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Ammonia Emissions from Swiss Agriculture and their Effects on Atmospheric Chemistry and Ecosystems
Get PDFAmmonia (NH3) is an important atmospheric pollutant due to its contribution to secondary inorganic aerosol formation and its deposition and impacts on (semi-)natural ecosystems. Therefore various efforts have been made to limit emissions to the atmosphere. The predominant emission source in Switzerland is livestock agriculture, wherein NH3 is volatilised from ammonium contained in animal manure. While modelled NH3 emissions based on agricultural activity data indicate a minor decrease since 2000, concentration measurements do not reflect this trend. This can at least partly be attributed to a decline in the transformation of NH3 to particulate ammonium due to significantly decreased emission of oxidised nitrogen and sulfur compounds in the past decade. The partitioning between the gaseous and the particulate phase also determines the deposition pathway (dry or wet deposition) and thus the average lifetime and transport distance in the atmosphere. Gaseous NH3 is subject to fast dry deposition and is deposited preferentially to ecosystems close to the source. Once deposited into an ecosystem, NH3 leads to eutrophication and acidification of water and soils, which change the plant community composition and microbial functioning, especially in N-sensitive ecosystems. Although NH3 can also cause direct toxicity to plants, assessments of ecosystem impacts are generally collated using the critical load approach, which includes the input of all N compounds. These reveal that in 2020, 87% of forests, 94% of raised bogs, 74% of fens, and 42% of dry mountain grasslands likely experienced adverse impacts from N exceedances in Switzerland. To improve this situation, considerable NH3 emission abatement efforts are needed in the future
The PFAS Problem in the Context of Organofluorine Chemistry Research and Teaching: Chemical Education
No full textTeaching the rich and unique chemistry of poly- and perfluorinated organic compounds should go hand-in-hand with the awareness of their future impact on environment and health
History of Atmospheric Chemistry in Switzerland
Get PDFThis paper presents an overview on atmospheric chemistry, beginning with international aspects since the Roman Empire, and then focusing on the developments in Switzerland. Finally, the institutions dealing with atmospheric chemistry along with relevant scientists are briefly described
Electrified Enhanced Recovery of Lithium from Unconventional Sources
Get PDFDemand for lithium is expected to quadruple by the end of the decade. Without new sources of production, the supply-demand curve is expected to invert. Traditional geological reserves will not be able to meet the anticipated gap, thus unconventional sources of lithium will need to be utilized, setting the stage for fierce competition for perhaps the most critical of mineral resources required for the energy transition. Direct Lithium Extraction refers to the umbrella of technologies being developed to access lithium from unconventional sources. Electrochemical extraction offers significant promise for its selectivity and low operating cost when coupled with renewable energy. This review aims to describe materials and process design considerations for electrochemical extraction of lithium from aqueous sources with a specific emphasis on ζ-V2O5 designed in our research group as an insertion host. We point to specific strategies for improving capacity and selectivity for electrochemical lithium extraction based on materials design across length scales. Strategies range from site-selective modification of insertion hosts to controlled tortuosity of ion diffusion pathways in porous electrode architectures. Electrochemical lithium extraction from unconventional sources stands poised to be a linchpin of a sustainable economy when coupled with cleaning of wastewater, hydrogen generation, and recovery of ancillary critical metals
Exploring and Controlling Chemistry Using Quantum Logic
Get PDFOver the past years, the development of experimental techniques for the coherent manipulation and control of isolated quantum systems has made impressive progress. Such ‘quantum-logic’ methods are also highly attractive in a chemical context in view of unravelling and controlling the quantum dynamics of molecular collisions and chemical reactions. Quantum technologies have the potential to transform the way chemical dynamics are investigated – by providing highly sensitive methods for state readout and spectroscopy, by opening up new pathways for the quantum-state preparation of molecules and by enabling an improved control of their microscopic behavior on the single-particle level. However, for complex quantum systems like molecules, these techniques are still in their infancy and their considerable potential remains to be unlocked. The aim of the present research program supported by an Advanced Grant of the Swiss National Science Foundation is to merge the fields of quantum science and chemical dynamics by advancing quantum technologies to polyatomic molecular ions and by applying them to the study of ion-molecule collisions and chemical reactions. In this article, we review the salient experimental methods as well as prospects and challenges in the development of molecular quantum technologies and their applications to chemistry
Systematic Development of Peptide-Based Biostimulants from Whey Protein Hydrolysates: FH-HES (Universities of Applied Sciences)
No full textDue to global warming, agricultural production systems are exposed to increasing abiotic stresses, which threaten an economically and environmentally sustainable food production. Innovative environmentally friendly solutions are needed to cope with climate-related risks and to reduce the use of high amounts of synthetic agrochemicals. A promising solution to foster sustainable agriculture involves the use of biostimulants. This strategy, however, is not adopted by the industry to a great degree due to the scarce number of reproducible effects observed in published studies as well as the lack of fundamental knowledge about their mode of action. Biostimulants are substances that positively impact plant physiology by enhancing growth, improving fruit quality, and increasing stress resilience. Among these, protein hydrolysates stand out as a particularly promising category. However, their precise mechanisms of action and the optimal conditions for their application are still not fully understood. This project aims to develop peptide-based biostimulants in a reproducible manner, ensuring their availability for use in plant model systems under strictly controlled conditions. To achieve this, various protein hydrolysates will be produced through the enzymatic hydrolysis of whey, a by-product of cheese production. These hydrolysates will be employed in subsequent studies within plant model systems
