TY  - JOUR
A1  - Busch, Jan Philip
A1  - Meissner, Tobias
A1  - Potthoff, Annegret
A1  - Oswald, Sascha Eric
T1  - Transport of carbon colloid supported nanoscale zero-valent iron in saturated porous media
JF  - Journal of contaminant hydrology
N2  - 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.
KW  - Nanoscale zero-valent iron (nZVI)
KW  - Nanomaterial
KW  - Carbo-Iron (R)
KW  - Colloid transport
KW  - Mobility
KW  - In-situ remediation
Y1  - 2014
U6  - https://doi.org/10.1016/j.jconhyd.2014.05.006
SN  - 0169-7722
SN  - 1873-6009
VL  - 164
SP  - 25
EP  - 34
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Busch, Jan Philip
A1  - Meissner, Tobias
A1  - Potthoff, Annegret
A1  - Oswald, Sascha Eric
T1  - Investigations on mobility of carbon colloid supported nanoscale zero-valent iron (nZVI) in a column experiment and a laboratory 2D-aquifer test system
JF  - Environmental science and pollution research : official organ of the EuCheMS Division for Chemistry and the Environment, EuCheMS DCE
N2  - 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.
KW  - Carbon colloid
KW  - Nanoscale zero-valent iron (nZVI)
KW  - Aquifer systems
Y1  - 2014
U6  - https://doi.org/10.1007/s11356-014-3049-7
SN  - 0944-1344
SN  - 1614-7499
VL  - 21
IS  - 18
SP  - 10908
EP  - 10916
PB  - Springer
CY  - Heidelberg
ER  -