Waste products from the steel industry with NiO as additive as oxygen carrier for chemical-looping combustion

Fe₂O₃-containing waste materials from the steel industry are proposed as oxygen carrier for chemical-looping combustion. Three such materials, red iron oxide, brown iron oxide and iron oxide scales, have been examined by oxidation and reduction experiments in a batch fluidized-bed reactor at temperatures between 800 and 950 °C. NiO-based particles have been used as additive, in order to examine if it is possible to utilize the catalytic properties of metallic Ni to facilitate decomposition of hydrocarbons into more reactive combustion intermediates such as CO and H₂. The experiments indicated modest reactivity between the waste materials and CH₄, which was used as reducing gas. Adding small amounts of NiO-based particles to the sample increased the yield of CO₂ in a standard experiment, typically by a factor of 1.5–3.5. The fraction of unconverted fuel typically was reduced by 70–90%. The conversion of CH₄ to CO₂ was 94% at best, corresponding to a combustion efficiency of 96%. This was achieved using a bed mass corresponding to 57 kg oxygen carrier per MW fuel, of which only 5 wt% was NiO-based synthetic particles. The different materials fared differently well during the experiments. Red iron oxide was fairly stable, while brown iron oxide was soft and subject to considerable erosion. Iron oxide scales experienced increased reactivity and porosity as function of the numbers of reduction cycles.     

Monofluorinated analogues of polychlorinated biphenyls (F-PCBs): synthesis using the Suzuki-coupling, characterization, specific properties and intended use

An improved method, a palladium-catalyzed cross-coupling reaction the so-called Suzuki-coupling, was used to synthesize 19 monofluorinated analogues (F-PCBs) of polychlorinated biphenyls (PCBs), including analogues of PCBs 28, 52 and 81. The coupling of chlorinated and/or fluorinated isomers of aryl boronic acids with bromo- and/or iodobenzenes gave the desired F-PCB congeners in good to excellent yields. The self-coupling product of the aryl boronic acids was the major impurity, but this limitation could be minimized. The influence of ortho-substitution by chlorine on the reaction time was studied in detail. The F-PCBs were characterized by means of ¹H and ¹⁹F NMR and mass spectrometry (MS). F-PCBs show remarkably similar characteristics in many aspects to those of the corresponding non-fluorinated parent PCBs. Since fluorine is generally resistant to degradation, once incorporated into a substrate it functions as an indelible label that can be used to monitor structures and dynamics. F-PCBs may prove their usefulness as markers and tracers in mechanistic and toxicological studies. The aim of further research will be to test the suitability of fluorine as a sensitive probe in a broad range of applications, including synthesis, analytical, mechanistic and toxicological studies.     

Land use change in Southern Romania after the collapse of socialism

The drastic socio-economic and political changes that occurred after the breakdown of socialism in Eastern Europe triggered widespread land use change, including cropland abandonment and forest cover changes. Yet the rates and spatial patterns of post-socialist land use change remain largely unclear. We used Landsat TM/ETM+ images to classify land cover maps and assess landscape pattern changes from 1990 to 2005 in Argeş County, Southern Romania. Cropland abandonment was the most widespread change (21.1% abandonment rate), likely due to declining returns from farming, tenure insecurity, and demographic developments during transition. Forest cover and forest fragmentation remained remarkably stable during transition, despite widespread ownership transfers. Cropland abandonment provides opportunities for increased carbon sequestration, but threatens cultural landscapes and biodiversity. Continued monitoring is important for assessing whether abandoned croplands will eventually reforest or be put back into production and to better understand the consequences of post-socialist land use change for ecosystems and biodiversity.     

Post-socialist forest disturbance in the Carpathian border region of Poland, Slovakia, and Ukraine.

Forests provide important ecosystem services, and protected areas around the world are intended to reduce human disturbance on forests. The question is how forest cover is changing in different parts of the world, why some areas are more frequently disturbed, and if protected areas are effective in limiting anthropogenic forest disturbance. The Carpathians are Eastern Europe's largest contiguous forest ecosystem and are a hotspot of biodiversity. Eastern Europe has undergone dramatic changes in political and socioeconomic structures since 1990, when socialistic state economies transitioned toward market economies. However, the effects of the political and economic transition on Carpathian forests remain largely unknown. Our goals were to compare post-socialist forest disturbance and to assess the effectiveness of protected areas in the border triangle of Poland, Slovakia, and Ukraine, to better understand the role of broadscale political and socioeconomic factors. Forest disturbances were assessed using the forest disturbance index derived from Landsat MSS/TM/ETM+ images from 1978 to 2000. Our results showed increased harvesting in all three countries (up to 1.8 times) in 1988-1994, right after the system change. Forest disturbance rates differed markedly among countries (disturbance rates in Ukraine were 4.5 times higher than in Poland, and those in Slovakia were 4.3 times higher than in Poland), and in Ukraine, harvests tended to occur at higher elevations. Forest fragmentation increased in all three countries but experienced a stronger increase in Slovakia and Ukraine (approximately 5% decrease in core forest) than in Poland. Protected areas were most effective in Poland and in Slovakia, where harvesting rates dropped markedly (by nearly an order of magnitude in Slovakia) after protected areas were designated. In Ukraine, harvesting rates inside and outside protected areas did not differ appreciably, and harvests were widespread immediately before the designation of protected areas. In summary, the socioeconomic changes in Eastern Europe that occurred since 1990 had strong effects on forest disturbance. Differences in disturbance rates among countries appear to be most closely related to broadscale socioeconomic conditions, forest management practices, forest policies, and the strength of institutions. We suggest that such factors may be equally important in other regions of the world.     

250-year records of mercury and trace element deposition in two lakes from Cajas National Park,SW Ecuadorian Andes

Environmental Science and Pollution Research - Historical records of trace elements in lake sediments provide source-to-sink information about potentially toxic pollutants across space and time. We...     

Incorporating stakeholders’ preferences into a multi-criteria framework for planning large-scale Nature-Based Solutions

Hydro-meteorological risks are a growing issue for societies, economies and environments around the world. An effective, sustainable response to such risks and their future uncertainty requires a paradigm shift in our research and practical efforts. In this respect, Nature-Based Solutions (NBSs) offer the potential to achieve a more effective and flexible response to hydro-meteorological risks while also enhancing human well-being and biodiversity. The present paper describes a new methodology that incorporates stakeholders’ preferences into a multi-criteria analysis framework, as part of a tool for selecting risk mitigation measures. The methodology has been applied to Tamnava river basin in Serbia and Nangang river basin in Taiwan within the EC-funded RECONECT project. The results highlight the importance of involving stakeholders in the early stages of projects in order to achieve successful implementation of NBSs. The methodology can assist decision-makers in formulating desirable benefits and co-benefits and can enable a systematic and transparent NBSs planning process.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01419-4) contains supplementary material, which is available to authorized users.     

Workshop report on the extraction of foetal DNA from maternal plasma

Objective Cell free foetal DNA (cff DNA) extracted from maternal plasma is now recognized as a potential source for prenatal diagnosis but the methodology is currently not well standardized. To evaluate different manual and automated DNA extraction methods with a view to developing standards, an International Workshop was performed. Methods Three plasma pools from RhD-negative pregnant women, a DNA standard, real-time-PCR protocol, primers and probes for RHD were sent to 12 laboratories and also to one company (Qiagen, Hilden, Germany). In pre-tests, pool 3 showed a low cff DNA concentration, pool 1 showed a higher concentration and pool 2 an intermediate concentration. Results The QIAamp DSP Virus Kit, the High Pure PCR Template Preparation Kit, an in-house protocol using the QIAamp DNA Blood Mini Kit, the CST genomic DNA purification kit, the Magna Pure LC, the MDx, the M48, the EZ1 and an in-house protocol using magnetic beads for manual and automated extraction were the methods that were able to reliably detect foetal RHD. The best results were obtained with the QIAamp DSP Virus Kit. The QIAamp DNA Blood Mini Kit showed very comparable results in laboratories that followed the manufacturer's protocol and started with ≥ 500 µL plasma. One participant using the QIAamp DNA Blood Midi Kit failed to detect reliably RHD in pool 3. Conclusions This workshop initiated a standardization process for extraction of cff DNA in maternal plasma. The highest yield was obtained by the QIAamp DSP Virus Kit, a result that will be evaluated in more detail in future studies. Copyright © 2007 John Wiley & Sons, Ltd.     

Renewable hydrogen production: a technical evaluation based on process simulation

An evaluation of different hydrogen production technologies based on renewable raw materials and/or renewable energy is presented. The evaluation comprises alkaline electrolysis, steam reforming of both biogas and gasification gas, the coupled dark and photo fermentation as well as the coupled dark and biogas fermentation. Each technology is investigated with different plant layouts and/or different raw materials. All examined technologies are designed to produce hydrogen in a quality suitable for the use in mobile fuel cells. The presented evaluation is based on the hydrogen production efficiency and the energy efficiency of the processes.     

Concentrating solar power in a sustainable future electricity mix

The capacity of a concentrating solar thermal power (CSP) plant can be considered flexible and firm, just like that of a conventional steam cycle power station. Periods without sunshine can be bridged by thermal energy storage or fuel, enabling a CSP plant to deliver power on demand at any time. To this technical quality is added the economic quality of electricity costs that will be stable for a lifetime because they are mainly composed of capital costs, spare parts and personnel. CSP is competitive with power from fuel oil and moving to break even in costs with natural gas by around 2020 and steam coal by around 2025. Carbon dioxide emissions of 10–40 tons/GWh, land use of 250–550 m²/GWh and water consumption of 250 m³/GWh (using dry cooling) compare favorably with other energy sources. Environmental benefits, the technical imperative of firm and at the same time flexible power supply, and the economic targets of affordability and cost stability are the main reasons for a significant role for CSP in a sustainable future electricity mix. Two case studies show the different roles CSP can play north and south of the Mediterranean Sea, in one case importing CSP to Germany for flexible power and in the second case using CSP in Jordan to provide firm and at the same time renewable power capacity for the quickly growing electricity demand.