Chapter 3
Other Chemical Reductive Methods
Jan Němeček, Stanisław Wacławek, and Miroslav Černík
Abstract Chromium is used ubiquitously in various industrial applications as it has
several advantages. It can provide, e.g., a robust and rust-resistant coating for various
materials. However, the most dangerous form—chromium(VI)—is soluble in water
and therefore can trigger numerous health problems. One of the most common ways to
remediate Cr(VI) is to reduce it to a less toxic and mobile form, i.e., chromium(III).
This can be achieved in different ways; nevertheless, this chapter will mainly cover the
in situ reduction of Cr(VI) with sulfur compounds. Two sites contaminated with
Cr(VI) will be presented, and actions related to their decontamination will be
described. The design of the planned techniques will be assessed, in the bench-scale
studies first. Afterwards remediation in the field scale will be shown as a model
example of how to manage and operate remedial interventions for sites contaminated
with Cr(VI) based on the in situ reduction with the sulfur compounds.
Keywords In situ methods · Sulfur compounds · Chromium(VI) · In situ chemical
reduction (ISCR)
3.1 Introduction
In general, in situ chemical reduction (ISCR) is a method based on chemical
reduction of selected contaminants by a reagent, used as a source of electrons.
Besides zero-valent iron, discussed elsewhere, the most commonly used reagents
are dissolved sulfur compounds in different oxidation states: sulfides S(–II) are
represented by sodium hydrosulfide (NaHS), polysulfides S x (–II) by calcium
J. Němeček · S. Wacławek
Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of
Liberec, Liberec, Czech Republic
M. Černík (*)
Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of
Liberec, Liberec, Czech Republic
AQUATEST a.s., Prague, Czech Republic
e-mail: miroslav.cernik@tul.cz
© 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_3
53
Other Chemical Reductive Methods
Jan Němeček, Stanisław Wacławek, and Miroslav Černík
Abstract Chromium is used ubiquitously in various industrial applications as it has
several advantages. It can provide, e.g., a robust and rust-resistant coating for various
materials. However, the most dangerous form—chromium(VI)—is soluble in water
and therefore can trigger numerous health problems. One of the most common ways to
remediate Cr(VI) is to reduce it to a less toxic and mobile form, i.e., chromium(III).
This can be achieved in different ways; nevertheless, this chapter will mainly cover the
in situ reduction of Cr(VI) with sulfur compounds. Two sites contaminated with
Cr(VI) will be presented, and actions related to their decontamination will be
described. The design of the planned techniques will be assessed, in the bench-scale
studies first. Afterwards remediation in the field scale will be shown as a model
example of how to manage and operate remedial interventions for sites contaminated
with Cr(VI) based on the in situ reduction with the sulfur compounds.
Keywords In situ methods · Sulfur compounds · Chromium(VI) · In situ chemical
reduction (ISCR)
3.1 Introduction
In general, in situ chemical reduction (ISCR) is a method based on chemical
reduction of selected contaminants by a reagent, used as a source of electrons.
Besides zero-valent iron, discussed elsewhere, the most commonly used reagents
are dissolved sulfur compounds in different oxidation states: sulfides S(–II) are
represented by sodium hydrosulfide (NaHS), polysulfides S x (–II) by calcium
J. Němeček · S. Wacławek
Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of
Liberec, Liberec, Czech Republic
M. Černík (*)
Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of
Liberec, Liberec, Czech Republic
AQUATEST a.s., Prague, Czech Republic
e-mail: miroslav.cernik@tul.cz
© 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_3
53