Piringer, Gerhard

Thumbnail Image
Official Name
Piringer, Gerhard
Main Affiliation
Akademische Titel
DI, Ph.D.
Email
gerhard.piringer@fh-burgenland.at
ORCID
Scopus Author ID
23095387800
Status
staff

Research Outputs

2011 2011 2010 2010 2009 2009 2008 2008 2007 2007 0.0 0.0 0.5 0.5 1.0 1.0 1.5 1.5 2.0 2.0 2.5 2.5 3.0 3.0 3.5 3.5 4.0 4.0

Filters

11
Reset filters

Settings

Now showing 1 - 10 of 11
  • No Thumbnail Available
    Publication
    Delivery and targeting of functional aerosol particle in DNAPL remediation
    (American Chemical Society, 2008)
    Zhan, Jingjing 
    ;
    Day, Christopher 
    ;
    Piringer, Gerhard 
    ;
    McPherson, Gary L. 
    ;
    Lu, Yunfeng 
    ;
    Papadopoulos, Kyriakos D. 
    ;
    John, Vijay T. 
      49  1
  • No Thumbnail Available
    Publication
    Nanoscale zerovalent iron supported on uniform carbon microspheres for the in situ remediation of chlorinated hydrocarbons
    (American Chemical Society, 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.
      48  1Scopus© Citations 86
  • No Thumbnail Available
    Publication
    Transport and partitioning of functional aerosol nanoparticles for remediation of trichloroethylene
    (AIChE, 2007-11-05)
    Zhan, Jingjing 
    ;
    Zheng, Tonghua 
    ;
    Piringer, Gerhard 
    ;
    McPherson, Gary L. 
    ;
    Lu, Yunfeng 
    ;
    Papadopoulos, Kyriakos D. 
    ;
    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.
      39  1
  • No Thumbnail Available
    Publication
    Aerosol-assisted nanoscale Fe/silica particles for dechlorination of trichloroethylene
    (AIChE, 2007-11-07)
    Zheng, Tonghua 
    ;
    Zhan, Jingjing 
    ;
    Piringer, Gerhard 
    ;
    McPherson, Gary L. 
    ;
    Lu, Yunfeng 
    ;
    John, Vijay T. 
    Nanoscale iron particles are a preferred option for the reductive dehalogenation of trichloroethylene (TCE) due to their environmentally benign nature, high efficiency and low cost. However, nanoscale zerovalent iron (ZVI) particles aggregate and in in-situ remediation technologies, it is difficult to transport these particles to the source of contamination. This study describes a novel approach to the preparation of ZVI nanoparticles that are efficient and effectively transport to contaminant sites. We describe the synthesis of silica supported iron nanoparticles using aerosol technology. While the encapsulated iron nanoparticles are reactive for groundwater trichloroethylene remediation, environmentally benign silica particles serve as effective carriers for nanoiron transport through soil. Encapsulation of iron into submicron silica particles protects ferromagnetic iron nanoparticles from aggregation and may increase their mobility through sedimentation. Additionally, the presence of surface silanol groups on silica particles allows control of surface properties via silanol modification using organic functional groups. Aerosol silica particles with functional groups such as ethyl tails on the surface preferentially adsorb hydrophobic TCE during environmental remediation. This increases the local concentration of TCE in the vicinity of iron nanoparticles, thus promoting the degradation of TCE by iron. These nanoscale iron/silica aerosol particles with controlled surface properties have the potential to be efficiently applied for in-situ remediation and permeable reactive barriers construction.
      58  1
  • No Thumbnail Available
    Publication
    Nanostructured multifunctional materials for environmental remediation of chlorinated hydrocarbons
    (American Chemical Society, 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.
      53  1Scopus© Citations 3
  • No Thumbnail Available
    Publication
    Multifunctional iron-carbon nanocomposites through an aerosol-based process for the in situ remediation of chlorinated hydrocarbons
    (American Chemical Society, 2011)
    Zhan, Jingjing 
    ;
    Kolesnichenko, Igor 
    ;
    Sunkara, Bhanukiran 
    ;
    He, Jibao 
    ;
    McPherson, Gary L. 
    ;
    Piringer, Gerhard 
    ;
    John, Vijay T. 
    Spherical iron-carbon nanocomposites were developed through a facile aerosol-based process with sucrose and iron chloride as starting materials. These composites exhibit multiple functionalities relevant to the in situ remediation of chlorinated hydrocarbons such as trichloroethylene (TCE). The distribution and immobilization of iron nanoparticles on the surface of carbon spheres prevents zerovalent nanoiron aggregation with maintenance of reactivity. The aerosol-based carbon microspheres allow adsorption of TCE, thus removing dissolved TCE rapidly and facilitating reaction by increasing the local concentration of TCE in the vicinity of iron nanoparticles. The strongly adsorptive property of the composites may also prevent release of any toxic chlorinated intermediate products. The composite particles are in the optimal range for transport through groundwater saturated sediments. Furthermore, those iron-carbon composites can be designed at low cost, the process is amenable to scale-up for in situ application, and the materials are intrinsically benign to the environment.
      52  1Scopus© Citations 74
  • No Thumbnail Available
    Publication
    Reactivity characteristics of nanoscale zerovalent iron-silica composites for trichloroethylene remediation
    (American Chemical Society, 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.
      40  1Scopus© Citations 137
  • No Thumbnail Available
    Publication
    Reductive dehalogenation of trichloroethylene using aerosol-assisted Fe/Silica particles
    (American Chemical Society, 2008)
    Zhan, Jingjing 
    ;
    Zheng, Tonghua 
    ;
    Piringer, Gerhard 
    ;
    Day, Christopher 
    ;
    He, Jibao 
    ;
    McPherson, Gary L. 
    ;
    Lu, Yunfeng 
    ;
    John, Vijay T. 
      38  1
  • No Thumbnail Available
    Publication
    Trichloroethylene remediation using nanoscale iron/silica aerosol particles
    (American Chemical Society, 2007)
    Zheng, Tonghua 
    ;
    Zhan, Jingjing 
    ;
    He, Jibao 
    ;
    Piringer, Gerhard 
    ;
    McPherson, Gary L. 
    ;
    Lu, Yunfeng 
    ;
    John, Vijay T. 
      44  1
  • No Thumbnail Available
    Publication
    Multifunctional colloidal particles for in situ remediation of chlorinated hydrocarbons
    (American Chemical Society, 2009)
    Zhan, Jingjing 
    ;
    Sunkara, Bhanukiran 
    ;
    Le, Lynn 
    ;
    John, Vijay T. 
    ;
    He, Jibao 
    ;
    McPherson, Gary L. 
    ;
    Piringer, Gerhard 
    ;
    Lu, Yunfeng 
    Effective in situ injection technology for the remediation of dense nonaqueous phase liquids (DNAPLs) such as trichloroethylene (TCE) requires the use of decontamination agents that effectively migrate through the soil media and react efficiently with dissolved TCE and bulk TCE. We describe the use of a novel decontamination system containing highly uniform carbon microspheres in the optimal size range for transport through the soil. The microspheres are enveloped in a polyelectrolyte (carboxymethyl cellulose, CMC) to which a bimetallic nanoparticle system of zero-valent iron and Pd is attached. The carbon serves as a strong adsorbent to TCE, while the bimetallic nanoparticle system provides the reactive component. The polyelectrolyte serves to stabilize the carbon microspheres in aqueous solution. The overall system resembles a colloidal micelle with a hydrophilic shell (polyelectrolyte coating) and hard hydrophobic core (carbon). In contact with bulk TCE, there is a sharp partitioning of the system to the TCE side of the interface due to the hydrophobicity of the core. These multifunctional systems appear to satisfy criteria related to remediation and are made with potentially environmentally benign materials.
      51  1Scopus© Citations 53