seminar umwelting. papervorschläge hs 2015nasa douglas dc-8 (tail no. n817na) cfm56-2-c1 engines...

Seminar Umwelting. Papervorschläge HS 2015

1) Title Global, regional and local health impacts of civil aviation emissions Author(s) Steve H L Yim, Gideon L Lee, In Hwan Lee, Florian Allroggen, Akshay

Ashok, Fabio Caiazzo, Sebastian D Eastham, Robert Malina and Steven R H Barrett

Year 2015 Journal Environmental Research Letters Link doi:10.1088/1748-9326/10/3/034001

Abstract Aviation emissions impact surface air quality at multiple scales—from near-airport pollution peaks associated with airport landing and take off (LTO) emissions, to intercontinental pollution attributable to aircraft cruise emissions. Previous studies have quantified aviation's air quality impacts around a specific airport, in a specific region, or at the global scale. However, no study has assessed the air quality and human health impacts of aviation, capturing effects on all aforementioned scales. This study uses a multi-scale modeling approach to quantify and monetize the air quality impact of civil aviation emissions, approximating effects of aircraft plume dynamics-related local dispersion (~1 km), near-airport dispersion (~10 km), regional (~1000 km) and global (~10 000 km) scale chemistry and transport. We use concentration-response functions to estimate premature deaths due to population exposure to aviation-attributable PM2.5 and ozone, finding that aviation emissions cause ~16 000 (90% CI: 8300–24 000) premature deaths per year. Of these, LTO emissions contribute a quarter. Our estimate shows that premature deaths due to long-term exposure to aviation-attributable PM2.5 and O3 lead to costs of ~$21 bn per year. We compare these costs to other societal costs of aviation and find that they are on the same order of magnitude as global aviation-attributable climate costs, and one order of magnitude larger than aviation-attributable accident and noise costs.

Verantwortlicher Prof: J.Wang

2) Title Does e-cigarette consumption cause passive vaping? Author(s) T. Schripp, D. Markewitz, E. Uhde andT. Salthammer Year 2012 Journal Indoor Air Link http://onlinelibrary.wiley.com/doi/10.1111/j.1600-

0668.2012.00792.x/abstract

Abstract Electronic cigarette consumption (‘vaping’) is marketed as an alternative to conventional tobacco smoking. Technically, a mixture of chemicals containing carrier liquids, flavors, and optionally nicotine is vaporized and inhaled. The present study aims at the determination of the release of volatile organic compounds (VOC) and (ultra)fine particles (FP/UFP) from an e-cigarette under near-to-real-use conditions in an 8-m3 emission test chamber. Furthermore, the inhaled mixture is analyzed in small chambers. An increase in FP/UFP and VOC could be determined after the use of the e-cigarette. Prominent components in the gas-phase are 1,2-propanediol, 1,2,3-propanetriol, diacetin, flavorings, and traces of nicotine. As a consequence, ‘passive vaping’ must be expected from the consumption of e-cigarettes. Furthermore, the inhaled aerosol undergoes changes in the human lung that is assumed to be attributed to deposition and evaporation.


http://dx.doi.org/10.1088/1748-9326/10/3/034001http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0668.2012.00792.x/abstracthttp://onlinelibrary.wiley.com/doi/10.1111/j.1600-0668.2012.00792.x/abstract


3) Title Influence of Jet Fuel Composition on Aircraft Engine Emissions: A Synthesis of Aerosol Emissions Data from the NASA APEX, AAFEX, and ACCESS Missions

Author(s) Moore RH, Shook M, Beyersdorf AJ, Corr C, Herndon SC, Knighton, W. Berk, Miake-Lye R, Thornhill, K. Lee, Winstead E, Yu Z, Ziemba LD, Anderson BE

Year 2015 Journal Energy Fuels Link http://pubs.acs.org/doi/abs/10.1021/ef502618w

Abstract We statistically analyze the impact of jet fuel properties on aerosols emitted by the NASA Douglas DC-8 (Tail No. N817NA) CFM56-2-C1 engines burning 15 different aviation fuels. Data were collected for this single engine type during four different, comprehensive ground tests conducted over the past decade, which allow us to clearly link changes in aerosol emissions to fuel compositional changes. It is found that the fuel aromatic and sulfur content most affect the volatile aerosol fraction, which dominates the variability (but not necessarily the magnitude) of the number and volume emissions indices (EIs) over all engine powers. Meanwhile, the naphthalenic content of the fuel determines the magnitude of the nonvolatile number and volume EI as well as the black carbon mass EI. Linear regression coefficients are reported for each aerosol EI in terms of these properties, engine fuel flow rate, and ambient temperature and show that reducing both fuel sulfur content and naphthalenes to near-zero levels would result in roughly a 10-fold decrease in aerosol number emitted per kilogram of fuel burned. This work informs future efforts to model aircraft emissions changes as the aviation fleet gradually begins to transition toward low-aromatic, low-sulfur alternative jet fuels from biobased or Fischer–Tropsch production pathways.


4) Title Principles for scaling of distributed direct potable water reuse systems: A modeling study

Author(s) Tianjiao Guo, James D. Englehardt Year 2015 Journal Water Research Link http://dx.doi.org/10.1016/j.watres.2015.02.033

Abstract Scaling of direct potable water reuse (DPR) systems involves tradeoffs of treatment facility economy-of-scale, versus cost and energy of conveyance including energy for upgradient distribution of treated water, and retention of wastewater thermal energy. In this study, a generalized model of the cost of DPR as a function of treatment plant scale, assuming futuristic, optimized conveyance networks, was constructed for purposes of developing design principles. Fractal landscapes representing flat, hilly, and mountainous topographies were simulated, with urban, suburban, and rural housing distributions placed by modified preferential growth algorithm. Treatment plants were allocated by agglomerative hierarchical clustering, networked to buildings by minimum spanning tree. Simulations assume advanced oxidation-based DPR system design, with 20-year design life and capability to mineralize chemical oxygen demand below normal detection limits, allowing implementation in regions where disposal of concentrate containing hormones and antiscalants is not practical. Results indicate that total DPR capital and O&M costs in rural areas, where systems that return nutrients to the land may be more appropriate, are high. However, costs in urban/suburban areas are competitive with current water/wastewater service costs at scales of ca. one plant per 10,000 residences. This size is relatively small, and costs do not increase significantly until plant service areas fall below 100 to 1000 homes. Based on these results, distributed DPR systems are recommended for consideration for urban/suburban water and wastewater system capacity expansion projects

Verantwortlicher Pof: M. Maurer

http://pubs.acs.org/doi/abs/10.1021/ef502618whttp://dx.doi.org/10.1016/j.watres.2015.02.033


5) Title Challenges of surveying wastewater drug loads of small populations and generalizable aspects on optimizing monitoring design

Author(s) Christoph Ort, Jonas Maria Eppler, Andreas Scheidegger, Jörg Rieckermann, Martina Kinzig und Fritz Sörgel

Year 2014 Journal Addiction Link http://onlinelibrary.wiley.com/doi/10.1111/add.12405/epdf

Abstract Aims Quantifying illicit drug loads through wastewater analysis (WWA) is an alternative approach to estimating population drug use. This study investigated the variability of daily drug loads in wastewater and their relationships to environmental factors over an extended period to: (i) explore the suitability of WWA in small populations and (ii) optimize the monitoring design for future studies. Design, Setting, Participants Daily wastewater samples (n = 1369 consecutive days) from a German village with approximately 7160 inhabitants. Measurements Samples were analysed for cocaine and benzoylecgonine with liquid chromatography-tandem mass spectrometry. Time-series analysis was used to explore the effects of weather and other factors on daily cocaine loads. Subsampling was used to assess monitoring design. Findings Cocaine loads [mean = 652 mgCOC/day, standard deviation (SD) = 498 mgCOC/day] increased over the study period, with higher values during winter and spring. Despite high day-to-day variation, loads were significantly higher during weekends [+161 mgCOC/day, 95% confidence interval (CI) = 115–207 mgCOC/day, P


6) Title Quantification of groundwater infiltration and surface water inflows in urban sewer networks based on a multiple model approach

Author(s) Christian Karpf, Peter Krebs Year 2011 Journal Water Research Link http://www.sciencedirect.com/science/article/pii/S0043135411001333

Abstract The management of sewer systems requires information about discharge and variability of typical wastewater sources in urban catchments. Especially the infiltration of groundwater and the inflow of surface water (I/I) are important for making decisions about the rehabilitation and operation of sewer networks. This paper presents a methodology to identify I/I and estimate its quantity. For each flow fraction in sewer networks, an individual model approach is formulated whose parameters are optimised by the method of least squares. This method was applied to estimate the contributions to the wastewater flow in the sewer system of the City of Dresden (Germany), where data availability is good. Absolute flows of I/I and their temporal variations are estimated. Further information on the characteristics of infiltration is gained by clustering and grouping sewer pipes according to the attributes construction year and groundwater influence and relating these resulting classes to infiltration behaviour. Further, it is shown that condition classes based on CCTV-data can be used to estimate the infiltration potential of sewer pipes.

Verantwortlicher Prof: M. Maurer

7) Title Dynamic time warping improves sewer flow monitoring Author(s) D.J. Dürrenmatt , D. Del Giudice, J. Rieckermann Year 2013 Journal Water Research Link http://www.sciencedirect.com/science/article/pii/S0043135413002753

Abstract Successful management and control of wastewater and storm water systems requires accurate sewer flow measurements. Unfortunately, the harsh sewer environment and insufficient flow meter calibration often lead to inaccurate and biased data. In this paper, we improve sewer flow monitoring by creating redundant information on sewer velocity from natural wastewater tracers. Continuous water quality measurements upstream and downstream of a sewer section are used to estimate the travel time based on i) cross-correlation (XCORR) and ii) dynamic time warping (DTW). DTW is a modern data mining technique that warps two measured time series non-linearly in the time domain so that the dissimilarity between the two is minimized. It has not been applied in this context before. From numerical experiments we can show that DTW outperforms XCORR, because it provides more accurate velocity estimates, with an error of about 7% under typical conditions, at a higher temporal resolution. In addition, we can show that pre-processing of the data is important and that tracer reaction in the sewer reach is critical. As dispersion is generally small, the distance between the sensors is less influential if it is known precisely. Considering these findings, we tested the methods on a real-world sewer to check the performance of two different sewer flow meters based on temperature measurements. Here, we were able to detect that one of two flow meters was not performing satisfactorily under a variety of flow conditions. Although theoretical analyses show that XCORR and DTW velocity estimates contain systematic errors due to dispersion and reaction processes, these are usually small and do not limit the applicability of the approach.


http://www.sciencedirect.com/science/article/pii/S0043135411001333http://www.sciencedirect.com/science/article/pii/S0043135413002753


8) Title Effects of nitrite concentration and exposure time on sulfide and methane production in sewer systems

Author(s) Guangming Jiang, Oriol Gutierrez, Keshab Raj Sharma, Zhiguo Yuan Year 2010 Journal Water Research Link http://www.sciencedirect.com/science/article/pii/S0043135410003386

Abstract Nitrite dosing is a promising technology to prevent sulfide and methane formation in sewers, due to the known inhibitory/toxic effect of nitrite on sulfate-reducing bacteria (SRB) and methanogenic Archaea (MA). The dependency of nitrite-induced inhibition on sulfide and methane producing activities of anaerobic sewer biofilms on nitrite levels and exposure time is investigated using a range of nitrite concentrations (40, 80, 120 mg-N/L) and exposure time up to 24 days. The recovery of these activities after the 24-day nitrite dosage was also monitored for more than two months. The inhibition level was found to be dependent on both nitrite concentration and exposure time, with stronger inhibition observed at higher nitrite concentrations and/or longer exposure time. However, the time required for achieving 50% recovery of both sulfate-reducing and methanogenic activities after the cessation of nitrite dosage only marginally depended on nitrite concentration. Model-based analysis of the recovery data showed that the recovery was likely due to the regrowth of SRB and methanogens. The lab studies and mathematical analysis supported the development of an intermittent dosing strategy, which was tested in a 1-km long rising main sewer. The field trial confirmed that intermittent dosing of nitrite can effectively reduce/prevent the formation of both sulfide and methane.


9) Title Planetary boundaries: Guiding human development on a changing planet

Author(s) Steffen, Will et al. Year 2015 Journal Science Link http://www.sciencemag.org/content/347/6223/1259855

Abstract The planetary boundaries framework defines a safe operating space for humanity based on the intrinsic biophysical processes that regulate the stability of the Earth system. Here, we revise and update the planetary boundary framework, with a focus on the underpinning biophysical science, based on targeted input from expert research communities and on more general scientific advances over the past 5 years. Several of the boundaries now have a two-tier approach, reflecting the importance of cross-scale interactions and the regional-level heterogeneity of the processes that underpin the boundaries. Two core boundaries—climate change and biosphere integrity—have been identified, each of which has the potential on its own to drive the Earth system into a new state should they be substantially and persistently transgressed.

Verantwortliche Prof: S. Hellweg

http://www.sciencedirect.com/science/article/pii/S0043135410003386http://www.sciencemag.org/content/347/6223/1259855


10) Title Molecular detection of pathogens in water – The pros and cons of molecular techniques

Author(s) Rosina Girones, Maria Antonia Ferrús, José Luis Alonso, Jesus Rodriguez-Manzano, Byron Calgua, Adriana de Abreu Corrêa, Ayalkibet Hundesa, Anna Carratala, Sílvia Bofill-Mas

Year 2010 Journal Water Research Link http://www.sciencedirect.com/science/article/pii/S0043135410004173

Abstract Pollution of water by sewage and run-off from farms produces a serious public health problem in many countries. Viruses, along with bacteria and protozoa in the intestine or in urine are shed and transported through the sewer system. Even in highly industrialized countries, pathogens, including viruses, are prevalent throughout the environment. Molecular methods are used to monitor viral, bacterial, and protozoan pathogens, and to track pathogen- and source-specific markers in the environment. Molecular techniques, specifically polymerase chain reaction-based methods, provide sensitive, rapid, and quantitative analytical tools with which to study such pathogens, including new or emerging strains. These techniques are used to evaluate the microbiological quality of food and water, and to assess the efficiency of virus removal in drinking and wastewater treatment plants. The range of methods available for the application of molecular techniques has increased, and the costs involved have fallen. These developments have allowed the potential standardization and automation of certain techniques. In some cases they facilitate the identification, genotyping, enumeration, viability assessment, and source-tracking of human and animal contamination. Additionally, recent improvements in detection technologies have allowed the simultaneous detection of multiple targets in a single assay. However, the molecular techniques available today and those under development require further refinement in order to be standardized and applicable to a diversity of matrices. Water disinfection treatments may have an effect on the viability of pathogens and the numbers obtained by molecular techniques may overestimate the quantification of infectious microorganisms. The pros and cons of molecular techniques for the detection and quantification of pathogens in water are discussed.


http://www.sciencedirect.com/science/article/pii/S0043135410004173


11) Title Fate and transformation of silver nanoparticles in urban wastewater systems

Author(s) Ralf Kaegi, Andreas Voegelin, Christoph Ort, Brian Sinnet, Basilius Thalmann, Jasmin Krismer, Harald Hagendorfer, Maline Elumelu, Elisabeth Mueller


Abstract Discharge of silver nanoparticles (Ag-NP) from textiles and cosmetics, todays major application areas for metallic Ag-NP, into wastewater is inevitable. Transformation and removal processes in sewers and wastewater treatment plants (WWTP) will determine the impact of Ag-NP on aquatic and terrestrial environments, via the effluents of the WWTP and via the use of digested sludge as fertilizer. We thus conducted experiments addressing the behavior of Ag-NP in sewers and in WWTP. We spiked Ag-NP to a 5 km long main trunk sewer and collected 40 wastewater samples after 500 m, 2400 m and 5000 m each according to the expected travel times of the Ag-NP. Excellent mass closure of the Ag derived by multiplying the measured Ag concentrations times the volumetric flow rates indicate an efficient transport of the Ag-NP without substantial losses to the sewer biofilm. Ag-NP reacted with raw wastewater in batch experiments were sulfidized to roughly 15% after 5 h reaction time as revealed by X-ray absorption spectroscopy (XAS). However, acid volatile sulfide (AVS) concentrations were substantially higher in the sewer channel (100 μM) compared to the batch experiments (3 μM; still sufficient to sulfidize spiked 2 μM Ag) possibly resulting in a higher degree of sulfidation in the sewer channel. We further investigated the removal efficiency of 10 nm and 100 nm Ag- and gold (Au)-NP coated with citrate or polyvinylpyrrolidone in activated sludge batch experiments. We obtained very high

removal efficiencies (∼99%) irrespective of size and coating for Ag- and Au-NP, the latter confirming that the particle type was of minor importance with respect to the degree of NP removal. We observed a strong size dependence of the sulfidation kinetics. We conclude that Ag-NP discharged to the wastewater stream will become sulfidized to various degrees in the sewer system and are efficiently transported to the WWTP. The sulfidation of the Ag-NP will continue in the WWTP, but primarily depending on the size the Ag-NP, may not be complete. Very high removal efficiencies in the WWTP will divert most of the Ag-NP mass flow to the digester and only a small fraction of the Ag will be released to surface waters.




12) Title Comparison of different uncertainty techniques in urban stormwater quantity and quality modelling

Author(s) Dotto, CBS ; Mannina, G ; Kleidorfer, M ; Vezzaro, L ; Henrichs, M ; Mccarthy, Dt ; Freni, G ; Rauch, W ; Deletic, A


Abstract Urban drainage models are important tools used by both practitioners and scientists in the field of stormwater management. These models are often conceptual and usually require calibration using local datasets. The quantification of the uncertainty associated with the models is a must, although it is rarely practiced. The International Working Group on Data and Models, which works under the IWA/IAHR Joint Committee on Urban Drainage, has been working on the development of a framework for defining and assessing uncertainties in the field of urban drainage modelling. A part of that work is the assessment and comparison of different techniques generally used in the uncertainty assessment of the parameters of water models. This paper compares a number of these techniques: the Generalized Likelihood Uncertainty Estimation (GLUE), the Shuffled Complex Evolution Metropolis algorithm (SCEM-UA), an approach based on a multi-objective auto-calibration (a multialgorithm, genetically adaptive multi-objective method, AMALGAM) and a Bayesian approach based on a simplified Markov Chain Monte Carlo method (implemented in the software MICA). To allow a meaningful comparison among the different uncertainty techniques, common criteria have been set for the likelihood formulation, defining the number of simulations, and the measure of uncertainty bounds. Moreover, all the uncertainty techniques were implemented for the same case study, in which the same stormwater quantity and quality model was used alongside the same dataset. The comparison results for a well-posed rainfall/runoff model showed that the four methods provide similar probability distributions of model parameters, and model prediction intervals. For ill-posed water quality model the differences between the results were much wider; and the paper provides the specific advantages and disadvantages of each method. In relation to computational efficiency (i.e. number of iterations required to generate the probability distribution of parameters), it was found that SCEM-UA and AMALGAM produce results quicker than GLUE in terms of required number of simulations. However, GLUE requires the lowest modelling skills and is easy to implement. All non-Bayesian methods have problems with the way they accept behavioural parameter sets, e.g. GLUE, SCEM-UA and AMALGAM have subjective acceptance thresholds, while MICA has usually problem with its hypothesis on normality of residuals. It is concluded that modellers should select the method which is most suitable for the system they are modelling (e.g. complexity of the model’s structure including the number of parameters), their skill/knowledge level, the available information, and the purpose of their study.




13) Title Worldwide evidence of a unimodal relationship between productivity and plant species richness

Author(s) Chelli, Stefano et al. Year 2015 Journal Science Link http://www.sciencemag.org/content/349/6245/302.short

Abstract The search for predictions of species diversity across environmental gradients has challenged ecologists for decades. The humped-back model (HBM) suggests that plant diversity peaks at intermediate productivity; at low productivity few species can tolerate the environmental stresses, and at high productivity a few highly competitive species dominate. Over time the HBM has become increasingly controversial, and recent studies claim to have refuted it. Here, by using data from coordinated surveys conducted throughout grasslands worldwide and comprising a wide range of site productivities, we provide evidence in support of the HBM pattern at both global and regional extents. The relationships described here provide a foundation for further research into the local, landscape, and historical factors that maintain biodiversity


14) Title Greenhouse-gas payback times for crop-based biofuels Author(s) P. M. F. Elshout; R. Van Zelm; J. Balkovic ; M. Obersteiner; E. Schmid;

R. Skalsky M. Van Der Velde; M. A. J. Huijbregts Year 2015 Journal Nature Climate Change Link http://www.nature.com/nclimate/journal/v5/n6/full/nclimate2642.html

Abstract A global increase in the demand for crop-based biofuels may be met by cropland expansion, and could require the sacrifice of natural vegetation. Such land transformation alters the carbon and nitrogen cycles of the original system, and causes significant greenhouse-gas emissions, which should be considered when assessing the global warming performance of crop-based biofuels. As an indicator of this performance we propose the use of greenhouse-gas payback time (GPBT), that is, the number of years it takes before the greenhouse-gas savings due to displacing fossil fuels with biofuels equal the initial losses of carbon and nitrogen stocks from the original ecosystem. Spatially explicit global GPBTs were derived for biofuel production systems using five different feedstocks (corn, rapeseed, soybean, sugarcane and winter wheat), cultivated under no-input and high-input farm management. Overall, GPBTs were found to range between 1 and 162 years (95% range, median: 19 years) with the longest GPBTs occurring in the tropics. Replacing no-input with high-input farming typically shortened the GPBTs by 45 to 79%. Location of crop cultivation was identified as the primary factor driving variation in GPBTs. This study underscores the importance of using spatially explicit impact assessments to guide biofuel policy.


http://www.sciencemag.org/content/349/6245/302.shorthttp://www.nature.com/nclimate/journal/v5/n6/full/nclimate2642.html


15) Title Integrated life-cycle assessment of electricity-supply scenarios confirms global environmental benefit of low-carbon technologies

Author(s) Hertwich, Edgar G.; Gibon, Thomas; Bouman, Evert A ; Arvesen, Anders; Suh, Sangwon; Bergesen, Joseph D ; Heath, Garvin A.; Ramirez, Andrea; Vega, Mabel I.; Shi, Lei

Year 2014 Journal Proceedings of the National Academy of Sciences of the United States of

America Link http://www.pnas.org/content/112/20/6277

Abstract Decarbonization of electricity generation can support climate-change mitigation and presents an opportunity to address pollution resulting from fossil-fuel combustion. Generally, renewable technologies require higher initial investments in infrastructure than fossil-based power systems. To assess the tradeoffs of increased up-front emissions and reduced operational emissions, we present, to our knowledge, the first global, integrated life-cycle assessment (LCA) of long-term, wide-scale implementation of electricity generation from renewable sources (i.e., photovoltaic and solar thermal, wind, and hydropower) and of carbon dioxide capture and storage for fossil power generation. We compare emissions causing particulate matter exposure, freshwater ecotoxicity, freshwater eutrophication, and climate change for the climate-change-mitigation (BLUE Map) and business-as-usual (Baseline) scenarios of the International Energy Agency up to 2050. We use a vintage stock model to conduct an LCA of newly installed capacity year-by-year for each region, thus accounting for changes in the energy mix used to manufacture future power plants. Under the Baseline scenario, emissions of air and water pollutants more than double whereas the low-carbon technologies introduced in the BLUE Map scenario allow a doubling of electricity supply while stabilizing or even reducing pollution. Material requirements per unit generation for low-carbon technologies can be higher than for conventional fossil generation: 11–40 times more copper for photovoltaic systems and 6–14 times more iron for wind power plants. However, only two years of current global copper and one year of iron production will suffice to build a low-carbon energy system capable of supplying the world's electricity needs in 2050.


http://www.pnas.org/content/112/20/6277


16) Title High nutritional quality is not associated with low greenhouse gas emissions in self-selected diets of French adults

Author(s) Florent Vieux, Louis-Georges Soler, Djilali Touazi, and Nicole Darmon Year 2013 Journal American Journal Of Clinical Nutrition Link http://ajcn.nutrition.org/content/97/3/569

Abstract Background: Healthy diets are supposed to be more environmentally friendly because they rely mainly on plant-based foods, which have lower greenhouse gas emissions (GHGEs) per unit weight than do animal-based foods. Objectives: The objectives were to estimate the GHGEs associated with the consumption of self-selected diets in France and to analyze their relation with the nutritional quality of diets. Design: For each adult in the national dietary Individual and National Survey on Food Consumption (n = 1918), the GHGEs of his or her diet were estimated based on the GHGEs of 391 foods. Highest-nutritional-quality diets were defined as those having simultaneously 1) an energy density below the median, 2) a mean adequacy ratio (MAR) above the median, and 3) a mean excess ratio (MER, percentage of maximum recommended values for nutrients for which intake should be limited) below the median. Results: MAR was positively correlated and MER was negatively correlated with diet-related GHGEs. High-nutritional-quality diets contained more plant-based foods, notably fruit and vegetables, and fewer sweets and salted snacks than did low-quality diets. After adjustment for age, sex, and energy intake, the consumption of sweets and salted snacks was negatively correlated with diet-related GHGEs, whereas the consumption of animal products and of fruit and vegetables was positively associated with them. After adjustment for energy intake, high-nutritional-quality diets had significantly higher GHGEs (+9% and +22% for men and women, respectively) than did low-nutritional-quality diets. Conclusion: Despite containing large amounts of plant-based foods, self-selected diets of the highest nutritional quality are currently not those with the lowest diet-related GHGEs.


17) Title Humanity’s unsustainable environmental footprint Author(s) Hoekstra, Ay; Wiedmann, To Year 2014 Journal Science Link http://www.sciencemag.org/content/344/6188/1114

Abstract Within the context of Earth’s limited natural resources and assimilation capacity, the current environmental footprint of humankind is not sustainable. Assessing land, water, energy, material, and other footprints along supply chains is paramount in understanding the sustainability, efficiency, and equity of resource use from the perspective of producers, consumers, and government. We review current footprints and relate those to maximum sustainable levels, highlighting the need for future work on combining footprints, assessing trade-offs between them, improving computational techniques, estimating maximum sustainable footprint levels, and benchmarking efficiency of resource use. Ultimately, major transformative changes in the global economy are necessary to reduce humanity’s environmental footprint to sustainable levels.

Veantwortliche Prof: S. Hellweg

http://ajcn.nutrition.org/content/97/3/569http://www.sciencemag.org/content/344/6188/1114


18) Title The Role of Automobiles for the Future of Aluminum Recycling Author(s) Modaresi, Roja; Müller, Daniel B Year 2012 Journal Environmental science & technology Link http://pubs.acs.org/doi/abs/10.1021/es300648w

Abstract To reach required product qualities with lowest costs, aluminum postconsumer scrap is currently recycled using strategies of downgrading and dilution, due to difficulties in refining. These strategies depend on a continuous and fast growth of the bottom reservoir of the aluminum downgrading cascade, which is formed by secondary castings, mainly used in automotive applications. A dynamic material flow model for the global vehicle system was developed to assess the likelihood, timing, and extent of a potential scrap surplus. The results demonstrate that a continuation of the above-mentioned strategies will lead to a nonrecyclable scrap surplus by around 2018 ± 5 if no additional measures are taken. The surplus could grow to reach a level of 0.4–2 kg/cap/yr in 2050, corresponding to a loss of energy saving potential of 43–240 TWh/yr electricity. Various intervention options for avoiding scrap surplus are discussed. Effective strategies need to include an immediate and rapid penetration of dramatically improved scrap sorting technologies for end-of-life vehicles and other aluminum applications.


19) Title Anomalous diffusion and multifractality enhance mating encounters in the ocean

Author(s) Seuront, L; Stanley, He Year 2014 Journal Proceedings Of The National Academy Of Sciences Of The United

States Of America Link http://www.pnas.org/content/111/6/2206

Abstract For millimeter-scale aquatic crustaceans such as copepods, ensuring reproductive success is a challenge as potential mates are often separated by hundreds of body lengths in a 3D environment. At the evolutionary scale, this led to the development of remote sensing abilities and behavioral strategies to locate, to track, and to capture a mate. Chemoreception plays a crucial role in increasing mate encounter rates through pheromone clouds and pheromone trails that can be followed over many body lengths. Empirical evidence of trail following behavior is, however, limited to laboratory experiments conducted in still water. An important open question concerns what happens in the turbulent waters of the surface ocean. We propose that copepods experience, and hence react to, a bulk-phase water pheromone concentration. Here we investigate the mating behavior of two key copepod species, Temora longicornis and Eurytemora affinis, to assess the role of background pheromone concentration and the relative roles played by males and females in mating encounters. We find that both males and females react to background pheromone concentration and exhibit both innate and acquired components in their mating strategies. The emerging swimming behaviors have stochastic properties that depend on pheromone concentration, sex, and species, are related to the level of reproductive experience of the individual tested, and significantly diverge from both the Lévy and Brownian models identified in predators searching for low- and high-density prey. Our results are consistent with an adaptation to increase mate encounter rates and hence to optimize reproductive fitness and success.

Verantwortlicher Prof: M. Holzner

http://pubs.acs.org/doi/abs/10.1021/es300648whttp://www.pnas.org/content/111/6/2206


20) Title Solutions to the Public Goods Dilemma in Bacterial Biofilms Author(s) Drescher, K; Nadell, CD; Stone, Ha; Wingreen, Ns; Bassler, Bl Year 2014 Journal Current Biology Link http://www.sciencedirect.com/science/article/pii/S0960982213012712

Abstract Bacteria frequently live in densely populated surface-bound communities, termed biofilms [1, 2, 3 and 4]. Biofilm-dwelling cells rely on secretion of extracellular substances to construct their communities and to capture nutrients from the environment [5]. Some secreted factors behave as cooperative public goods: they can be exploited by nonproducing cells [6, 7, 8, 9, 10 and 11]. The means by which public-good-producing bacteria avert exploitation in biofilm environments are largely unknown. Using experiments with Vibrio cholerae, which secretes extracellular enzymes to digest its primary food source, the solid polymer chitin, we show that the public goods dilemma may be solved by two very different mechanisms: cells can produce thick biofilms that confine the goods to producers, or fluid flow can remove soluble products of chitin digestion, denying access to nonproducers. Both processes are unified by limiting the distance over which enzyme-secreting cells provide benefits to neighbors, resulting in preferential benefit to nearby clonemates and allowing kin selection to favor public good production. Our results demonstrate new mechanisms by which the physical conditions of natural habitats can interact with bacterial physiology to promote the evolution of cooperation.

Verantwortlicher Prof: M. Holzner

21) Title Critical and sustainable fluxes: Theory, experiments and applications

Author(s) Bacchin, P. ; Aimar, P. ; Field, R.W. Year 2006 Journal Journal of Membrane Science Link http://www.sciencedirect.com/science/article/pii/S037673880600250X

Abstract Over the last 10 years, numerous membrane filtration data have been viewed through the lens of the concept of critical flux. This concept, used in a number of different ways often without explicit redefinition, is here clarified both theoretically and from an experimental viewpoint. A link is made with the concept of sustainable flux and an approach given for the determination of the apparent sustainable flux. To retain the utility of the critical flux concepts, it is emphasised firstly that the strong form and weak form of the critical flux, Jcs and Jcw, must be evaluated via a check on whether or not the overall resistance has remained invariant. Secondly, the critical flux for irreversibility, Jci, has a sound theoretical basis; it represents the shift from repulsive interaction (dispersed matter—polarised layer) to attractive interaction (condensed matter—deposit). The various methods for measuring critical flux and the influence of membrane and suspension properties on critical flux are reviewed. Dispersive forces that are the key to the existence of a critical flux are discussed. The concept of a critical concentration for phase transition is also introduced. For theoreticians and experimentalists, this and the clarified concept of a small set of critical fluxes will continue to provide a valuable framework. But in addition, and especially for membrane users dealing with industrial process streams, the concept of a sustainable flux (which has evolved from critical flux thinking) is of a great utility. Above the sustainable flux (dependent on hydrodynamics, feed conditions and process time), the rate of fouling is economically and environmentally unsustainable.

Verantwortlicher Prof: E. Morgenroth

http://www.sciencedirect.com/science/article/pii/S0960982213012712http://www.sciencedirect.com/science/article/pii/S037673880600250X


22) Title Flexible Community Structure Correlates with Stable Community Function in Methanogenic Bioreactor Communities Perturbed by Glucose

Author(s) Fernandez, Ana S. ; Hashsham, Syed A. ; Dollhopf, Sherry L. ; Raskin, Lutgarde ; Glagoleva, Olga ; Dazzo, Frank B. ; Hickey, Robert F. ; Criddle, Craig S. ; Tiedje, James M

Year 2000 Journal Applied and Environmental Microbiology Link http://aem.asm.org/content/66/9/4058

Abstract Methanogenic bioreactor communities were used as model ecosystems to evaluate the relationship between functional stability and community structure. Replicated methanogenic bioreactor communities with two different community structures were established. The effect of a substrate loading shock on population dynamics in each microbial community was examined by using morphological analysis, small-subunit (SSU) rRNA oligonucleotide probes, amplified ribosomal DNA (rDNA) restriction analysis (ARDRA), and partial sequencing of SSU rDNA clones. One set of replicated communities, designated the high-spirochete (HS) set, was characterized by good replicability, a high proportion of spiral and short thin rod morphotypes, a dominance of spirochete-related SSU rDNA genes, and a high percentage ofMethanosarcina-related SSU rRNA. The second set of communities, designated the low-spirochete (LS) set, was characterized by incomplete replicability, higher morphotype diversity dominated by cocci, a predominance of Streptococcus-related and deeply branching Spirochaetales-related SSU rDNA genes, and a high percentage of Methanosaeta-related SSU rRNA. In the HS communities, glucose perturbation caused a dramatic shift in the relative abundance of fermentative bacteria, with temporary displacement of spirochete-related ribotypes byEubacterium-related ribotypes, followed by a return to the preperturbation community structure. The LS communities were less perturbed, with Streptococcus-related organisms remaining prevalent after the glucose shock, although changes in the relative abundance of minor members were detected by morphotype analysis. A companion paper demonstrates that the more stable LS communities were less functionally stable than the HS communities (S. A. Hashsham, A. S. Fernandez, S. L. Dollhopf, F. B. Dazzo, R. F. Hickey, J. M. Tiedje, and C. S. Criddle, Appl. Environ. Microbiol. 66:4050–4057, 2000).


23) Title Can Direct Conversion of Used Nitrogen to New Feed and Protein Help Feed the World?

Author(s) Matassa, Silvio ; Verstraete, Willy ; Matassa, Silvio ; Verstraete, Willy ; Verstraete, Willy ; Batstone, Damien J. ; Hülsen, Tim ; Batstone, Damien J. ; Hülsen, Tim ; Schnoor, Jerald

Year 2015 Journal Environmental Science and Technology Link http://pubs.acs.org/doi/abs/10.1021/es505432w

Abstract The increase in the world population, vulnerability of conventional crop production to climate change, and population shifts to megacities justify a re-examination of current methods of converting reactive nitrogen to dinitrogen gas in sewage and waste treatment plants. Indeed, by up-grading treatment plants to factories in which the incoming materials are first deconstructed to units such as ammonia, carbon dioxide and clean minerals, one can implement a highly intensive and efficient microbial resynthesis process in which the used nitrogen is harvested as microbial protein (at efficiencies close to 100%). This can be used for animal feed and food purposes. The technology for recovery of reactive nitrogen as microbial protein is available but a change of mindset needs to be achieved to make such recovery acceptable.


http://aem.asm.org/content/66/9/4058http://pubs.acs.org/doi/abs/10.1021/es505432w


24) Title Emerging contaminants of public health significance as water quality indicator compounds in the urban water cycle

Author(s) Pal, Amrita ; He, Yiliang ; Jekel, Martin ; Reinhard, Martin ; Gin, Karina Yew-Hoong

Year 2014 Journal Environment International Link http://www.sciencedirect.com/science/article/pii/S0160412014001767

Abstract The contamination of the urban water cycle (UWC) with a wide array of emerging organic compounds (EOCs) increases with urbanization and population density. To produce drinking water from the UWC requires close examination of their sources, occurrence, pathways, and health effects and the efficacy of wastewater treatment and natural attenuation processes that may occur in surface water bodies and groundwater. This paper researches in details the structure of the UWC and investigates the routes by which the water cycle is increasingly contaminated with compounds generated from various anthropogenic activities. Along with a thorough survey of chemicals representing compound classes such as hormones, antibiotics, surfactants, endocrine disruptors, human and veterinary pharmaceuticals, X-ray contrast media, pesticides and metabolites, disinfection-by-products, algal toxins and taste-and-odor compounds, this paper provides a comprehensive and holistic review of the occurrence, fate, transport and potential health impact of the emerging organic contaminants of the UWC. This study also illustrates the widespread distribution of the emerging organic contaminants in the different aortas of the ecosystem and focuses on future research needs.


25) Title Reducing sewer corrosion through integrated urban water management

Author(s) Pikaar, I ; Sharma, Kr ; Hu, Sh ; Gernjak, W ; Keller, J ; Yuan, Zg Year 2014 Journal Science Link http://www.sciencemag.org/content/345/6198/812

Abstract Sewer systems are among the most critical infrastructure assets for modern urban societies and provide essential human health protection. Sulfide-induced concrete sewer corrosion costs billions of dollars annually and has been identified as a main cause of global sewer deterioration. We performed a 2-year sampling campaign in South East Queensland (Australia), an extensive industry survey across Australia, and a comprehensive model-based scenario analysis of the various sources of sulfide. Aluminum sulfate addition during drinking water production contributes substantially to the sulfate load in sewage and indirectly serves as the primary source of sulfide. This unintended consequence of urban water management structures could be avoided by switching to sulfate-free coagulants, with no or only marginal additional expenses compared with the large potential savings in sewer corrosion costs.




26) Title Mineral CO2 sequestration by environmental biotechnological processes

Author(s) Salek, Shiva S ; Kleerebezem, Robbert ; Jonkers, Henk M ; Witkamp, Geert-Jan ; Van Loosdrecht, Mark C M

Year 2013 Journal Trends in biotechnology Link http://www.sciencedirect.com/science/article/pii/S0167779913000176

Abstract CO2 sequestration may be an avenue to mitigate climate change. CO2 sequestration by mineral carbonation can be achieved by the reaction of CO2 with alkaline silicates. Here, we evaluate how alkaline silicate mineral-based CO2 sequestration can be achieved using environmental biotechnological processes. Several biotechnological processes rely on the sequence of (i) an acid-producing reaction such as nitrification and anaerobic fermentation and (ii) an alkalinity-producing reaction such as denitrification and methanogenesis. Whereas the acid-producing reaction can be used to enhance the dissolution of, for example, alkaline calcium silicates, the subsequent alkalinity-producing step can precipitate CaCO3. We quantitatively evaluate the potential of these processes for CO2 sequestration and propose that optimization of these processes could contribute to climate change mitigation strategies.


27) Title Recovery of Freshwater from Wastewater: Upgrading Process Configurations To Maximize Energy Recovery and Minimize Residuals

Author(s) Scherson, Yaniv D. ; Criddle, Craig S. Year 2014 Journal Environmental Science and Technology Link http://pubs.acs.org/doi/abs/10.1021/es501701s

Abstract Analysis of conventional and novel wastewater treatment configurations reveals large differences in energy consumed or produced and solids generated per cubic meter of domestic wastewater treated. Complete aerobic BOD removal consumes 0.45 kWh and produces 153 g of solids, whereas complete anaerobic treatment produces 0.25 kWh and 80 g of solids. Emerging technologies, that include short-circuit nitrogen removal (SHARON, CANON with Anammox, CANDO) and mainstream anaerobic digestion, can potentially remove both BOD and nitrogen with an energy surplus of 0.17 kWh and production of 95 g of solids. Heat from biogas combustion can completely dry the solids, and these solids can be converted to syngas without imported energy. Syngas combustion can produce ∼0.1 kWh with an inorganic residue of just 10 g. If salt is removed, freshwater can be recovered with net production of electrical energy from methane (0.03–0.13 kWh) and syngas (∼0.1 kWh) and an inorganic residue of ∼0.1-0.3 kg as brine. Current seawater desalination requires 3–4 kWh (thermodynamic limit of 1 kWh) and results in an inorganic residue of ∼35 kg as brine.


http://www.sciencedirect.com/science/article/pii/S0167779913000176http://pubs.acs.org/doi/abs/10.1021/es501701s


28) Title Navigating Wastewater Energy Recovery Strategies: A Life Cycle Comparison of Anaerobic Membrane Bioreactor and Conventional Treatment Systems with Anaerobic Digestion

Author(s) Smith, AL ; Stadler, Lb ; Cao, L ; Love, Ng ; Raskin, L ; Skerlos, SJ Year 2014 Journal Environmental Science & Technology Link http://pubs.acs.org/doi/abs/10.1021/es5006169

Abstract The objective of this study was to evaluate emerging anaerobic membrane bioreactor (AnMBR) technology in comparison with conventional wastewater energy recovery technologies. Wastewater treatment process modeling and systems analyses were combined to evaluate the conditions under which AnMBR may produce more net energy and have lower life cycle environmental emissions than high rate activated sludge with anaerobic digestion (HRAS+AD), conventional activated sludge with anaerobic digestion (CAS+AD), and an aerobic membrane bioreactor with anaerobic digestion (AeMBR+AD). For medium strength domestic wastewater treatment under baseline assumptions at 15 °C, AnMBR recovered 49% more energy as biogas than HRAS+AD, the most energy positive conventional technology considered, but had significantly higher energy demands and environmental emissions. Global warming impacts associated with AnMBR were largely due to emissions of effluent dissolved methane. For high strength domestic wastewater treatment, AnMBR recovered 15% more net energy than HRAS+AD, and the environmental emissions gap between the two systems was reduced. Future developments of AnMBR technology in low energy fouling control, increased flux, and management of effluent methane emissions would make AnMBR competitive with HRAS+AD. Rapid advancements in AnMBR technology must continue to achieve its full economic and environmental potential as an energy recovery strategy for domestic wastewater.


29) Title a) Local perspectives on water b) Fresh water goes global

In diesem Fall sollen beide Publikationen gemeinsam diskutiert werden. Die beiden Publikationen wurden auch gemeinsam publiziert.

Author(s) a) Hering, J. G.; Sedlak, D. L.; Tortajada, C.; Biswas, A. K.; Niwagaba, C.; Breu, T.

b) Vorosmarty, C. J.; Hoekstra, A. Y.; Bunn, S. E.; Conway, D.; Gupta, J.

Year 2015 Journal Science Link a) http://www.sciencemag.org/content/349/6247/479

b) http://www.sciencemag.org/content/349/6247/478.2

Abstract a) A global perspective on water management predominates in high-level policy discussions. This has the advantage that over-arching issues can be highlighted and international resources mobilized. But water issues arise from local conditions and can only be resolved by people and institutions with local authority and responsibility. High-level policies can only have meaningful impact if they are informed by and responsive to local and regional contexts. In keeping with the principle of subsidiarity, high-level policy-making should support local and regional interests, efforts, and policies.

b) Although water problems have been traditionally perceived, understood, and acted on locally, recent progress in Earth-system simulation, remote sensing, and analysis of water governance is producing new perspectives on fresh water. The advances reveal previously unrecognized global forces at work driving local-scale problems. The stage is reset for water research and policy-making.


http://pubs.acs.org/doi/abs/10.1021/es5006169http://www.sciencemag.org/content/349/6247/479http://www.sciencemag.org/content/349/6247/478.2


30) Title Influence of data collection schemes on the Life Cycle Assessment of a municipal wastewater treatment plant

Author(s) Yoshida, H ; Clavreul, J ; Scheutz, C ; Christensen, Th Year 2014 Journal Water Research Link http://www.sciencedirect.com/science/article/pii/S0043135414002048

Abstract A Life Cycle Assessment (LCA) of a municipal wastewater treatment plant (WWTP) was conducted to illustrate the effect of an emission inventory data collection scheme on the outcomes of an environmental impact assessment. Due to their burden in respect to data collection, LCAs often rely heavily on existing emission and operational data, which are gathered under either compulsory monitoring or reporting requirements under law. In this study, an LCA was conducted using three input data sources: Information compiled under compulsory disclosure requirements (the European Pollutant Release and Transfer Registry), compliance with national discharge limits, and a state-of-the-art emission data collection scheme conducted at the same WWTP. Parameter uncertainty for each collection scheme was assessed through Monte Carlo simulation. The comparison of the results confirmed that LCA results depend heavily on input data coverage. Due to the threshold on reporting value, the E-PRTR did not capture the impact for particulate matter emission, terrestrial acidification, or terrestrial eutrophication. While the current practice can capture more than 90% of non-carcinogenic human toxicity and marine eutrophication, an LCA based on the data collection scheme underestimates impact potential due to limitations of substance coverage. Besides differences between data collection schemes, the results showed that 3–13,500% of the impacts came from background systems, such as from the provisioning of fuel, electricity, and chemicals, which do not need to be disclosed currently under E-PRTR. The incidental release of pollutants was also assessed by employing a scenario-based approach, the results of which demonstrated that these non-routine emissions could increase overall WWTP greenhouse gas emissions by between 113 and 210%. Overall, current data collection schemes have the potential to provide standardized data collection and form the basis for a sound environmental impact assessment, but several improvements are recommended, including the additional collection of energy and chemical usage data, the elimination of a reporting threshold, the expansion of substance coverage, and the inclusion of non-point fugitive gas emissions.


31) Title Disruption of Vertical Motility by Shear Triggers Formation of Thin Phytoplankton Layers

Author(s) Durham, Wm; Kessler, Jo; Stocker, R Year 2009 Journal Science Link http://www.sciencemag.org/content/323/5917/1067

Abstract Thin layers of phytoplankton are important hotspots of ecological activity that are found in the coastal ocean, meters beneath the surface, and contain cell concentrations up to two orders of magnitude above ambient concentrations. Current interpretations of their formation favor abiotic processes, yet many phytoplankton species found in these layers are motile. We demonstrated that layers formed when the vertical migration of phytoplankton was disrupted by hydrodynamic shear. This mechanism, which we call gyrotactic trapping, can be responsible for the thin layers of phytoplankton commonly observed in the ocean. These results reveal that the coupling between active microorganism motility and ambient fluid motion can shape the macroscopic features of the marine ecological landscape.

Verantwortlicher Prof: R. Stocker



32) Title Trade-Offs of Chemotactic Foraging in Turbulent Water Author(s) Taylor, Jr; Stocker, R Year 2012 Journal Science Link http://www.sciencemag.org/content/338/6107/675

Abstract Bacteria play an indispensable role in marine biogeochemistry by recycling dissolved organic matter. Motile species can exploit small, ephemeral solute patches through chemotaxis and thereby gain a fitness advantage over nonmotile competitors. This competition occurs in a turbulent environment, yet turbulence is generally considered inconsequential for bacterial uptake. In contrast, we show that turbulence affects uptake by stirring nutrient patches into networks of thin filaments that motile bacteria can readily exploit. We find that chemotactic motility is subject to a trade-off between the uptake benefit due to chemotaxis and the cost of locomotion, resulting in an optimal swimming speed. A second trade-off results from the competing effects of stirring and mixing and leads to the prediction that chemotaxis is optimally favored at intermediate turbulence intensities.


33) Title Rapid chemotactic response enables marine bacteria to exploit ephemeral microscale nutrient patches

Author(s) Stocker, R; Seymour, Jr; Samadani, A; Hunt, De; Polz, Mf Year 2008 Journal Proceedings Of The National Academy Of Sciences Of The United


Abstract Because ocean water is typically resource-poor, bacteria may gain significant growth advantages if they can exploit the ephemeral nutrient patches originating from numerous, small sources. Although this interaction has been proposed to enhance biogeochemical transformation rates in the ocean, it remains questionable whether bacteria are able to efficiently use patches before physical mechanisms dissipate them. Here we show that the rapid chemotactic response of the marine bacterium Pseudoalteromonas haloplanktis substantially enhances its ability to exploit nutrient patches before they dissipate. We investigated two types of patches important in the ocean: nutrient pulses and nutrient plumes, generated for example from lysed algae and sinking organic particles, respectively. We used microfluidic devices to create patches with environmentally realistic dimensions and dynamics. The accumulation of P. haloplanktis in response to a nutrient pulse led to formation of bacterial hot spots within tens of seconds, resulting in a 10-fold higher nutrient exposure for the fastest 20% of the population compared with nonmotile cells. Moreover, the chemotactic response of P. haloplanktis was >10 times faster than the classic chemotaxis model Escherichia coli, leading to twice the nutrient exposure. We demonstrate that such rapid response allows P. haloplanktis to colonize nutrient plumes for realistic particle sinking speeds, with up to a 4-fold nutrient exposure compared with nonmotile cells. These results suggest that chemotactic swimming strategies of marine bacteria in patchy nutrient seascapes exert strong influence on carbon turnover rates by triggering the formation of microscale hot spots of bacterial productivity.


http://www.sciencemag.org/content/338/6107/675http://www.pnas.org/content/105/11/4209


34) Title Bacterial transport suppressed by fluid shear Author(s) Roberto Rusconi, Jeffrey S. Guasto & Roman Stocker Year 2014 Journal Nature Physics Link http://www.nature.com/nphys/journal/v10/n3/abs/nphys2883.html

Abstract Bacteria often live in dynamic fluid environments1, 2, 3

and flow can affect fundamental microbial processes such as nutrient uptake

1, 4 and infection

5. However, little is known

about the consequences of the forces and torques associated with fluid flow on bacteria. Through microfluidic experiments, we show that fluid shear produces strong spatial heterogeneity in suspensions of motile bacteria, characterized by up to 70% cell depletion from low-shear regions due to ‘trapping’ in high-shear regions. Two mathematical models and a scaling analysis accurately capture these observations, including the maximal depletion at mean shear rates of 2.5–10 s

−1, and reveal that

trapping by shear originates from the competition between the cell alignment with the flow and the stochasticity in the swimming orientation. We show that this shear-induced trapping directly impacts widespread bacterial behaviours, by hampering chemotaxis and promoting surface attachment. These results suggest that the hydrodynamic environment may directly affect bacterial fitness and should be carefully considered in the study of microbial processes.


35) Title Life at low Reynolds number Author(s) E.M. Purcell Year 1977 Journal American Journal of Physics Link http://scitation.aip.org/content/aapt/journal/ajp/45/1/10.1119/1.10903

Abstract Editor’s note: This is a reprint (slightly edited) of a paper of the same title that appeared in the book Physics and Our World A Symposium in Honor of Victor F. Weisskopf, published by the American Institute of Physics (1976). The personal tone of the original talk has been preserved in the paper, which was itself a slightly edited transcript of a tape. The figures reproduce transparencies used in the talk. The demonstration involved a tall rectangular transparent vessel of corn syrup, projected by an overhead projector turned on its side. Some essential hand waving could not be reproduced.


http://www.nature.com/nphys/journal/v10/n3/abs/nphys2883.htmlhttp://scitation.aip.org/content/aapt/journal/ajp/45/1/10.1119/1.10903


36) Title Turbulence and the diffusive layers around small organisms Author(s) Lazier, Jrn; Mann, Kh Year 1989 Journal Deep Sea Research Part A. Oceanographic Research Papers Link http://www.sciencedirect.com/science/article/pii/019801498990068X

Abstract We consider whether the diffusion of substances to and from a small spherical organism that is motionless relative to the surrounding water is significantly affected by the turbulent motions in the water. Viscosity, by smoothing out turbulent eddies less than a few millimeters across, dictates that the flow of nutrients and wastes to and from a very small organism must occur by molecular diffusion through a thin surrounding boundary layer. Motion of the organism relative to the water through sinking or swimming distorts this boundary layer. This alters the gradients and causes a fairly well understood increase in diffusive flux. The effect of turbulent motion on the flux, however, is less well understood. We first clarify the relationship between the size of the smallest turbulent eddies and the Kolmogorov or viscous length and go on to contend that turbulent motion over the small distances near small organisms is manifested as a linear velocity gradient whose magnitude is determined by the rate of turbulent energy dissipation. Knowing the shear enables us to calculate, from the experimental results of Purcel (1978, Journal of Fluid Mechanics, 84, 551–559), the quantitative effect of the turbulence on the diffusive flux to and from an idealized spherical organism. For motionless cells 100 μm in diameter, high levels of turbulence (dissipation rate 10−6 W kg

−1_ produce a ⋍2% increase in flux. This escalates to a

100% increase for cells ⋍1 mm in diameter. Our results also lead to the conclusion that the microzones of increased nutrient levels surrounding small organisms, proposed by Mitchellet al. (1985, Nature, 316, 58–59), are much more robust than they suggested.


37) Title Flows driven by flagella of multicellular organisms enhance long-range molecular transport

Author(s) Short, MB; Solari, Ca; Ganguly, S; Powers, Tr; Kessler, J; Goldstein, Re Year 2006 Journal Proceedings Of The National Academy Of Sciences Of The United


Abstract Evolution from unicellular organisms to larger multicellular ones requires matching their needs to the rate of exchange of molecular nutrients with the environment. This logistic problem poses a severe constraint on development. For organisms whose body plan is a spherical shell, such as the volvocine green algae, the current (molecules per second) of needed nutrients grows quadratically with radius, whereas the rate at which diffusion alone exchanges molecules grows linearly, leading to a bottleneck radius beyond which the diffusive current cannot meet metabolic demands. By using Volvox carteri, we examine the role that advection of fluid by the coordinated beating of surface-mounted flagella plays in enhancing nutrient uptake and show that it generates a boundary layer of concentration of the diffusing solute. That concentration gradient produces an exchange rate that is quadratic in the radius, as required, thus circumventing the bottleneck and facilitating evolutionary transitions to multicellularity and germ–soma differentiation in the volvocalean green algae.


http://www.sciencedirect.com/science/article/pii/019801498990068Xhttp://www.pnas.org/content/103/22/8315


38) Title A multi-source satellite data approach for modelling Lake Turkana water level: calibration and validation using satellite altimetry data

Author(s) N. M. Velpuri; G. B. Senay; K. O. Asante Year 2012 Journal Hydrology and Earth System Sciences Link http://www.hydrol-earth-syst-sci.net/16/1/2012/hess-16-1-2012.html

Abstract Lake Turkana is one of the largest desert lakes in the world and is characterized by high degrees of inter- and intra-annual fluctuations. The hydrology and water balance of this lake have not been well understood due to its remote location and unavailability of reliable ground truth datasets. Managing surface water resources is a great challenge in areas where in-situ data are either limited or unavailable. In this study, multi-source satellite-driven data such as satellite-based rainfall estimates, modelled runoff, evapotranspiration, and a digital elevation dataset were used to model Lake Turkana water levels from 1998 to 2009. Due to the unavailability of reliable lake level data, an approach is presented to calibrate and validate the water balance model of Lake Turkana using a composite lake level product of TOPEX/Poseidon, Jason-1, and ENVISAT satellite altimetry data. Model validation results showed that the satellite-driven water balance model can satisfactorily capture the patterns and seasonal variations of the Lake Turkana water level fluctuations with a Pearson's correlation coefficient of 0.90 and a Nash-Sutcliffe Coefficient of Efficiency (NSCE) of 0.80 during the validation period (2004–2009). Model error estimates were within 10% of the natural variability of the lake. Our analysis indicated that fluctuations in Lake Turkana water levels are mainly driven by lake inflows and over-the-lake evaporation. Over-the-lake rainfall contributes only up to 30% of lake evaporative demand. During the modelling time period, Lake Turkana showed seasonal variations of 1–2 m. The lake level fluctuated in the range up to 4 m between the years 1998–2009. This study demonstrated the usefulness of satellite altimetry data to calibrate and validate the satellite-driven hydrological model for Lake Turkana without using any in-situ data. Furthermore, for Lake Turkana, we identified and outlined opportunities and challenges of using a calibrated satellite-driven water balance model for (i) quantitative assessment of the impact of basin developmental activities on lake levels and for (ii) forecasting lake level changes and their impact on fisheries. From this study, we suggest that globally available satellite altimetry data provide a unique opportunity for calibration and validation of hydrologic models in ungauged basins.

Verantwortlicher Prof: P. Molnar

39) Title Impact of Humans on the Flux of Terrestrial Sediment to the Global Coastal Ocean

Author(s) Syvitski, James P. M.; Vorosmarty, Charles J.; Kettner, Albert J.; Green, Pamela

Year 2005 Journal Science Link http://www.sciencemag.org/content/308/5720/376

Abstract Here we provide global estimates of the seasonal flux of sediment, on a river-by-river basis, under modern and prehuman conditions. Humans have simultaneously increased the sediment transport by global rivers through soil erosion (by 2.3 ± 0.6 billion metric tons per year), yet reduced the flux of sediment reaching the world's coasts (by 1.4 ± 0.3 billion metric tons per year) because of retention within reservoirs. Over 100 billion metric tons of sediment and 1 to 3 billion metric tons of carbon are now sequestered in reservoirs constructed largely within the past 50 years. African and Asian rivers carry a greatly reduced sediment load; Indonesian rivers deliver much more sediment to coastal areas.


http://www.hydrol-earth-syst-sci.net/16/1/2012/hess-16-1-2012.htmlhttp://www.sciencemag.org/content/308/5720/376


40) Title Trends in flood magnitude, frequency and seasonality in Germany in the period 1951–2002

Author(s) Petrow, Theresia; Merz, Bruno Year 2009 Journal Journal of Hydrology Link http://www.sciencedirect.com/science/article/pii/S0022169409001917

Abstract During the last decades several destructive floods in Germany led to the impression that the frequency and/or magnitude of flooding has been increasing. In this study, flood time series are derived and analyzed for trends for 145 discharge gauges in Germany. A common time period of 52 years (1951–2002) is used. In order to obtain a country-wide picture, the gauges are rather homogeneously distributed across Germany. Eight flood indicators are studied, which are drawn from annual maximum series and peak over threshold series. Our analysis detects significant flood trends (at the 10% significance level) for a considerable fraction of basins. In most cases, these trends are upward; decreasing flood trends are rarely found and are not field-significant. Marked differences emerge when looking at the spatial and seasonal patterns. Basins with significant trends are spatially clustered. Changes in flood behavior in northeast Germany are small. Most changes are detected for sites in the west, south and center of Germany. Further, the seasonal analysis reveals larger changes for winter compared to summer. Both, the spatial and seasonal coherence of the results and the missing relation between significant changes and basin area, suggest that the observed changes in flood behavior are climate-driven.


41) Title Rainfall erosivity in Europe Author(s) Panagos P. et al. Year 2015 Journal Science of the Total Environment Link http://www.sciencedirect.com/science/article/pii/S004896971500011X

Abstract Rainfall is one the main drivers of soil erosion. The erosive force of rainfall is expressed as rainfall erosivity. Rainfall erosivity considers the rainfall amount and intensity, and is most commonly expressed as the R-factor in the USLE model and its revised version, RUSLE. At national and continental levels, the scarce availability of data obliges soil erosion modellers to estimate this factor based on rainfall data with only low temporal resolution (daily, monthly, annual averages). The purpose of this study is to assess rainfall erosivity in Europe in the form of the RUSLE R-factor, based on the best available datasets. Data have been collected from 1541 precipitation stations in all European Union (EU) Member States and Switzerland, with temporal resolutions of 5 to 60 min. The R-factor values calculated from precipitation data of different temporal resolutions were normalised to R-factor values with temporal resolutions of 30 min using linear regression functions. Precipitation time series ranged from a minimum of 5 years to a maximum of 40 years. The average time series per precipitation station is around 17.1 years, the most datasets including the first decade of the 21st century. Gaussian Process Regression (GPR) has been used to interpolate the R-factor station values to a European rainfall erosivity map at 1 km resolution. The covariates used for the R-factor interpolation were climatic data (total precipitation, seasonal precipitation, precipitation of driest/wettest months, average temperature), elevation and latitude/longitude. The mean R-factor for the EU plus Switzerland is 722 MJ mm ha

− 1 h

− 1 yr

− 1, with the highest values (> 1000 MJ mm ha

− 1 h

− 1 yr

− 1) in the

Mediterranean and alpine regions and the lowest (< 500 MJ mm ha− 1

h− 1

yr− 1

) in the Nordic countries. The erosivity density (erosivity normalised to annual precipitation amounts) was also the highest in Mediterranean regions which implies high risk for erosive events and floods.


http://www.sciencedirect.com/science/article/pii/S0022169409001917http://www.sciencedirect.com/science/article/pii/S004896971500011X


42) Title Revealing the natural complexity of fluvial morphology through 2D hydrodynamic delineation of river landforms

Author(s) Wyrick, J.R.; Senter, A.E.; Pasternack, G.B. Year 2014 Journal Geomorphology, Link http://www.sciencedirect.com/science/article/pii/S0169555X13006211

Abstract Fluvial landforms at the morphological-unit scale (~ 1–10 channel widths) are typically delineated and mapped either by breaking up the one-dimensional longitudinal profile with no accounting of lateral variations or by manually classifying surface water patterns and two-dimensional areal extents in situ or with aerial imagery. Mapping errors arise from user subjectivity, varying surface water patterns when the same area is observed at different discharges and viewpoints, and difficulty in creating a complete map with no gaps or overlaps in delineated polygons. This study presents a new theory for delineating and mapping channel landforms at the morphological-unit scale that eliminates in-field subjective decision making, adds full transparency for map users, and enables future systemic alterations without having to remap in the field. Delineation is accomplished through a few basic steps. First, near-census topographic and bathymetric data are used in a two-dimensional hydrodynamic model to create meter-scale depth and velocity rasters for a representative base flow. Second, expert judgment and local knowledge determine the number and nomenclature of landform types as well as the range of base flow depth and velocity over each type. This step does require subjectivity, but it is transparent and adjustable at any time. Third, the hydraulic landform classification is applied to hydraulic rasters to quickly, completely, and objectively map the planform pattern of laterally explicit landforms. Application of this theory will reveal the true natural complexity, yet systematic organization, of channel morphology.


43) Title Optimization of Multipurpose Reservoir Systems Using Power Market Models

Author(s) Pereira-Cardenal, S.et al. Year 2015 Journal Journal of Water Resources Planning and Management Link http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29WR.1943-

5452.0000500

Abstract Hydroeconomic models have been used to determine policies for efficient allocation of scarce water resources. Hydropower benefits are typically represented through exogenous electricity prices, but these do not consider the effect that the power market can have on the hydropower release policy and vice versa. To improve the representation of hydropower benefits in hydroeconomic models, an application of stochastic dynamic programming, known as the water value method, was used to maximize irrigation benefits while minimizing the costs of power generation within a power market. The method yields optimal operation rules that maximize current and expected future benefits as a function of reservoir level, week of the year, and inflow state. The method was tested on the Iberian Peninsula and performed better than traditional approaches that use exogenous prices: resulting operation rules were more realistic and sensitive to hydrological variability. Internally calculated hydropower prices provided better results than exogenous hydropower prices and can therefore improve the representation of hydropower benefits in hydroeconomic models.

Verantwortlicher Prof: P. Burlando

http://www.sciencedirect.com/science/article/pii/S0169555X13006211http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29WR.1943-5452.0000500http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29WR.1943-5452.0000500


44) Title Deriving Optimal Daily Reservoir Operation Scheme with Consideration of Downstream Ecological Hydrograph Through A Time-Nested Approach

Author(s) Chen, Duan; Li, Ruonan; Chen, Qiuwen; Cai, Desuo Year 2015 Journal Water Resources Management Link http://link.springer.com/article/10.1007/s11269-015-1005-z

Abstract The ecological flow requirement (EFR) during special life stages of species, for instance the fish spawning period, concerns not only the flow rate, but also daily changes in the flow rate. Therefore, it is more appropriate to optimize ecologically-friendly reservoir operation on a daily base. Directly formulating and solving a daily-based optimization model would involve a large number of decision variables as well as constraints, which may lead to unfavourable time consumption and unreliable solutions. This study proposes a time-nested approach to derive an optimal daily reservoir operation scheme with consideration of the downstream ecological hydrograph. It scales down the decision variables from monthly-base to 10-day base and finally to daily-base. The proposed method was applied to two cascaded reservoirs in the Yalong River in southwest China, where a daily ecological flow is required to conserve the habitats of an indigenous fish Schizothorax chongi (S. chongi). The results showed that the developed method could efficiently derive a daily optimal operational scheme with the consideration of downstream EFR for fish habitat conservation. In addition, the method greatly improves global searching ability in dealing with complex optimization problems.


45) Title Simulating spatiotemporal variability of blue and green water resources availability with uncertainty analysis

Author(s) Zuo, Depeng et al. Year 2015 Journal Hydrological Processes Link http://onlinelibrary.wiley.com/doi/10.1002/hyp.10307/abstract

Abstract Due to rapid socioeconomic development, continuous population growth and urbanization, the world is facing a severe shortage of fresh water, particularly in arid and semi-arid regions. A lack of water will put pressure on agricultural production, water pollution, as well as eco-environmental degradation. Traditional water resources assessment mainly focused on blue water, ignoring green water. Therefore, analysis of spatiotemporal distribution of blue and green water resources in arid and semi-arid regions is of great significance for water resources planning and management, especially for harmonizing agricultural water use and eco-environmental water requirements. This study applied the Soil and Water Assessment Tool (SWAT) model and the Sequential Uncertainty Fitting algorithm (SUFI-2) to calibrate and validate the SWAT model based on river discharges in the Wei River, the largest tributary of the Yellow River in China. Uncertainty analysis was also performed to quantify the blue and green water resources availability at different spatial scales. The results showed that most parts of the Wei River basin (WRB) experienced a decrease in blue water resources during the recent 50 years with a minimum value in the 1990s. The decrease is particularly significant in the most southern part of the WRB (the Guanzhong Plain), one of the most important grain production bases in China. Variations of green water flow and green water storage were relatively small both on spatial and temporal dimensions. This study provides strategic information for optimal utilization of water resources in arid and semi-arid river basin.

Verantortlicher Prof: P. Burlando

http://link.springer.com/article/10.1007/s11269-015-1005-zhttp://onlinelibrary.wiley.com/doi/10.1002/hyp.10307/abstract


46) Title Influence of Hydropower Development on Flow Regime in the Zambezi River Basin for Different Scenarios of Environmental Flows

Author(s) Cohen Liechti, T.; Matos, J.P.; Boillat, J.-L.; Schleiss, A.J.; Matos, A.J. Year 2014 Journal Water Resources Management Link http://link.springer.com/article/10.1007/s11269-014-0838-1

Abstract As the need for energy is increasing, the challenges in the future are to operate existing large hydraulic schemes in more sustainable ways and to develop future water resources projects that are able to achieve a better balance between environmental and socio-economic demands. In this context, scenarios combining different levels of environmental requirements as well as hydropower developments were simulated at a daily time step with a hydraulic-hydrological model (the Soil and Water Assessment Tool) over the Zambezi River Basin. For each scenario, the hydropower operation rules, the mean annual energy produced and the firm powers were considered. The impact on the flow regime was characterized by a hydrological alteration indicator and Pardé coefficients. In the present state, the total mean annual energy production is about 30,000 GWh with a firm power of about 3,000 MW. The impact of the dams on the flow regime is low in the Kafue flats and the Zambezi delta and high in the Mana Pools. The new run-of-river hydropower plants aim to increase the mean energy production by more than 90 % and the firm power by about 40 %. Releasing e-flows can reduce the impact in the Kafue flats and in the Zambezi delta, with a loss of less than 10 % of mean annual energy production and about 15 % of the firm power at Itezhi-Tezhi and Cahora Bassa. This reveals that a compromise between energy production and environmental sustainability can be reached.


47) Title Sustainable floodplain management for flood prevention and water quality improvement

Author(s) Kiedrzyńska, Edyta; Kiedrzyński, Marcin; Zalewski, Maciej Year 2015 Journal Natural Hazards Link http://link.springer.com/article/10.1007%2Fs11069-014-1529-1

Abstract Although it is not possible to completely eliminate flooding in an era of climate change and intensification of extreme weather events, effective flood prevention and management in river floodplains may make a significant contribution. The land use characteristics of a catchment and river valley determine, to a great extent, the functioning of a river floodplain, as well as the quantity and size of the flood pulses in the river. The paper is focused on the role played by ecohydrology in flood risk management and water quality. From the ecohydrological perspective, river floodplains are extremely important and capacious ecosystems which, being periodically flooded, absorb flood and pollutant peaks and may minimise the danger of flooding. Increased natural water retention capacity in floodplain areas and the whole basin in the face of progressive climate change is possible through three routes: the modelling of the hydrological budget of the catchment towards the sustainable ecohydrological management of floodplains, the optimal use of existing hydrotechnical infrastructure and the implementation of ecohydrological biotechnologies. Furthermore, with such a holistic perspective, the role of river floodplains is one that also enhances the resilience of the river basin against climate and anthropogenic change, as well as increasing flood safety, improving water quality and increasing its ecosystem services for society.


http://link.springer.com/article/10.1007/s11269-014-0838-1http://link.springer.com/article/10.1007%2Fs11069-014-1529-1


48) Title An ecohydrological approach to conserving urban water through optimized landscape irrigation schedules

Author(s) Volo, Thomas J.; Vivoni, Enrique R.; Ruddell, Benjamin L. Year 2015 Journal Landscape and Urban Planning Link http://www.sciencedirect.com/science/article/pii/S0169204614002229#

Abstract Despite the high percentage of residential water used outdoors, particularly in arid climates, there is a poor understanding of the fate of water used to maintain urban landscapes. Furthermore, opportunities exist for water conservation through improved irrigation schedules that take advantage of seasonal weather patterns and the natural ability of plants to resist water stress. This study uses a calibrated numerical model of soil moisture dynamics with meteorological data to determine irrigation schedules that minimize outdoor water use while maintaining specified levels of plant water stress. Results suggest annual irrigation well below local municipal recommendations, and substantial modifications to recommended schedules. Differences between xeric (low water use, drip irrigators, and gravel cover) and mesic (high water use, sprinklers, and turfgrass) landscaping, with respect to irrigation scheduling, soil water losses, plant water stress, and potential water savings, are presented to improve planning and maintenance of urban landscapes, particularly in water-scarce regions.


49) Title Turnover and Losses of Phosphorus in Swedish Agricultural Soils: Long-Term Changes, Leaching Trends, and Mitigation Measures

Author(s) Lars Bergström et al. Year 2015 Journal Journal of Environmental Quality Link https://dl.sciencesocieties.org/publications/jeq/abstracts/44/2/512

Abstract Transport of phosphorus (P) from agricultural fields to water bodies deteriorates water quality and causes eutrophication. To reduce P losses and optimize P use efficiency by crops, better knowledge is needed of P turnover in soil and the efficiency of best management practices (BMPs). In this review, we examined these issues using results from 10 Swedish long-term soil fertility trials and various studies on subsurface losses of P. The fertility trials are more than 50 years old and consist

seminar umwelting. papervorschläge hs 2015nasa douglas dc-8 (tail no. n817na) cfm56-2-c1 engines...

Documents