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Forschergruppe (FOR) 1806: The Forgotten Part of Carbon Cycling: Organic Matter Storage and Turnover in Subsoils (SUBSOM), Biological Regulation of Subsoil C-cycling under Field Conditions

The nature of the microbial communities inhabiting the deeper soil horizons is largely unknown. It is also not clear why subsurface microorganisms do not make faster use of organic compounds under field conditions. The answer could be provided by a reciprocal soil transfer experiment studying the response of transferred soils to fluctuations in microclimate, organic inputs, and soil biota. The subproject P9 will be responsible for the establishment of reciprocal transfer experiments offering a strong link between subgroups interested in organic matter quality, transport of organic substances, as well as functions of the soil microbial community. A single, high molecular weight substrate (13C labelled cellulose) will be applied at two different levels in the pre-experiment to understand the dose-dependent reaction of soil microorganisms in transferred surface and sub-soils. Uniformly 13C labelled beech roots - representing complex substrates - will be used for the main reciprocal soil transfer experiment. We hypothesize that transferring soil cores between subsoil and surface soil as well as addition of labelled cellulose or roots will allow us to evaluate the relative impact of surface/subsurface habitat conditions and resource availability on abundance, function, and diversity of the soil microbial community. The second objective of the subproject is to understand whether minerals buried within different soil compartments (topsoil vs. subsoil) in the field contribute to creation of hot spots of microbial abundance and activity within a period of two to five years. We hypothesize that soil microorganisms colonize organo-mineral complexes depending on their nutritional composition and substrate availability. The existence of micro-habitat specific microbial communities could be important for short term carbon storage (1 to 6 years). The third objective is to understand the biogeography and function of soil microorganisms in different subsoils. Parent material as well as mineral composition might control niche differentiation during soil development. Depending on size and interconnectedness of niches, colonization and survival of soil microbial communities might be different in soils derived from loess, sand, terra fusca, or sandstone. From the methodological point of view, our specific interest is to place community composition into context with soil microbial functions in subsoils. Our subgroup will be responsible for determining the abundance, diversity, und function of soil microorganisms (13C microbial biomass, 13C PLFA, enzyme activities, DNA extraction followed by quantitative PCR). Quantitative PCR will be used to estimate total abundances of bacteria, archaea and fungi as well as abundances of specific groups of bacteria at high taxonomic levels. We will apply taxa specific bacterial primers because classes or phyla might be differentiated into ecological categories on the basis of their life strategies.

Screening-Studie zu gefährlichen Stoffen in Meeressäugern der Ostsee

Wie die HELCOM-Expertengruppe für Meeressäugetiere (EG MAMA; portal.helcom.fi, 2021) feststellt, liegen nur begrenzte Informationen über das Vorkommen, die (Öko-)Toxizität und die potenziellen gesundheitlichen Auswirkungen von Neuen Schadstoffen bei Meeressäugern vor. Neue Schadstoffe werden durch verschiedene anthropogene Aktivitäten in die Umwelt eingebracht, und einige dieser Stoffe haben das Potenzial, in Meeres-, Süßwasser- und/oder terrestrische Nahrungsnetze zu gelangen, wo sie sich anreichern können. Gegenwärtig fehlen häufig Informationen über die Exposition, und es besteht ein dringender Bedarf an ausreichenden Daten zum Vorkommen und die Auswirkungen, um CEC bewerten und gegebenenfalls Maßnahmen zur Risikominderung einleiten zu können. Ziel des Projekts war das Screening auf potenziell gefährliche Neue Schadstoffe in Meeressäugetieren aus der Ostsee unter Verwendung modernster analytischer Methoden für ein weitreichendes Ziel- und Verdachtsscreening. Zu diesem Zweck wurden 11 gepoolte Leber- und eine nicht gepoolte Muskelprobe von 11 Meeressäugern (Schweinswal (Phocoena phocoena), Gewöhnlicher Delphin (Delphinus delphis), Kegelrobbe (Halichoerus grypus), Seehund (Phoca vitulina)) von HELCOM-Vertragsparteien aus Deutschland, Schweden, Dänemark und Polen zur Verfügung gestellt. Die interessierenden Verunreinigungen wurden aus den gefriergetrockneten Matrizes mit Hilfe allgemeiner Extraktionsmethoden extrahiert, und die endgültigen Extrakte wurden sowohl mit Flüssig- als auch mit Gaschromatographie in Verbindung mit hochauflösender Massenspektrometrie (HRMS; LC-ESI-QToF und GC-APCI-QToF) analysiert. Die Proben wurden quantitativ auf das Vorhandensein von mehr als 2,500 organischen Schadstoffen untersucht, darunter Verbindungen verschiedener Klassen wie Arzneimittel, Kosmetika, Biozide, Pflanzenschutzmittel, illegale Drogen, Stimulanzien, Süßstoffe und Industriechemikalien (z. B. Per- und Polyfluoralkylsubstanzen (PFAS), Flammschutzmittel, Korrosionsinhibitoren, Weichmacher, Tenside) sowie deren Umwandlungsprodukte (TPs). Darüber hinaus wurde eine Methode zur Analyse von 23 Verbindungen entwickelt, die in Sprengstoffen enthalten sind, die in der Vergangenheit in die Ostsee verklappt wurden, wobei ein anderes Verfahren zur Probenvorbereitung verwendet wurde. Eine spezifische Ziel-Screeningmethode, die dieselbe Probenvorbereitung verwendet, wurde auch für 13 neue phosphororganische Flammschutzmittel (OPFR) und zwei Dechloran-plus-Verbindungen angewandt.Das Verdachtsscreening von 65.690 umweltrelevanten Substanzen aus der NORMAN-Stoffdatenbank wurde an allen HRMSRohchromatogrammen durchgeführt. Die Chromatogramme wurden auch in die NORMAN Digital Sample Freezing Platform (DSFP) hochgeladen und stehen somit für das retrospektive Screening von noch mehr Verbindungen zur Verfügung, sobald die Informationen für deren Screening verfügbar sind...

ERA-MIN 2: RedOxRec - Reduktion/Oxidation Recycling, Teilvorhaben 2: Optimierung des Edelmetall-Leachings

Charakterisierung der mit Natriumpyrophosphat löslichen organischen Bodensusbstanz mittels FT-IR

Zusammensetzung und Menge der organischen Bodensubstanz (OBS) werden durch die Landnutzungsform beeinflußt. Die OBS läßt sich nach ihrer Abbaubarkeit und nach ihrer Löslichkeit in verschiedene Pools einteilen. So kann die wasserlösliche organische Bodensubstanz (DOM) als Maßzahl für die abbaubare OBS herangezogen werden. Mit Natriumpyrophosphat-Lösung als Extraktionsmittel läßt sich ein weit größerer Anteil der OBS erfassen, da der stabilisierende Bindungsfaktor zwischen OBS und Bodenmineralen entfernt wird. Extrahiert man zuerst mit Wasser und anschließend mit Natriumpyrophosphat-Lösung, erhält man im letzten Schritt den schwer abbaubaren OBS-Anteil. Über die funktionelle Zusammensetzung der organischen Substanz dieser Pools und deren Abhängigkeit von Landnutzungsformen ist relativ wenig bekannt. Ziel der geplanten Untersuchung ist es, den Pool der löslichen abbaubaren und schwer abbaubaren OBS zu quantifizieren und deren funktionelle Zusammensetzung mittels FT-IR Spektroskopie zu erfassen. Die so gewonnenen Daten sollen der Validierung von Soil Organic Matter Turnover modellen (z.B. Roth 23.6) dienen und die im Modell berechneten Pools um einen qualitativen Term ergänzen. In Zusammenarbeit mit anderen Arbeitsgruppen sollen im DFG-Schwerpunktprogramm 1090: ;Böden als Quelle und Senke für CO2 die Pools der löslichen abbaubaren und schwer schwer löslichen, schwer abbaubaren organischen Bodensubstanz (OBS) quantifiziert, die funktionelle Zusammensetzung dieser Pools mittels FT-IR Spektroskopie erfasst und Abbaubarkeit der erhaltenen Extrakte überprüft werden, um Mechanismen, die zur Stabilisierung der OBS führen, aufzuklären.

BIOVENTING zur in-situ Sanierung von Mineralöl-kontaminierten Standorten

BIOVENTING ist ein sehr kosteneffizientes Verfahren zur Entfernung von schwerflüchtigen organischen Schadstoffen (Diesel, Heizöle, Schmieröle, etc.) aus der ungesättigten Bodenzone. Durch Sauerstoffanreicherung im Untergrund (Absaugung der Bodenluft, Eintrag von Umgebungsluft) wird der mikrobielle Schadstoffabbau angeregt. Durch Mineralisation werden die abbau- und verfügbaren Kontaminanten (Kohlenwasserstoffe) aus dem Boden entfernt. Im Rahmen dieses Projektes wurden Methoden zur Ermittlung der Einsatzgrenzen dieses in-situ Verfahrens entwickelt. Neben einer Überprüfung der physikalisch-chemischen Voraussetzungen (Durchlässigkeit, Wassersättigung, Alkalinität, Nährstoffgehalt) werden am Standort Untersuchungen (Bodengasanalysen, in-situ Repirationstests) zur Bestimmung der biologischen Abbaubarkeit der Kontaminanten durchgeführt. Anhand dieser Methoden kann überprüft werden, ob ein kontaminierter Standort durch Einsatz des BIOVENTING-Verfahrens sanieren werden kann.

Schwerpunktprogramm (SPP) 1689: Climate Engineering: Risiken, Herausforderungen, Möglichkeiten?, Climate Engineering on Land: Potentials and side-effects of afforestation and biomass plantations as instruments for carbon extraction (CE-LAND WP5) Land use trade-offs in terrestrial CDR pathways

The objective of this project is to provide a comprehensive quantification of the potentials and consequences of large-scale terrestrial Carbon Dioxide removal (CDR) as a strategy for climate engineering (CE). Using two state-of-the-art modeling systems, MPI-ESM and LPJmL, we will quantify Carbon sequestration potentials of four different forest CDR types: semi-natural forest, managed forest and biomass plantation of woody and herbaceous plant types, for various biomass utilization pathways such as conventional wood usage or CCS. The analysis includes associated changes in ecosystem processes and surface properties and their effects on, and feedbacks to, local to global climate. We will additionally analyze (unintended) consequences of these different terrestrial CDR strategies vis-à-vis other prospective use of land and water resources, particularly for food production and ecosystem conservation, and identify regions where afforestation is judged to be sustainable from this broader perspective. WP 5 - Land use trade-offs in terrestrial CDR pathways.

Schwerpunktprogramm (SPP) 1689: Climate Engineering: Risiken, Herausforderungen, Möglichkeiten?, Climate Engineering on Land: Potentials and side-effects of afforestation and biomass plantations as instruments for carbon extraction (CE-LAND WP4 ) Direct and indirect biogeochemical consequences of terrestrial CDR

The objective of this project is to provide a comprehensive quantification of the potentials and consequences of large-scale terrestrial Carbon Dioxide removal (CDR) as a strategy for climate engineering (CE). Using two state-of-the-art modeling systems, MPI-ESM and LPJmL, we will quantify Carbon sequestration potentials of four different forest CDR types: semi-natural forest, managed forest and biomass plantation of woody and herbaceous plant types, for various biomass utilization pathways such as conventional wood usage or CCS. The analysis includes associated changes in ecosystem processes and surface properties and their effects on, and feedbacks to, local to global climate. We will additionally analyze (unintended) consequences of these different terrestrial CDR strategies vis-à-vis other prospective use of land and water resources, particularly for food production and ecosystem conservation, and identify regions where afforestation is judged to be sustainable from this broader perspective. WP 4 - Direct and indirect biogeochemical consequences of terrestrial CDR.

Schwerpunkt der deutschen Partner: Effektive Architekturen und Leistungswandler für Solarstromgeneratoren (PV/CPV) - ERG: Energy for a green society: from sustainable harvesting to smart distribution. Equipment, materials, design solutions and their applications

The research, development and demonstration activities planned for the ERG project focus on the solar energy supply chain, starting form solar cells and proceeding along with innovative energy extraction (harvesting) techniques, high efficiency power conversion and finally managing the energy distribution inside a smart grid, with the target of different classes of applications, from house to small area, as well as application specific 'local grid' (healthcare, automotive, etc). By considering the full solar energy supply chain, we expect to produce relevant improvements of the industrial state-of-the-art in the efficiency of solar cells, in the optimization of energy generated by photovoltaic systems, in the loss reduction of power converters and, finally, in energy management strategy. At the initial chain-link of the energy value chain, the project aims to design and develop a set of innovative solar cells. In particular we primarily target the development of ultra-thin (20 micron) Si wafer PV cells, Si hetero-junction cells (tandem/multi-junction and hetero-junction contacts), novel architectures (e.g., back-contact), novel materials (for Si hetero-junctions, ARC, and passivation dielectrics), novel approaches for screen printing and laser processing, with focus to the case of back-contact cells. As a promising low-cost alternative to Si, ERG will pursue the goal of totally printable dye-sensitized-solar-cells (DSSC). This will include (a) printable electrolyte (to replace liquid electrolyte), (b) advanced TiO2 electrode, and (c) counter electrode (to meet high performance DSSC applications). The overall objective is to demonstrate DSSC products for commercial applications. The next downward chain-link addressed by the project deals with optimization of the energy generated by photovoltaic systems by focusing on power management electronics for silicon cell panels and on micro electromechanical systems for Concentrated Photovoltaic cells (CPV). The complete supply chains will be considered for optimum energy exploitation by Maximum Power Point Tracking (MPPT) and power conversion on module / segment levels for PV and also CPV solar generators. The architecture study will elaborate different profiles of end-users, including direct grid connection, energy storage option and E-mobility support. As the final chain-link is concerned, the project will develop behavioural models for the individual components of the 'Smart Grid'. This allows the development of optimal energy dispatching and battery charging algorithms. These algorithms will obtain their input from sensors distributed over the network, with typically, but not exclusive, a wireless communication infrastructure. A full set of demonstrators, including innovative PV cells, novel conversion systems for PV and CPV inverters, and network demonstrators based on a household application and an industrial application will complete the project deliverables.

Application of biofiltration as a promising pre-treatment method to enhance the sustainability of low-pressure membrane operations

Membranes are finding increasing application in drinking water treatment. The most significant issue facing membrane operation is fouling, leading to a reduction in throughput and/or increase of the transmembrane pressure. Its control and prevention result in high manpower requirements as well as in increased electrical power consumption and increases in the use of chemicals for cleaning. The need to maintain a high permeate flux is one of the major cost factors - capital as well as operating costs - associated with membrane systems. Although biological filtration processes have long been used in drinking water treatment, their successful application as a pre-treatment to reduce membrane fouling is quite recent. The overall goal of the proposed research is to determine optimal operation and backwash procedure for this promising technology to be applied as pre-treatment to enhance the sustainability of low-pressure membrane operations. In addition, biofiltration applied as a 'green' membrane pre-treatment is to be optimized under different seasonal conditions in Lake Ontario (feed quality, temperature, and flow pattern) and compared with a conventional membrane pre-treatment method (coagulation/flocculation). For this purpose, full-scale biologically active carbon contactors (BACCs) will be operated and optimized, so that the applicability can already be proved in an experimental phase.

Interaction of Aerosols with Clouds and Radiation

High uncertainties in future climate predictions arise from insufficient knowledge of the interaction of clouds with visible (solar) and infrared (terrestrial) radiation. The optical properties and lifetime of clouds are strongly influenced by the ability of atmospheric aerosol particles to act as cloud condensation nuclei (CCN) or ice nuclei (IN). This so-called indirect aerosol effect has been recognized as one of the greatest source of uncertainty in assessing human impact on climate. Up to now, the climate relevant properties of clouds and their formation processes are still poorly understood, particularly those of mixed-phase clouds where supercooled cloud droplets and ice crystals coexist. Previous research has found that the cloud radiative properties strongly depend on the cloud ice mass fraction, which is influenced by the abundance of IN. Increased IN concentrations are also thought to enhance precipitation, thus causing a decrease in cloud lifetime and cloud cover, resulting in a warming of the atmosphere. Burning questions that we will address are: Which aerosol particles act as IN in our atmosphere ? By which detailed mechanisms do atmospheric aerosols contribute to the formation of ice ? To answer these questions, one major goal of this project is to develop a new inlet for the measurement of cloud droplets and ice crystals. This inlet will also allow the extraction of small ice particles in mixed-phase clouds for the physico-chemical characterization of tropospheric IN. The inlet will represent a novel tool for the in-situ investigation of clouds and will deliver information that is not available by means of any other existing inlet. Measurements will be performed at the Jungfraujoch, one of the world's most prominent high Alpine research stations located at 3580 m altitude in the middle of Switzerland. This unique location offers the possibility to perform these studies in mixed-phase clouds that are representative for the current European background. The proposed research will be performed in a collaborative effort of the Laboratory of Atmospheric Chemistry of the Paul Scherrer Institut (aerosol/cloud research) and the Institute for Meteorology and Climate Research at the Karlsruhe Institute of Technology (cloud microphysics and optics).

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