Chapter 8
Ferrates as Powerful Oxidants in Water
Treatment Technologies
Libor Machala, Petr Zajíček, Jan Kolařík, Tomáš Mackuľak, and Jan Filip
Abstract Over the past decades, soluble compounds with iron in high oxidation
state(s) (so-called ferrates) have turned out to be a highly promising and “green”
oxidants deployed in water treatment technologies. Ferrates(IV, V, VI) have good
oxidation properties, as indicated by the magnitude of the oxidation-reduction
potential (an acidic reaction with an oxidation-reduction potential of 2.20 V, in the
basic environment it is 0.72 V), making them interesting for oxidation of inorganic
compounds including metals, the decomposition of broad range of organic pollutants
including various types of micropollutants found in wastewater (pesticides, pharmaceuticals, and drugs), and for disinfection. The important advantage of ferrates is
also their minimal environmental load as the reactions result in the formation of
benign iron hydroxides. The only limitation of using ferrates in practice is their
demanding production as well as their instability due to the high electron affinity of
hexavalent iron.
Keywords Iron · High-valent states · Ferrates · Synthesis · Organic pollutants ·
Micropollutants · Pharmaceutical compounds · Heavy metals · Arsenic ·
Coagulation · Disinfection
8.1 Introduction
The occurrences of diverse emerging contaminants (heavy metals, volatile organic
carbons, pesticides, personal care products, pharmaceuticals, organics, illicit drugs,
and pathogenic microbes), particularly in soil and groundwater, have a negative
impact on the environment. Therefore, the contamination of ground and surface
L. Machala · P. Zajíček · J. Kolařík · J. Filip (*)
Regional Centre of Advanced Technologies and Materials, Palacký University Olomouc,
Olomouc, Czech Republic
e-mail: jan.filip@upol.cz
T. Mackuľak
Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food
Technology, Slovak University of Technology, Bratislava, Slovakia
© Springer Nature Switzerland AG 2020
J. Filip et al. (eds.), Advanced Nano-Bio Technologies for Water and Soil Treatment,
Applied Environmental Science and Engineering for a Sustainable Future,
https://doi.org/10.1007/978-3-030-29840-1_8
177
Ferrates as Powerful Oxidants in Water
Treatment Technologies
Libor Machala, Petr Zajíček, Jan Kolařík, Tomáš Mackuľak, and Jan Filip
Abstract Over the past decades, soluble compounds with iron in high oxidation
state(s) (so-called ferrates) have turned out to be a highly promising and “green”
oxidants deployed in water treatment technologies. Ferrates(IV, V, VI) have good
oxidation properties, as indicated by the magnitude of the oxidation-reduction
potential (an acidic reaction with an oxidation-reduction potential of 2.20 V, in the
basic environment it is 0.72 V), making them interesting for oxidation of inorganic
compounds including metals, the decomposition of broad range of organic pollutants
including various types of micropollutants found in wastewater (pesticides, pharmaceuticals, and drugs), and for disinfection. The important advantage of ferrates is
also their minimal environmental load as the reactions result in the formation of
benign iron hydroxides. The only limitation of using ferrates in practice is their
demanding production as well as their instability due to the high electron affinity of
hexavalent iron.
Keywords Iron · High-valent states · Ferrates · Synthesis · Organic pollutants ·
Micropollutants · Pharmaceutical compounds · Heavy metals · Arsenic ·
Coagulation · Disinfection
8.1 Introduction
The occurrences of diverse emerging contaminants (heavy metals, volatile organic
carbons, pesticides, personal care products, pharmaceuticals, organics, illicit drugs,
and pathogenic microbes), particularly in soil and groundwater, have a negative
impact on the environment. Therefore, the contamination of ground and surface
L. Machala · P. Zajíček · J. Kolařík · J. Filip (*)
Regional Centre of Advanced Technologies and Materials, Palacký University Olomouc,
Olomouc, Czech Republic
e-mail: jan.filip@upol.cz
T. Mackuľak
Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food
Technology, Slovak University of Technology, Bratislava, Slovakia
© Springer Nature Switzerland AG 2020
J. Filip et al. (eds.), Advanced Nano-Bio Technologies for Water and Soil Treatment,
Applied Environmental Science and Engineering for a Sustainable Future,
https://doi.org/10.1007/978-3-030-29840-1_8
177