macrophyte growth.

In industrialized countries, large amounts of mineral wastes are produced. They are re-used in various ways, particularly in road and earth constructions, substituting primary resources such as gravel. However, they may also contain pollutants, such as heavy metals, which may be leached to the groundwater. The toxic impacts of these emissions are so far often neglected within Life Cycle Assessments (LCA) of products or waste treatment services and thus, potentially large environmental impacts are currently missed. This study aims at closing this gap by assessing the ecotoxic impacts of heavy metal leaching from industrial mineral wastes in road and earth constructions. The flows of metals such as Sb, As, Pb, Cd, Cr, Cu, Mo, Ni, V and Zn originating from three typical constructions to the environment are quantified, their fate in the environment is assessed and potential ecotoxic effects evaluated. For our reference country, Germany, the industrial wastes that are applied as Granular Secondary Construction Material (GSCM) carry more than 45,000 t of diverse heavy metals per year. Depending on the material quality and construction type applied, up to 150 t of heavy metals may leach to the environment within the first 100 years after construction. Heavy metal retardation in subsoil can potentially reduce the fate to groundwater by up to 100%. One major challenge of integrating leaching from constructions into macro-scale LCA frameworks is the high variability in micro-scale technical and geographical factors, such as material qualities, construction types and soil types. In our work, we consider a broad range of parameter values in the modeling of leaching and fate. This allows distinguishing between the impacts of various road constructions, as well as sites with different soil properties. The findings of this study promote the quantitative consideration of environmental impacts of long-term leaching in Life Cycle Assessment, complementing site-specific risk assessment, for the design of waste management strategies, particularly in the construction sector.

Network temperatures in district heating systems are important operational factors for obtaining efficient performance. A low network return temperature allows for the recovery of low-grade heat from assets such as condensing boilers, waste incineration, geothermal sources and industrial waste heat. Fluctuations in heating and cooling demands affect the return temperatures of the building substations and in the network. This variability impacts the economic viability and environmental sustainability of the entire system. This paper presents a nonlinear optimization strategy to maintain sufficient energy flows in the network's primary and secondary circuits to achieve low return temperatures from all substations in the network. The defined optimization strategy incorporates the thermodynamic model of the substation and building heating system as opposed to traditional weather-based supply temperature adjustments. The estimated heat demands and tariffs, CO2 penalties are inputs used by the optimizer to find theoptimal solution. The total operational expenditure for electricity and gas consumption shows an 18% reduction with 8% reduction in emissions and 6% efficiency improvement when compared with the measured weather-based approach. The developed strategy will aid the network operators in the economic dispatch of heat generation while ensuring the user's thermal comfort.

| openaire: EC/H2020/856602/EU//FINEST TWINS Funding Information: This work has been supported by the European Commission through the H2020 project Finest Twins grant No. 856602; and by the Estonian Ministry of Education and Research and European Regional Fund grant 2014-2020.4.01.20-0289. Additional support was acquired from the Estonian Research Council grant PSG739. Publisher Copyright: © 2023 Increasing use of volatile renewable energy sources causes challenges in balancing supply and demand. Therefore, demand-side flexibility has rising importance for system operators and balancing authorities. Flexibility management methods are needed to integrate loads like ventilation systems of different buildings (e.g., residential and commercial) into flexibility service. However, the available methods described in research papers require further development for implementation in practice. Heating and cooling systems have received much attention from researchers, but the potential of ventilation systems has been left out of focus. Therefore, this paper provides a complete set of novel flexibility management methods for ventilation systems created from an aggregator's viewpoint. The flexibility is quantified through capacity (e.i. the amount of power consumption that can be altered), forced ventilation rate duration, and the tendered price for the service. The proposed methods were tested on a building model constructed and simulated in IDA ICE. The data processing and flexibility management methods were applied in MATLAB. Two types of ventilation systems with different sensor configurations were considered: constant and variable air volume. Forced ventilation rate duration is calculated using energy and mass balance analysis where the root means squared error was 10 to 33 min, depending on the system type, measured parameter, and sensor location. The flexibility service pricing model was tested on the 2022 years' manual frequency restoration reserve (mFRR) activation and balance energy market data. Peer reviewed

Sustainable agriculture leads today to important questions about the diversification of agricultural production and sources of income for farmers, the use of rural and arable land for food and non-food crops, the contribution of agriculture to climate change fighting and the supply of renewable energy. Bioenergy from agriculture is at the heart of these concerns, integrating sustainable development key components: environment and climate change, energy economics and energy supply, agriculture, rural and social development. The lack of primary and reliable data on bioenergy externalities from agriculture and the lack of decision-making tools are important non-technological barriers to the development of bioenergy from agriculture on a large scale, and, consequently, to the achievement of the national and regional objectives of sustainable development with respect to greenhouse gas mitigation, secure and diversified energy supply, rural development and employment and the future of agriculture. Furthermore, the recent worldwide controversies about transport biofuels, food shortages and increasing prices have demonstrated the urgent need for sustainability criteria applied to biofuels and bioenergy. Within this current sustainable development framework, a project entitled TEXBIAG integrating experts from 4 research institutions is financed by the Belgian Science Policy. The final objective of this project is to lead to an actual and significant contribution of bioenergy from agriculture to the mitigation of greenhouse gas emissions, to a secure and diversified energy supply and to farmers' incomes and rural development. To reach this final objective, the project develops three specific tools: (1) a database of primary quantitative data related to environmental and socio-economic impacts of bioenergy from agriculture integrating biomass logistics; (2) a mathematical model monetizing bioenergy externalities from agriculture; and (3) a prediction tool assessing the impacts of political decisions made in the framework ofthe development of bioenergy from agriculture on different economic sectors (energy, agriculture, industry, and environment). An integrated interface tool will be programmed where access to and update of the three tools will be prepared. The project methodology will be conducted for a given number of scenarios with sensitivity analysis wherever possible. The three main target groups that will benefit from the project are: the government officials and policy makers in the field of agriculture, energy and environment in Belgium and its two main regions, the small, medium and large energy companies and the agricultural sector

Abstract Thermal cross-linking in presence of residual solvent dimethylsulfoxide without any addition of cross-linker molecules is described. This elegant method increases spectacularly the mechanical and hydrolytic stability of sulfonated aromatic polymers (SAP), making them suitable for use in liquid water also at 145 °C. Data on water uptake, mechanical properties and proton conductivity are presented and discussed from a bond energy point of view. The developed method is also inexpensive, being incorporated in the normal membrane casting procedure. This opens new horizons and hitherto conventionally disregarded SAP membranes should be reconsidered as fuel cell membranes.

The Poster proposes a research agenda for the creation of knowledge about the potential of Digital Product Passports (DPPs) as a means to promote the sustainability of the textiles sector. Analysis is called for to transition to a more sustainable society by focusing on the 1) Textiles ecosystem: relevant stakeholders and their interrelationships 2) Trust, transparency, reliability, sustainability, and information 3) DPPs as an information system 4) Data requirements for DPPs and 5) The societal impacts of DPPs.