@article{BuschMeissnerPotthoffetal.2014,
  author    = {Busch, Jan Philip and Meissner, Tobias and Potthoff, Annegret and Oswald, Sascha Eric},
  title     = {Transport of carbon colloid supported nanoscale zero-valent iron in saturated porous media},
  series = {Journal of contaminant hydrology},
  volume    = {164},
  journal   = {Journal of contaminant hydrology},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0169-7722},
  doi       = {10.1016/j.jconhyd.2014.05.006},
  pages     = {25 -- 34},
  year      = {2014},
  abstract  = {Injection of nanoscale zero-valent iron (nZVI) has recently gained great interest as emerging technology for in-situ remediation of chlorinated organic compounds from groundwater systems. Zero-valent iron (ZVI) is able to reduce organic compounds and to render it to less harmful substances. The use of nanoscale particles instead of granular or microscale particles can increase dechlorination rates by-orders of magnitude due to its high surface area. However, classical nZVI appears to be hampered in its environmental application by its limited mobility. One approach is colloid supported transport of nZVI, where the nZVI gets transported by a Mobile colloid. In this study transport properties of activated carbon colloid supported nZVI (c-nZVI; d(50) = 2.4 mu m) are investigated in column tests using columns of 40 cm length, which were filled with porous media. A suspension was pumped through the column under different physicochemical conditions (addition of a polyanionic stabilizer and changes in pH and ionic strength). Highest observed breakthrough was 62\% of the injected concentration in glass beads with addition of stabilizer. Addition of mono- and bivalent salt, e.g. more than 0.5 mM/L CaCl2, can decrease mobility and changes in pH to values below six can inhibit mobility at all. Measurements of colloid sizes and zeta potentials show changes in the mean particle size by a factor of ten and an increase of zeta potential from -62 mV to -80 mV during the transport experiment. However, results suggest potential applicability of c-nZVI under field conditions. (C) 2014 Elsevier B.V. All rights reserved.},
  language  = {en}
}
@article{BuschMeissnerPotthoffetal.2014,
  author    = {Busch, Jan Philip and Meissner, Tobias and Potthoff, Annegret and Oswald, Sascha Eric},
  title     = {Investigations on mobility of carbon colloid supported nanoscale zero-valent iron (nZVI) in a column experiment and a laboratory 2D-aquifer test system},
  series = {Environmental science and pollution research : official organ of the EuCheMS Division for Chemistry and the Environment, EuCheMS DCE},
  volume    = {21},
  journal   = {Environmental science and pollution research : official organ of the EuCheMS Division for Chemistry and the Environment, EuCheMS DCE},
  number    = {18},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0944-1344},
  doi       = {10.1007/s11356-014-3049-7},
  pages     = {10908 -- 10916},
  year      = {2014},
  abstract  = {Nanoscale zero-valent iron (nZVI) has recently gained great interest in the scientific community as in situ reagent for installation of permeable reactive barriers in aquifer systems, since nZVI is highly reactive with chlorinated compounds and may render them to harmless substances. However, nZVI has a high tendency to agglomerate and sediment; therefore it shows very limited transport ranges. One new approach to overcome the limited transport of nZVI in porous media is using a suited carrier colloid. In this study we tested mobility of a carbon colloid supported nZVI particle "Carbo-Iron Colloids" (CIC) with a mean size of 0.63 mu m in a column experiment of 40 cm length and an experiment in a two-dimensional (2D) aquifer test system with dimensions of 110x40x5 cm. Results show a breakthrough maximum of 82 \% of the input concentration in the column experiment and 58 \% in the 2D-aquifer test system. Detected residuals in porous media suggest a strong particle deposition in the first centimeters and few depositions in the porous media in the further travel path. Overall, this suggests a high mobility in porous media which might be a significant enhancement compared to bare or polyanionic stabilized nZVI.},
  language  = {en}
}