interesting genus found in the sediment samples was Dehalococcoides, which is a
typical representative of chlororespiring bacteria. After the whey circulation period,
an increase in vcrA gene copies was recorded, which greatly corresponded to an
increase in the detected degradation products of chlorinated ethenes and to a
decreasing chlorine number.
20.4 Conclusion
The results of the two presented pilot tests clearly demonstrate the potential of nZVI
for nano-bioremediation application of sites with Cr(VI) contamination via
geofixation of the metal into the soil. The decrease in contamination after the
nZVI application and the closely connected improvement of the living conditions
for microbial species (e.g., lower toxicity, ORP) facilitated the implementation of the
next bioremediation step. The subsequent injection of the inexpensive organic
substrate caused an increase in the microbial biomass, which was consequently
able to continue with reduction of chromium or transformation of TCE even after
complete oxidation of nZVI. Both studies document the feasibility and high efficiency of the combination of nanotechnology and biotechnology in remediation of
chromium-contaminated sites with a clearly long-term effect.
References
Mueller NC, Braun J, Bruns J, Černík M, Rissing P, Rickerby D, Nowack B (2012) Application of
nanoscale zero valent iron (NZVI) for groundwater remediation in Europe. Environ Sci Pollut
Res 19(2):550–558. https://doi.org/10.1007/s11356-011-0576-3
Němeček J, Lhotský O, Cajthaml T (2014) Nanoscale zero-valent iron application for in situ
reduction of hexavalent chromium and its effects on indigenous microorganism populations.
Sci Total Environ 485–486:739–747. https://doi.org/10.1016/j.scitotenv.2013.11.105
Němeček J, Pokorný P, Lacinová L, Černík M, Masopustová Z, Lhotský O, Filipová A, Cajthaml T
(2015) Combined abiotic and biotic in-situ reduction of hexavalent chromium in groundwater
using nZVI and whey: a remedial pilot test. J Hazard Mater 300:670–679. https://doi.org/10.
1016/j.jhazmat.2015.07.056
Němeček J, Pokorný P, Lhotský O, Knytl V, Najmanová P, Steinová J, Černík M, Filipová A,
Filip J, Cajthaml T (2016) Combined nano-biotechnology for in-situ remediation of mixed
contamination of groundwater by hexavalent chromium and chlorinated solvents. Sci Total
Environ 563–564:822–834. https://doi.org/10.1016/j.scitotenv.2016.01.019
Semerád J, Cajthaml T (2016) Ecotoxicity and environmental safety related to nano-scale
zerovalent iron remediation applications. Appl Microbiol Biotechnol 100(23):9809–9819.
https://doi.org/10.1007/s00253-016-7901-1
Semerád J, Čvančarová M, Filip J, Kašlík J, Zlotá J, Soukupová J, Cajthaml T (2018) Novel assay
for the toxicity evaluation of nanoscale zero-valent iron and derived nanomaterials based on
lipid peroxidation in bacterial species. Chemosphere 213:568–577. https://doi.org/10.1016/j.
chemosphere.2018.09.029
20 Nano-Bioremediation: Nanoscale Zero-Valent Iron for Inorganic and. . .
433
typical representative of chlororespiring bacteria. After the whey circulation period,
an increase in vcrA gene copies was recorded, which greatly corresponded to an
increase in the detected degradation products of chlorinated ethenes and to a
decreasing chlorine number.
20.4 Conclusion
The results of the two presented pilot tests clearly demonstrate the potential of nZVI
for nano-bioremediation application of sites with Cr(VI) contamination via
geofixation of the metal into the soil. The decrease in contamination after the
nZVI application and the closely connected improvement of the living conditions
for microbial species (e.g., lower toxicity, ORP) facilitated the implementation of the
next bioremediation step. The subsequent injection of the inexpensive organic
substrate caused an increase in the microbial biomass, which was consequently
able to continue with reduction of chromium or transformation of TCE even after
complete oxidation of nZVI. Both studies document the feasibility and high efficiency of the combination of nanotechnology and biotechnology in remediation of
chromium-contaminated sites with a clearly long-term effect.
References
Mueller NC, Braun J, Bruns J, Černík M, Rissing P, Rickerby D, Nowack B (2012) Application of
nanoscale zero valent iron (NZVI) for groundwater remediation in Europe. Environ Sci Pollut
Res 19(2):550–558. https://doi.org/10.1007/s11356-011-0576-3
Němeček J, Lhotský O, Cajthaml T (2014) Nanoscale zero-valent iron application for in situ
reduction of hexavalent chromium and its effects on indigenous microorganism populations.
Sci Total Environ 485–486:739–747. https://doi.org/10.1016/j.scitotenv.2013.11.105
Němeček J, Pokorný P, Lacinová L, Černík M, Masopustová Z, Lhotský O, Filipová A, Cajthaml T
(2015) Combined abiotic and biotic in-situ reduction of hexavalent chromium in groundwater
using nZVI and whey: a remedial pilot test. J Hazard Mater 300:670–679. https://doi.org/10.
1016/j.jhazmat.2015.07.056
Němeček J, Pokorný P, Lhotský O, Knytl V, Najmanová P, Steinová J, Černík M, Filipová A,
Filip J, Cajthaml T (2016) Combined nano-biotechnology for in-situ remediation of mixed
contamination of groundwater by hexavalent chromium and chlorinated solvents. Sci Total
Environ 563–564:822–834. https://doi.org/10.1016/j.scitotenv.2016.01.019
Semerád J, Cajthaml T (2016) Ecotoxicity and environmental safety related to nano-scale
zerovalent iron remediation applications. Appl Microbiol Biotechnol 100(23):9809–9819.
https://doi.org/10.1007/s00253-016-7901-1
Semerád J, Čvančarová M, Filip J, Kašlík J, Zlotá J, Soukupová J, Cajthaml T (2018) Novel assay
for the toxicity evaluation of nanoscale zero-valent iron and derived nanomaterials based on
lipid peroxidation in bacterial species. Chemosphere 213:568–577. https://doi.org/10.1016/j.
chemosphere.2018.09.029
20 Nano-Bioremediation: Nanoscale Zero-Valent Iron for Inorganic and. . .
433