TY - JOUR A1 - López-Tarazón, José Andrés A1 - Lopez, Pilar A1 - Lobera, Gemma A1 - Batalla Villanueva, Ramon J. T1 - Suspended sediment, carbon and nitrogen transport in a regulated Pyrenean river JF - The science of the total environment : an international journal for scientific research into the environment and its relationship with man N2 - Regulation alters the characteristics of riversty transforming parts of them into lakes, affecting their hydrology and also the physical, chemical, and biological characteristics and dynamics. Reservoirs have proven to be very effective retaining particulate materials, thereby avoiding the downstream transport of suspended sediment and the chemical substances associated with it (e.g. Carbon, C or Nitrogen, N). The study of fluvial transport of C and N is of great interest since river load represents a major link to the global C and N cycles. Moreover, reservoirs are the most important sinks for organic carbon among inland waters and have a potential significance as nitrogen sinks. In this respect, this paper investigates the effects of a Pyrenean reservoir on the runoff, suspended sediment, C and N derived from the highly active Esera and Isabena rivets. Key findings indicate that the reservoir causes a considerable impact on the Esera-Isabena river fluxes, reducing them dramatically as almost all the inputs are retained within the reservoir. Despite the very dry study year (2011-2012), it can be calculated that almost 300,000 t of suspended sediment were deposited into the Barasona Reservoir, from which more than 16,000 were C (i.e. 2200 t as organic C) and 222 t were N. These values may not be seen as remarkable in a wider global context but, assuming that around 30 hm(3) of sediment are currently stored in the reservoir, figures would increase up to ca. 2.6 x 10(6) t of C (i.e. 360,000 t of organic C) and 35,000 t of N. Nevertheless, these values are indicative and should be treated with caution as there is incomplete understanding of all the processes which affect C and N. Further investigation to establish a more complete picture of C and N yields and budgets by monitoring the different processes involved is essential. (C) 2015 Elsevier B.V. All rights reserved. KW - Suspended sediment KW - Carbon KW - Nitrogen KW - Temporal dynamics KW - Barasona Reservoir KW - River Esera KW - Ebro basin Y1 - 2016 U6 - https://doi.org/10.1016/j.scitotenv.2015.06.132 SN - 0048-9697 SN - 1879-1026 VL - 540 SP - 133 EP - 143 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Schmidt, Martin A1 - Lischeid, Gunnar A1 - Nendel, Claas T1 - Microclimate and matter dynamics in transition zones of forest to arable land JF - Agricultural and forest meteorology N2 - Human-driven fragmentation of landscapes leads to the formation of transition zones between ecosystems that are characterised by fluxes of matter, energy and information. These transition zones may offer rather inhospitable habitats that could jeopardise biodiversity. On the other hand, transition zones are also reported to be hotspots for biodiversity and even evolutionary processes. The general mechanisms and influence of processes in transition zones are poorly understood. Although heterogeneity and diversity of land use of fragments and the transition zones between them play an important role, most studies only refer to forested transition zones. Often, only an extrapolation of measurements in the different fragments themselves is reported to determine gradients in transition zones. This paper contributes to a quantitative understanding of agricultural landscapes beyond individual ecotopes, and towards connected ecosystem mosaics that may be beneficial for the provision of ecosystem services. KW - Edge effects KW - Environmental gradients KW - Fragmentation KW - Ecosystem services KW - Carbon KW - Nitrogen Y1 - 2019 U6 - https://doi.org/10.1016/j.agrformet.2019.01.001 SN - 0168-1923 SN - 1873-2240 VL - 268 SP - 1 EP - 10 PB - Elsevier CY - Amsterdam ER - TY - INPR A1 - Baur, Heiner A1 - Hoffmann, Jan A1 - Reichmuth, Anne A1 - Müller, Steffen A1 - Mayer, Frank T1 - Influence of carbon fiber foot orthoses on plantar pressure distribution in cycling T2 - Sportverletzung, Sportschaden : Grundlagen, Prävention, Rehabilitation N2 - Background: Several equipment interventions like optimizing seat position or optimizing shoe/insole/pedal interface are suggested to reduce overuse injury in cycling. Data analyzing clinical or biomechanical effects of those interventions is sparse. Foot orthoses out of carbon fiber are one possibility to alter the interface between foot and pedal. The aim of this study was therefore to analyze plantar pressure distribution in carbon fiber foot orthoses in comparison to standard insoles of commercially available cycling shoes. Materials and Methods: 11 pain-free triathletes (Age: 29 +/- 9, 1.77 +/- 0.04 m, 68 5 kg) were tested on a cycle ergometer at 60 and 90 rotations per minute (rpm) at workloads of 200 and 300 Watts. Subjects wore in randomized order a cycling shoe with its standard insole (control condition CO) or the shoe with carbon fiber foot orthoses (Condition CA). Mean peak pressure out of 30 movement cycles were extracted for the total foot and specific foot regions (rear, mid, fore foot (medial, central, lateral) and toe region). Three-factor ANOVAs (factor foot orthoses, rpm, workload) for repeated measures (alpha = 0.05) were used to analyze the main question of a foot orthoses effect on peak in-shoe plantar pressure. Results: Peak pressures in the total foot were in a range of 70-75 kPa for 200 Watts (W) (300 W: 85-110 kPa). The carbon fiber foot orthoses reduced peak pressures by -4,1% compared to the standard insole (p = 0,10). In the foot regions rear(-16,6%, p<0.001), mid (-20,0%, p<0.001) and fore foot (-5.9%, p < 0.03)CA reduced peak pressure compared to CO. In the toe region, peak pressure was higher in CA (+16,2%) compared to CO (p<0,001). The lateral fore foot showed higher peak pressures in CA (+34%) and CO (+59%) compared to medial and central fore foot. Conclusion: Carbon fiber can serve as a suitable material for foot orthoses manufacturing in cycling. Plantar pressures do not increase due to the stiffness of the carbon. Individual customization may have the potential to reduce peak pressure in certain foot areas. KW - Carbon KW - Cycling KW - Foot orthoses KW - In-shoe measurement KW - Plantar Pressure Distribution Y1 - 2012 SN - 0932-0555 VL - 26 IS - 1 SP - 12 EP - 17 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Streck, Charlotte T1 - How voluntary carbon markets can drive climate ambition JF - Journal of energy & natural resources law : the journal of the Section on Energy and Natural Resources Law of the International Bar Association N2 - Over the last three years, corporate interest in voluntary carbon markets has almost tripled, and this trend has seemed to resist the COVID-19 economic fallout. If managed well, this market has the potential to become a very significant driver of mitigation action, in particular in developing countries, which supply the majority of voluntary carbon offsets. Robust standards and rules can overcome concerns that voluntary carbon markets could lead to company greenwashing and undermine the goals of the Paris Agreement. On the contrary, voluntary corporate investments can encourage more ambitious government climate action, and encourage governments to make more ambitious pledges under the Paris Agreement. Multisectoral mitigation partnerships can ensure the complementarity of public and private action and support policy alignment and investments in priority sectors and regions. KW - Climate Policy KW - Paris Agreement KW - Corporate Climate Action KW - Carbon KW - Markets KW - public-private partnerships Y1 - 2021 U6 - https://doi.org/10.1080/02646811.2021.1881275 SN - 0264-6811 SN - 2376-4538 VL - 39 IS - 3 SP - 367 EP - 374 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Schälicke, Svenja A1 - Teubner, Johannes A1 - Martin-Creuzburg, Dominik A1 - Wacker, Alexander T1 - Fitness response variation within and among consumer species can be co-mediated by food quantity and biochemical quality JF - Scientific Reports N2 - In natural heterogeneous environments, the fitness of animals is strongly influenced by the availability and composition of food. Food quantity and biochemical quality constraints may affect individual traits of consumers differently, mediating fitness response variation within and among species. Using a multifactorial experimental approach, we assessed population growth rate, fecundity, and survival of six strains of the two closely related freshwater rotifer species Brachionus calyciflorus sensu stricto and Brachionus fernandoi. Therefore, rotifers fed low and high concentrations of three algal species differing in their biochemical food quality. Additionally, we explored the potential of a single limiting biochemical nutrient to mediate variations in population growth response. Therefore, rotifers fed a sterol-free alga, which we supplemented with cholesterol-containing liposomes. Co-limitation by food quantity and biochemical food quality resulted in differences in population growth rates among strains, but not between species, although effects on fecundity and survival differed between species. The effect of cholesterol supplementation on population growth was strain-specific but not species-specific. We show that fitness response variations within and among species can be mediated by biochemical food quality. Dietary constraints thus may act as evolutionary drivers on physiological traits of consumers, which may have strong implications for various ecological interactions. KW - Polyunsaturated Fatty-Acids KW - Life-History Consequences KW - 2 Different Strains KW - Population-Growth KW - Resource Competition KW - Body-Size KW - Egg Size KW - Rotifier KW - Limitation KW - Carbon Y1 - 2019 U6 - https://doi.org/10.1038/s41598-019-52538-2 SN - 2045-2322 VL - 9 PB - Macmillan Publishers Limited CY - London ER - TY - THES A1 - Lian, Tingting T1 - Efficient activation of peroxymonosulfate by carbon-based catalysts for water purification N2 - The increasing global population has led to a growing demand for cost-effective and eco-friendly methods of water purification. This demand has reached a peak due to the increasing presence of impurities and pollutants in water and a growing awareness of waterborne diseases. Advanced oxidation processes (AOPs) are effective methods to address these challenges, due to the generation of highly reactive radicals, such as sulfate radical (SO4•-), hydroxyl radical (•OH), and/or superoxide radical (•O2-) in oxidation reactions. Relative to conventional hydrogen peroxide (H2O2)-based AOPs for wastewater treatment, the persulfate-related AOPs are receiving increasing attention over the past decades, due to their stronger oxidizing capability and a wider pH working window. Further deployment of the seemingly plausible technology as an alternative for the well-established one in industry, however, necessitates a careful evaluation of compounding factors, such as water matrix effects, toxicological consequences, costs, and engineering challenges, etc. To this end, rational design of efficient and environmentally friendly catalysts constitutes an indispensable pathway to advance persulfate activation efficacy and to elucidate the mechanisms in AOPs, the combined endeavors are expected to provide insightful understanding and guidelines for future studies in wastewater treatment. A dozens of transition metal-based catalysts have been developed for persulfate-related AOPs, while the undesirable metal leaching and poor stability in acidic conditions have been identified as major obstacles. Comparatively, the carbonaceous materials are emerging as alternative candidates, which are characterized by metal-free nature, wide availability, and exceptional resistance to acid and alkali, as well as tunable physicochemical and electronic properties, the combined merits make them an attractive option to overcome the aforementioned limitations in metal-based catalytic systems. This dissertation aims at developing novel carbonaceous materials to boost the activity in peroxymonosulfate (PMS) activation processes. Functionalized carbon materials with metal particles or heteroatoms were constructed and further evaluated in terms of their ability to activate PMS for AOPs. The main contents of this thesis are summarized as follows: (1) Iron oxide-loaded biochar: improving stability and alleviating metal leakage Metal leaching constitutes one of the main drawbacks in using transition metals as PMS activators, which is accompanied by the generation of metal-containing sludge, potentially leading to secondary pollution. Meanwhile, the metal nanoparticles are prone to aggregate, causing rapid decay of catalytic performance. The use of carbons as supports for transition metals could mitigate these deficiencies, because the interaction between metals and carbons could in turn disperse and stabilize metal nanoparticles, thus suppressing the metal leaching. In this work, the environmentally benign lignin with its abundant phenolic groups, which is well known to serve as carbon source with high yields and flexibility, was utilized to load Fe ions. The facile low-temperature pre-treatment pyrolytic strategy was employed to construct a green catalyst with iron oxides embedded in Kraft-lignin-derived biochar (termed as γ-Fe2O3@KC). The γ-Fe2O3@KC was capable of activating PMS to generate stable non-radical species (1O2 and Fe (V)=O) and to enhance electron transfer efficiency. A surface-bound reactive complex (catalyst-PMS*) was identified by electrochemical characterizations and discussed with primary surface-bound radical pairs to explain the contradictions between quenching and EPR detection results. The system also showed encouraging reusability for at least 5 times and high stability at pH 3-9. The low concentration of iron in γ-Fe2O3@KC/PMS system implied that the carbon scaffold of biochar substantially alleviated metal leakage. (2) MOF-derived nanocarbon: new carbon crystals Traditional carbon materials are of rather moderate performance in activation PMS, due to the poor electron transfer capacity within the amorphous structure and limited active sites for PMS adsorption. Herein, we established crystalline nanocarbon materials via a simple NaCl-templated strategy using the monoclinic zeolitic imidazolate framework-8 (ZIF-8) sealed with NaCl crystals as the precursors. Specifically, NaCl captured dual advantages in serving as structure-directing agent during hydrolysis and protective salt reactor to facilitate phase transformation during carbonization. The structure-directing agent NaCl provided a protective and confined space for the evolution of MOF upon carbonization, which led to high doping amounts of nitrogen (N) and oxygen elements (O) in carbon framework (N: 14.16 wt%, O: 9.6 wt%) after calcination at a high temperature of 950 oC. We found that N-O co-doping can activate the chemically inert carbon network and the nearby sp2-hybridized carbon atoms served as active sites for adsorption and activation. Besides, the highly crystallized structure with well-established carbon channels around activated carbon atoms could significantly accelerate electron transfer process after initial adsorption of PMS. As such, this crystalline nanocarbon exhibited excellent catalytic kinetics for various pollutants. (3) MOF-derived 2D carbon layers: enhanced mass/electron transfer The two-dimensional (2D) configuration of carbon-based nanosheets with inherent nanochannels and abundant active sites residing on the layer edges or in between the layers, allowed the accessible interaction and close contact between the substrates and reactants, as well as the dramatically improved electron- and mass-transfer kinetics. In this regard, we developed dual-templating strategy to afford 2D assembly of the crystalline carbons, which found efficiency in reinforcing the interactions between the catalyst surface and foreign pollutants. Specifically, we found that the ice crystals and NaCl promoted the evolution of MOF in a 2D fashion during the freezing casting stage, while the later further allowed the formation of a graphitic surface at high calcination temperature, by virtue of the templating effect of molten salt. Due to the highly retained co-doping amounts, N and O heteroatoms created abundant active sites for PMS activation, the 2D configuration of carbon-based nanosheets enable efficient interaction of PMS and pollutants on the surface, which further boosted the kinetics of degradation. KW - Carbon KW - Water treatment KW - PMS activation Y1 - 2023 ER - TY - JOUR A1 - Reverey, Florian A1 - Ganzert, Lars A1 - Lischeid, Gunnar A1 - Ulrich, Andreas A1 - Premke, Katrin A1 - Grossart, Hans-Peter T1 - Dry-wet cycles of kettle hole sediments leave a microbial and biogeochemical legacy JF - The science of the total environment : an international journal for scientific research into the environment and its relationship with man N2 - Understanding interrelations between an environment's hydrological past and its current biogeochemistry is necessary for the assessment of biogeochemical and microbial responses to changing hydrological conditions. The question how previous dry-wet events determine the contemporary microbial and biogeochemical state is addressed in this study. Therefore, sediments exposed to the atmosphere of areas with a different hydrological past within one kettle hole, i.e. (1) the predominantly inundated pond center, (2) the pond margin frequently desiccated for longer periods and (3) an intermediate zone, were incubated with the same rewetting treatment. Physicochemical and textural characteristics were related to structural microbial parameters regarding carbon and nitrogen turnover, i.e. abundance of bacteria and fungi, denitrifiers (targeted by the nirK und nirS functional genes) and nitrate ammonifiers (targeted by the nrfA functional gene). Our study reveals that, in combination with varying sediment texture, the hydrological history creates distinct microbial habitats with defined boundary conditions within the kettle hole, mainly driven by redox conditions, pH and organic matter (OM) composition. OM mineralization, as indicated by CO2-outgassing, was most efficient in exposed sediments with a less stable hydrological past. The potential for nitrogen retention via nitrate ammonification was highest in the hydrologically rather stable pond center, counteracting nitrogen loss due to denitrification. Therefore, the degree of hydrological stability is an important factor leaving a microbial and biogeochemical legacy, which determines carbon and nitrogen losses from small lentic freshwater systems in the long term run. KW - Desiccation KW - DNRA KW - Denitrifiers KW - Organic matter mineralization KW - Carbon KW - Nitrogen Y1 - 2018 U6 - https://doi.org/10.1016/j.scitotenv.2018.01.220 SN - 0048-9697 SN - 1879-1026 VL - 627 SP - 985 EP - 996 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Heslop, J. K. A1 - Anthony, K. M. Walter A1 - Grosse, Guido A1 - Liebner, Susanne A1 - Winkel, Matthias T1 - Century-scale time since permafrost thaw affects temperature sensitivity of net methane production in thermokarst-lake and talik sediments JF - The science of the total environment : an international journal for scientific research into the environment and its relationship with man N2 - Permafrost thaw subjects previously frozen soil organic carbon (SOC) to microbial degradation to the greenhouse gases carbon dioxide (CO2) and methane (CH4). Emission of these gases constitutes a positive feedback to climate warming. Among numerous uncertainties in estimating the strength of this permafrost carbon feedback (PCF), two are: (i) how mineralization of permafrost SOC thawed in saturated anaerobic conditions responds to changes in temperature and (ii) how microbial communities and temperature sensitivities change over time since thaw. To address these uncertainties, we utilized a thermokarst-lake sediment core as a natural chronosequence where SOC thawed and incubated in situ under saturated anaerobic conditions for up to 400 years following permafrost thaw. Initial microbial communities were characterized, and sediments were anaerobically incubated in the lab at four temperatures (0 °C, 3 °C, 10 °C, and 25 °C) bracketing those observed in the lake's talik. Net CH4 production in freshly-thawed sediments near the downward-expanding thaw boundary at the base of the talik were most sensitive to warming at the lower incubation temperatures (0 °C to 3 °C), while the overlying sediments which had been thawed for centuries had initial low abundant methanogenic communities (< 0.02%) and did not experience statistically significant increases in net CH4 production potentials until higher incubation temperatures (10 °C to 25 °C). We propose these observed differences in temperature sensitivities are due to differences in SOM quality and functional microbial community composition that evolve over time; however further research is necessary to better constrain the roles of these factors in determining temperature controls on anaerobic C mineralization. KW - Carbon KW - Lake sediments KW - Methane KW - Permafrost KW - Talik KW - Temperature sensitivity Y1 - 2019 U6 - https://doi.org/10.1016/j.scitotenv.2019.06.402 SN - 0048-9697 SN - 1879-1026 VL - 691 SP - 124 EP - 134 PB - Elsevier CY - Amsterdam ER -