Piringer, Gerhard

2016, Piringer, Gerhard, Bauer, Alexander, Gronauer, Andreas, Saylor, Molly K., Stampfel, Angelika, Kral, Iris

1999, Piringer, Gerhard, Bhattacharya, Sanjoy K.

2008, Zhan, Jingjing, Zheng, Tonghua, Piringer, Gerhard, Day, Christopher, McPherson, Gary L., Lu, Yunfeng, Papadopoulos, Kyriakos D., John, Vijay T.

Effective in situ remediation of groundwater requires the successful delivery of reactive iron particles through soil. In this paper we report the transport characteristics of nanoscale zerovalent iron entrapped in porous silica particles and prepared through an aerosol-assisted process. The entrapment of iron nanoparticles into the silica matrix prevents their aggregation while maintaining the particlesʼ reactivity. Furthermore, the silica particles are functionalized with alkyl groups and are extremely efficient in adsorbing dissolved trichloroethylene (TCE). Because of synthesis through the aerosol route, the particles are of the optimal size range (0.1−1 μm) for mobility through sediments. Column and capillary transport experiments confirm that the particles move far more effectively through model soils than commercially available uncoated nanoscale reactive iron particles. Microcapillary experiments indicate that the particles partition to the interface of TCE droplets, further enhancing their potential for dense non-aqueous-phase liquid source-zone remediation.

2022, Medel-Jiménez, Francisco, Piringer, Gerhard, Gronauer, Andreas, Barta, Norbert, Neugschwandtner, Reinhard W., Krexner, Theresa, Kral, Iris

2013, Menardo, Simona, Bauer, Alexander, Theuretzbacher, Franz, Piringer, Gerhard, Nilsen, Paal Jahre, Balsari, Paolo, Pavliska, Oksana, Amon, Thomas

The costs of producing protected vegetables comprise up to 78 % of the total operating costs in greenhouses. These expenses mainly result from energy consumption. Increasing energy efficiency and expanding the use of renewable energy sources are essential for global competitiveness. The aim of this study is to optimize methane production from miscanthus and to evaluate the potential use of miscanthus as a source of electrical energy, heat, and CO2 in vegetable greenhouses. To optimize methane yield, miscanthus was pretreated by steam explosion using different time/temperature combinations. Pretreatment resulted in a more than threefold increase of methane yield from anaerobic digestion (374 lN kgVS−1) compared with untreated miscanthus. Based on technical parameters from two greenhouses (in Northern and Southern Europe), four different energy balances were established. The balances showed that using methane produced by pretreated miscanthus in vegetable greenhouses can enhance the entire process and therefore make it more sustainable.

2010, Sunkara, Bhanukiran, Zhan, Jingjing, He, Jibao, McPherson, Gary L., Piringer, Gerhard, 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.

2008, Zheng, Tonghua, Zhan, Jingjing, He, Jibao, Day, Christopher, Lu, Yunfeng, McPherson, Gary L., Piringer, Gerhard, John, Vijay T.

Spherical silica particles containing nanoscale zerovalent iron were synthesized through an aerosol-assisted process. These particles are effective for groundwater remediation, with the environmentally benign silica particles serving as effective carriers for nanoiron transport. Incorporation of iron into porous sub-micrometer silica particles protects ferromagnetic iron nanoparticles from aggregation and may increase their subsurface mobility. Additionally, the presence of surface silanol groups on silica particles allows control of surface properties via silanol modification using organic functional groups. Aerosolized silica particles with functional alkyl moieties, such as ethyl groups on the surface, clearly adsorb solubilized trichloroethylene (TCE) in water. These materials may therefore act as adsorbents which have coupled reactivity characteristics. The nanoscale iron/silica composite particles with controlled surface properties have the potential to be efficiently applied for in situ source depletion and in the design of permeable reactive barriers.

2023, Gregory L. Rorrer, Krail, Jürgen, Piringer, Gerhard, Roither, Michael

2022, Hörtenhuber, Stefan, Seiringer, Martin, Theurl, Michaela Clarissa, Größbacher, Verena, Piringer, Gerhard, Kral, Iris, Zollitsch, Werner

2009, Zheng, Tonghua, Zhan, Jingjing, He, Jibao, Sunkara, Bhanukiran, Lu, Yunfeng, McPherson, Gary L., Piringer, Gerhard, Kolesnichenko, Vladimir, John, Vijay T.

Spherical silica particles containing nanoscale zero valent iron were synthesized through an aerosol assisted process. These particles are effective for groundwater remediation, with the environmentally benign silica particles serving as effective carriers for nanoiron transport. Incorporation of iron into porous submicron silica particles protects ferromagnetic iron nanoparticles from aggregation and may increase their subsurface mobility. Additionally, the presence of surface silanol groups on silica particles allows control of surface properties via silanol modification using organic functional groups. Aerosolized silica particles with functional alkyl moieties such as ethyl groups on the surface, clearly adsorb solubilized trichloroethylene (TCE) in water. These materials may therefore act as adsorbents which have coupled reactivity characteristics. Transport experiments indicate that these composite particles are in the optimal size range for effective transport through sediments. The nanoscale iron/silica composite particles with controlled surface properties have the potential to be efficiently applied for in-situ source depletion and in the design of permeable reactive barriers.