undesirable reactions of nZVI with dissolved oxygen and nitrates were identified as
contributing to Fe(0) consumption to a large extent. The reactive lifetime of the
nanoparticles at the site was found to be at least 103 days but some residual Fe
(0) was proved to be present on site even after 165 days.
Not only were pilot trials on the in situ groundwater remediation reported, but
also the usage of nZVI for waste water treatment was documented. A Slovenian
research team investigated the effects of different nZVI particles (NANOFER
25, NANOFER STAR and borohydride-nZVI) on metal, bacteria and content of
nitrogen in a real effluent water from a small biological wastewater treatment plant
(Oprčkal et al. 2017). This work showed that there can be a risk of releasing trace
elements into the water if these are bound to nZVI particles. Therefore, careful
optimization of the iron load, and of the mixing and settling times, is necessary for
the efficient process optimization. Despite in-house nZVI being the most efficient at
inactivating pathogenic bacteria, these nanoparticles are not appropriate for remediation since it was found that the high levels of B and Na, originating from the NaBH 4
used for their synthesis, contaminated the remediated water. The NANOFER
25 slurry most effectively removed potentially toxic elements and at optimal mixing
and settling times (400 and 180 min, respectively) effectively disinfected effluent
water at a low (0.5 g/L) iron load.
In another study, a full-scale application of nZVI for heavy metal removal from
waste water of the Jiangxi Copper Company, China, has been reported (Li et al.
2017). The waste water was contaminated predominantly with Cu, Ni, Zn, Pb, As, Se
and Sb. Borohydride-reduced nZVI was applied in 5 m  5 m  3 m separated
modules connected to the existing waste water treatment plant. The performance of
the technology over 120 days proved that nZVI acted as a highly efficient reagent
(>99.5% removal of key metals with capacities of 245 mg and 226 mg of As and Cu
per 1 g of nZVI, respectively) providing a low redox potential and subsequent
separation of metals. The advantage of such a technology lies in the fact that nZVI
keeps a low redox condition in the closed reactors, lowering the required nZVI
demand over time (>12 months) with partial recycling of nZVI.
References
Ahn J-Y, Kim C, Kim H-S, Hwang K-Y, Hwang I (2016) Effects of oxidants on in situ treatment of
a DNAPL source by nanoscale zero-valent iron: a field study. Water Res 107:57–65. https://doi.
org/10.1016/j.watres.2016.10.037
Alessi DS, Li Z (2001) Synergistic effect of cationic surfactants on perchloroethylene degradation
by zero-valent iron. Environ Sci Technol 35(18):3713–3717. https://doi.org/10.1021/es010564i
Applegate JS, Laitos JG (2006) Environmental law: RCRA, CERCLA, and the management of
hazardous waste. Foundation Press, New York
Bard AJ, Parsons R, Jordan J (eds) (1985) Standard potentials in aqueous solution, 1st edn. CRC
Press, New York
Bardos P, Merly C, Kvapil P, Koschitzky H-P (2018) Status of nanoremediation and its potential for
future deployment: risk-benefit and benchmarking appraisals. Remediat J 28(3):43–56. https://
doi.org/10.1002/rem.21559
44
T. Phenrat et al.
contributing to Fe(0) consumption to a large extent. The reactive lifetime of the
nanoparticles at the site was found to be at least 103 days but some residual Fe
(0) was proved to be present on site even after 165 days.
Not only were pilot trials on the in situ groundwater remediation reported, but
also the usage of nZVI for waste water treatment was documented. A Slovenian
research team investigated the effects of different nZVI particles (NANOFER
25, NANOFER STAR and borohydride-nZVI) on metal, bacteria and content of
nitrogen in a real effluent water from a small biological wastewater treatment plant
(Oprčkal et al. 2017). This work showed that there can be a risk of releasing trace
elements into the water if these are bound to nZVI particles. Therefore, careful
optimization of the iron load, and of the mixing and settling times, is necessary for
the efficient process optimization. Despite in-house nZVI being the most efficient at
inactivating pathogenic bacteria, these nanoparticles are not appropriate for remediation since it was found that the high levels of B and Na, originating from the NaBH 4
used for their synthesis, contaminated the remediated water. The NANOFER
25 slurry most effectively removed potentially toxic elements and at optimal mixing
and settling times (400 and 180 min, respectively) effectively disinfected effluent
water at a low (0.5 g/L) iron load.
In another study, a full-scale application of nZVI for heavy metal removal from
waste water of the Jiangxi Copper Company, China, has been reported (Li et al.
2017). The waste water was contaminated predominantly with Cu, Ni, Zn, Pb, As, Se
and Sb. Borohydride-reduced nZVI was applied in 5 m  5 m  3 m separated
modules connected to the existing waste water treatment plant. The performance of
the technology over 120 days proved that nZVI acted as a highly efficient reagent
(>99.5% removal of key metals with capacities of 245 mg and 226 mg of As and Cu
per 1 g of nZVI, respectively) providing a low redox potential and subsequent
separation of metals. The advantage of such a technology lies in the fact that nZVI
keeps a low redox condition in the closed reactors, lowering the required nZVI
demand over time (>12 months) with partial recycling of nZVI.
References
Ahn J-Y, Kim C, Kim H-S, Hwang K-Y, Hwang I (2016) Effects of oxidants on in situ treatment of
a DNAPL source by nanoscale zero-valent iron: a field study. Water Res 107:57–65. https://doi.
org/10.1016/j.watres.2016.10.037
Alessi DS, Li Z (2001) Synergistic effect of cationic surfactants on perchloroethylene degradation
by zero-valent iron. Environ Sci Technol 35(18):3713–3717. https://doi.org/10.1021/es010564i
Applegate JS, Laitos JG (2006) Environmental law: RCRA, CERCLA, and the management of
hazardous waste. Foundation Press, New York
Bard AJ, Parsons R, Jordan J (eds) (1985) Standard potentials in aqueous solution, 1st edn. CRC
Press, New York
Bardos P, Merly C, Kvapil P, Koschitzky H-P (2018) Status of nanoremediation and its potential for
future deployment: risk-benefit and benchmarking appraisals. Remediat J 28(3):43–56. https://
doi.org/10.1002/rem.21559
44
T. Phenrat et al.