Research Outputs

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Now showing 1 - 10 of 32
  • Publication
    Reductive dehalogenation of trichloroethylene using aerosol-assisted Fe/Silica particles
    (American Chemical Society, 2008)
    Zhan, Jingjing 
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    Zheng, Tonghua 
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    ;
    Day, Christopher 
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    He, Jibao 
    ;
    McPherson, Gary L. 
    ;
    Lu, Yunfeng 
    ;
    John, Vijay T. 
      38
  • Publication
    Transport and partitioning of functional aerosol nanoparticles for remediation of trichloroethylene
    (AIChE, 2007-11-05)
    Zhan, Jingjing 
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    Zheng, Tonghua 
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    McPherson, Gary L. 
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    Lu, Yunfeng 
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    Papadopoulos, Kyriakos D. 
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    John, Vijay T. 
    Effective in-situ remediation of contaminated groundwater plume requires the successful delivery of reactive iron particles through soil. This study reports the transport characteristics of nanoscale zerovalent iron particles that are encapsulated in porous silica submicron particles through a novel aerosol-assisted technology. These particles resist aggregation characteristics that are typical of nanoscale zerovalent iron, and are highly reactive. They can be transported through model soils (Ottawa sands) more efficiently than commercially available reactive nanoscale iron particle (RNIP). To explore the fate of particles in sands, macroscopic and microscopic methods were used. Glass burette columns in vertical and horizontal configurations were used to simulate in-situ injection and natural groundwater situations, respectively. In both cases, the composite particles elute readily while RNIP is trapped at the inlet of the column. Capillary experiments further prove that RNIP clogs the pores between sand grains due to rapid aggregation, but pore plugging does not occur for the composite particles. The partitioning characteristic of the particles was investigated by a novel capillary video microscopy technique. Our results again indicate that the iron/silica composite nanparticles preferentially accumulate and localize at the TCE/water interface, making dechlorination more efficient. Such particles with enhanced mobility hold promise in new technologies for in-situ ground water remediation.
      37
  • Publication
    Precision Grassland Farming - Ein überblick über Forschung und Technik
    (Gesellschaft für Informatik e.V., 2017)
    Bauerdick, Josef 
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    Gronauer, Andreas 
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    Kral, Iris 
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    Bernhardt, Heinz 
    Precision Farming ist im Ackerbau ein weithin geläufiger Begriff. Firmen und Forschungseinrichtungen veröffentlichen regelmäßig (informations-)technologische Neuheiten. Trotz des großen Potentials hinsichtlich Ressourceneinsparung und der Überwachung des Bestands, ist festzustellen, dass Precision Farming Applikationen im Grünland bisher kaum zur Anwendung kommen. Der Beitrag soll ein Überblick über bereits vorhandene Precision Farming Anwendungen im Grünland geben, wobei die vollständige Ernteprozesskette hinsichtlich vorhandener Präzisionstechnologie beschrieben wird. Es ist festzustellen, dass vor allem Maschinen, welche sowohl im Ackerbau, als auch im Grünland genutzt werden können, einen hohen Grad der Technisierung hinsichtlich Precision Farming aufweisen. Geräte, welche jedoch ausschließlich im Grünland genutzt werden, weisen nur geringe Tendenzen in diesem Bereich auf. Häufig wurden diese lediglich zu Forschungszwecken entwickelt und kaum in die Praxis überführt. Künftig sind Forschungen, vor allem, um Bröckelverluste zu minimieren, durchzuführen.
      61
  • Publication
    Delivery and targeting of functional aerosol particle in DNAPL remediation
    (American Chemical Society, 2008)
    Zhan, Jingjing 
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    Day, Christopher 
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    ;
    McPherson, Gary L. 
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    Lu, Yunfeng 
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    Papadopoulos, Kyriakos D. 
    ;
    John, Vijay T. 
      47
  • Publication
    Trichloroethylene remediation using nanoscale iron/silica aerosol particles
    (American Chemical Society, 2007)
    Zheng, Tonghua 
    ;
    Zhan, Jingjing 
    ;
    He, Jibao 
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    ;
    McPherson, Gary L. 
    ;
    Lu, Yunfeng 
    ;
    John, Vijay T. 
      44
  • Publication
    Potential of different Sorghum bicolor (L. moench) varieties for combined ethanol and biogas production in the Pannonian climate of Austria
    (Elsevier, 2013)
    Theuretzbacher, Franz 
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    Bauer, Alexander 
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    Lizasoain, Javier 
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    Becker, Manuel 
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    Rosenau, Thomas 
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    Potthast, Antje 
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    Friedl, Anton 
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    Gronauer, Andreas 
    The objective of this study is to estimate the energetic yields of a combined ethanol and biogas production from three different sorghum varieties, and to compare them to a similar estimate for maize in order to demonstrate the suitability of sorghum as an alternative biomass source. The sorghum varieties “SG1” (Sugargraze I) and “SG2” (Sugargraze II), which produce fermentable sugars, as well as the grain variety “C” (Chopper), which produces starch, were grown on experimental plots in eastern Austria. The harvested biomass was analysed for its contents of cellulose, hemicellulose, lignin, crude protein, crude fats, starch and sugar. For the calculation of the energy output, ethanol and biogas yields were calculated corresponding to accepted standard methods. The potential of sorghum for energy production has been demonstrated. The highest energy outputs were achieved by the SG1 and the C varieties, delivering approximately 150 GJ ha−1 and 156 GJ ha−1. Compared to data obtained from different maize varieties in the same year and under similar conditions, this means an equal or even increased energy output per hectare. The SG2 variety only yielded 121 GJ ha−1 worth of ethanol and biogas. Bioethanol and biogas production were unequally distributed between sugar and starch varieties: SG1 provided 70% of its energy output as methane and the rest as bioethanol, whereas the grain variety C yielded 46% methane and 54% bioethanol.
      62Scopus© Citations 14
  • Publication
    Nanoscale zerovalent iron supported on uniform carbon microspheres for the in situ remediation of chlorinated hydrocarbons
    (American Chemical Society, 2010)
    Sunkara, Bhanukiran 
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    Zhan, Jingjing 
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    He, Jibao 
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    McPherson, Gary L. 
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    ;
    John, Vijay T. 
    Nanoscale zerovalent iron particles (NZVI) are a preferred option for reductive dehalogenation of dense nonaqueous phase chlorinated hydrocarbons such as trichloroethylene (TCE) because of their environmentally benign nature, high efficiency, and low cost. This study describes an approach to engineered particles containing NZVI that are effective targeted delivery agents for the remediation of these compounds. The particles contain highly uniform carbon microspheres embedded with NZVI (Fe0/C composite particles). The highly adsorptive carbon keeps the TCE in the proximity of the reactive sites and serves as a sorptive sink for TCE removal. The Fe0/C composite particles are in the optimal size range for transport through soil and the polyelectrolyte (Carboxymethyl cellulose, CMC) is used to stabilize the composite microspheres in aqueous solution. The multiple functionalities associated with these particles can be designed at low cost and the materials are environmentally benign.
      47Scopus© Citations 84
  • Publication
    Implementing an advanced waste separation step in an MBT plant: assessment of technical, economic and environmental impacts
    Heavy fractions resulting from mechanical treatment stages of mechanical–biological waste treatment plants are posing very specific demands with regard to further treatment (large portions of inert and high-caloric components). Based on the current Austrian legal situation such a waste stream cannot be landfilled and must be thermally treated. The aim of this research was to evaluate if an inert fraction generated from this waste stream with advanced separation technologies, two sensor-based [near-infrared spectroscopy (NIR), X-ray transmission (XRT)] and two mechanical systems (wet and dry) is able to be disposed of. The performance of the treatment options for separation was evaluated by characterizing the resulting product streams with respect to purity and yield. Complementing the technical evaluation of the processing options, an assessment of the economic and global warming effects of the change in waste stream routing was conducted. The separated inert fraction was evaluated with regard to landfilling. The remaining high-caloric product stream was evaluated with regard to thermal utilization. The results show that, in principal, the selected treatment technologies can be used to separate high-caloric from inert components. Limitations were identified with regard to the product qualities achieved, as well as to the economic expedience of the treatment options. One of the sensor-based sorting systems (X-ray) was able to produce the highest amount of disposeable heavy fraction (44.1%), while having the lowest content of organic (2.0% Cbiogenic per kg waste input) components. None of the high-caloric product streams complied with the requirements for solid recovered fuels as defined in the Austrian Ordinance on Waste Incineration. The economic evaluation illustrates the highest specific treatment costs for the XRT (€23.15 per t), followed by the NIR-based sorting system (€15.67 per t), and the lowest costs for the air separation system (€10.79 per t). Within the ecological evaluation it can be shown that the results depend strongly on the higher heating value of the high caloric light fraction and on the content of Cbiogenic of the heavy fraction. Therefore, the XRT system had the best results for the overall GWP [−14 kg carbon dioxide equivalents (CO2eq) per t of input waste] and the NIR-based the worst (193 kg CO2 eq per t of input waste). It is concluded that three of the treatment options would be suitable under the specific conditions considered here. Of these, sensor-based sorting is preferable owing to its flexibility.
    Scopus© Citations 2  177
  • Publication
    Life Cycle Assessment of Biogas Production from Unused Grassland Biomass Pretreated by Steam Explosion Using a System Expansion Method
    (MDPI, 2020)
    Kral, Iris 
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    Saylor, Molly K. 
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    Lizasoain, Javier 
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    Gronauer, Andreas 
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    Bauer, Alexander 
    Reforestation is a threat to permanent grasslands in many alpine regions. Using these areas to produce biogas energy may help to preserve these important landscapes and save fossil fuels by adding a renewable local heat and electricity source. This case study compares (a) a status quo (SQ) reference scenario with heating oil, wood-chips, and grid electricity as municipal energy sources, and (b) a hypothetical local biogas (LB) scenario (to also be used as a municipal energy source) based on a 500-kWel biogas plant with steam explosion pretreatment. Here, hay from previously unused grassland is the main biogas substrate, whereas, in the reference SQ scenario, these grasslands remain unused. Life cycle assessment (LCA) results for LB and SQ scenarios are significantly different at p < 0.05 in all six impact categories. In three categories, the LB scenario has lower impacts than the SQ scenario, including climate change (0.367 CO2-eq kWhel-1 versus 0.501 CO2-eq kWhel-1). Dominant contributions to climate change in the SQ scenario are from the extant municipal energy sources that the LB biogas plant would replace; in the LB scenario, important contributions include unburned methane from the biogas plant, as well as CO2 emissions from hay production machines. In summary, important environmental impacts can be reduced and alpine grasslands can be preserved by biogas production from that grass. The advantages of integrating a local biogas plant in municipal energy and waste systems depend strongly on the extant municipal energy system characteristics.
      140Scopus© Citations 6
  • Publication
    Market development and consequences on end-of-life management of photovoltaic implementation in Europe
    (2020) ;
    Franz, Manuela 
    Abstract Background The 2018 European Renewables Directive sets a binding target of 32% of renewable energy generation by 2030. Free-field photovoltaic plants are characterised by significant land use and material flows. Although country-level data on installed power is available, information about the spatial distribution of PV plants is rare. When the first photovoltaic systems will reach their end-of-life on a large scale in 2035, economic, technological and ecological challenges will arise. Methods The study explores the market development of photovoltaic power in the EU countries from 2008 to 2017 by preparing statistical data and Google mapping of free-field PV plants. Different approaches to assessing the land use of free-field PV systems compared to other energy systems are investigated. A comprehensive literature review addresses key issues of PV module waste treatment, hazardous constituents and their leakage in case of module breakage as well as financial issues of decommissioning and recycling and re-use of used modules. Results Most of the European PV electrical energy is generated by approximately 17,000 widely distributed free-field plants predominantly installed in lowlands. A local in-depth study shows that roof-top plants contribute less than 5% to the total PV energy generation in an area without extensive expansion to industrial buildings. Small amounts of hazardous substances that are typically present in PV modules are unlikely to affect the environment during normal operation of the system, but the question of leakage from broken end-of-life modules is not sufficiently clarified. While in the EU, the recycling and disposal costs are covered by producer fees and expected raw material profits; the financing of the decommissioning of thousands of PV free-field plants is still an open issue. Conclusions The land use of free-field PV systems should be analysed in more detail. Concerning hazardous substances, there seems to be an emerging consensus in literature that the leaching behaviour of metals from broken PV module pieces is inadequately simulated by current waste characterisation protocols. It is recommended to pay greater attention to financing the decommissioning of free-field commercial and industrial scale PV systems.
      1Scopus© Citations 6