13.7 Conclusion
• The efficiency of the proposed technology for arsenic separation employing
ferrates was proved on a mobile technological unit with a flow of 100 L/h with
two different sources of groundwater ten times exceeding the allowed limit of
arsenic concentration in drinking water. In both cases the final concentration of
arsenic in the remediated water was lower than the detection limit of the analytical
method (<5 μg/L). The optimal dose of ferrate (ENVIFER from NANO IRON,
Czech Republic) for MEZ water was 10 mg/L, for KLU water was 15 mg/L.
• It has been found that the different chemistry of the tested water in MEZ locality
and KLU locality had a major impact on the reaction of ferrates with arsenic,
although the initial concentration of arsenic was the same. With MEZ water, the
most part of arsenic removal was achieved during the first filtration stage; with
KLU water, it was during the last stage. The operating costs for the treatment will
then differ. As a result, proposing a method and the reagent doses only on the
basis of laboratory tests with distilled water cannot prove efficient.
• The water remediated with the proposed technology meets the limits for drinking
water from the microbiological point of view.
• When working with commercial ferrates, it is recommended that Fe(VI) content
as well as presence of heavy metals in the tested products should be checked.
• The presence of phosphates in higher concentrations could be a limitation in
removing arsenic from water.
References
Bielski BHJ, Thomas MJ (1987) Studies of hypervalent iron in aqueous solutions. 1. Radiationinduced reduction of iron(VI) to iron(V) by CO 2
À
. J Am Chem Soc 109(25):7761–7764. https://
doi.org/10.1021/ja00259a026
Czölderová M, Behúl M, Filip J, Zajíček P, Grabic R, Vojs-Staňová A, Gál M, Kerekeš M, Híveš J,
Ryba J, Rybanská M, Brandeburová P, Mackuľak T (2018) 3D printed polyvinyl alcohol ferrate
(VI) capsules: Effective means for the removal of pharmaceuticals and illicit drugs from
wastewater. Chem Eng J 349:269–275. https://doi.org/10.1016/j.cej.2018.05.089
Filip J, Yngard RA, Siskova K, Marusak Z, Ettler V, Sajdl P, Sharma VK, Zboril R (2011)
Mechanisms and efficiency of the simultaneous removal of metals and cyanides by using
ferrate(VI): Crucial roles of nanocrystalline iron(III) oxyhydroxides and metal carbonates.
Chem Eur J 17(36):10097–10105. https://doi.org/10.1002/chem.201100711
Filip J, Kolařík J, Zajíček P, Maršálek B, Stavělová M, Matysíková J, Mackuľak T, Slunský J (2017)
Experiences with ferrate (FeV and FeIV) application: Results from pilot-scale treatment of
drinking surface and waste waters. In: 10th world congress on chemical engineering, Barcelona,
Spain
Kolařík J, Prucek R, Tuček J, Filip J, Sharma VK, Zbořil R (2018) Impact of inorganic ions and
natural organic matter on arsenates removal by ferrate(VI): Understanding a complex effect of
phosphates ions. Water Res 141:357–365. https://doi.org/10.1016/j.watres.2018.05.024
Prucek R, Tuček J, Kolařík J, Filip J, Marušák Z, Sharma VK, Zbořil R (2013) Ferrate(VI)-induced
arsenite and arsenate removal by in situ structural incorporation into magnetic iron(III) oxide
nanoparticles. Environ Sci Technol 47(7):3283–3292. https://doi.org/10.1021/es3042719
13 Field Study IV: Arsenic Removal from Groundwater by Ferrate. . .
313
• The efficiency of the proposed technology for arsenic separation employing
ferrates was proved on a mobile technological unit with a flow of 100 L/h with
two different sources of groundwater ten times exceeding the allowed limit of
arsenic concentration in drinking water. In both cases the final concentration of
arsenic in the remediated water was lower than the detection limit of the analytical
method (<5 μg/L). The optimal dose of ferrate (ENVIFER from NANO IRON,
Czech Republic) for MEZ water was 10 mg/L, for KLU water was 15 mg/L.
• It has been found that the different chemistry of the tested water in MEZ locality
and KLU locality had a major impact on the reaction of ferrates with arsenic,
although the initial concentration of arsenic was the same. With MEZ water, the
most part of arsenic removal was achieved during the first filtration stage; with
KLU water, it was during the last stage. The operating costs for the treatment will
then differ. As a result, proposing a method and the reagent doses only on the
basis of laboratory tests with distilled water cannot prove efficient.
• The water remediated with the proposed technology meets the limits for drinking
water from the microbiological point of view.
• When working with commercial ferrates, it is recommended that Fe(VI) content
as well as presence of heavy metals in the tested products should be checked.
• The presence of phosphates in higher concentrations could be a limitation in
removing arsenic from water.
References
Bielski BHJ, Thomas MJ (1987) Studies of hypervalent iron in aqueous solutions. 1. Radiationinduced reduction of iron(VI) to iron(V) by CO 2
À
. J Am Chem Soc 109(25):7761–7764. https://
doi.org/10.1021/ja00259a026
Czölderová M, Behúl M, Filip J, Zajíček P, Grabic R, Vojs-Staňová A, Gál M, Kerekeš M, Híveš J,
Ryba J, Rybanská M, Brandeburová P, Mackuľak T (2018) 3D printed polyvinyl alcohol ferrate
(VI) capsules: Effective means for the removal of pharmaceuticals and illicit drugs from
wastewater. Chem Eng J 349:269–275. https://doi.org/10.1016/j.cej.2018.05.089
Filip J, Yngard RA, Siskova K, Marusak Z, Ettler V, Sajdl P, Sharma VK, Zboril R (2011)
Mechanisms and efficiency of the simultaneous removal of metals and cyanides by using
ferrate(VI): Crucial roles of nanocrystalline iron(III) oxyhydroxides and metal carbonates.
Chem Eur J 17(36):10097–10105. https://doi.org/10.1002/chem.201100711
Filip J, Kolařík J, Zajíček P, Maršálek B, Stavělová M, Matysíková J, Mackuľak T, Slunský J (2017)
Experiences with ferrate (FeV and FeIV) application: Results from pilot-scale treatment of
drinking surface and waste waters. In: 10th world congress on chemical engineering, Barcelona,
Spain
Kolařík J, Prucek R, Tuček J, Filip J, Sharma VK, Zbořil R (2018) Impact of inorganic ions and
natural organic matter on arsenates removal by ferrate(VI): Understanding a complex effect of
phosphates ions. Water Res 141:357–365. https://doi.org/10.1016/j.watres.2018.05.024
Prucek R, Tuček J, Kolařík J, Filip J, Marušák Z, Sharma VK, Zbořil R (2013) Ferrate(VI)-induced
arsenite and arsenate removal by in situ structural incorporation into magnetic iron(III) oxide
nanoparticles. Environ Sci Technol 47(7):3283–3292. https://doi.org/10.1021/es3042719
13 Field Study IV: Arsenic Removal from Groundwater by Ferrate. . .
313