Metallic Iron for Water Treatment: Lost Science in the West
Chicgoua Noubactep1,2
1Angewandte Geologie, Universität Göttingen, Goldschmidtstraße 3, D-37077, Göttingen, Germany.
2Pan African University Institute of Water and Energy Sciences (including Climate Change) PAUWES c/o University Abou Bekr Belkaïd - Tlemcen, B.P. 119, Pôle
Chetouane, Tlemcen 13000, Algeria.
*Corresponding author: Noubactep C, Angewandte Geologie, Universität Göttingen, Goldschmidtstraße 3, D-37077, Göttingen, Germany, Tel: 49 551 39 3 3191; Fax:
49 551 399379; E-mail: cnoubac@gwdg.de
Recevied date: Feb 23, 2017, Accepted date: Mar 15, 2017, Published date: Mar 21, 2017
Copyright: © 2017 Noubactep C. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and source are credited.
Letter to the Editor
Voltaire (1694-1778), the French philosopher said: “There are many
ways to waste own time: Doing nothing, doing the wrong thing, doing
the good thing at the wrong time” (own translation). The situation is
quite different if the time is robbed by someone else or even by a
professional mistake. There is a clear evidence that researchers on
metallic iron (Fe0 - termed as zero-valent iron) for water treatment as
performed for the past three decades have wasted time in wrongly
rediscovering aspects carefully documented in the scientific literature
[1,2] and textbooks [3,4] before 1940.
Actually, going through the Author's Guidelines of many scientific
journals, one realizes that referencing recent articles is strongly
recommended. This recommendation can be justified by the evidence,
that scientific knowledge is progressively accumulated, assuming that
all relevant available results are considered by newer publications.
Indeed, the state-of-the-art knowledge should be presented before
knowledge gaps are identified.
The recent introduction of the Fe0 technology for environmental
remediation was coupled with the assumption that contaminant
reductive degradation is the cathodic reaction simultaneous to Fe0
oxidative dissolution [5,6]. Efforts to support this statement reported
on works dating back to 1972 [7]. However, relevant works addressed
either (i) wastewater treatment or (ii) situations where Fe0 is used at
acidic pH values or in organic solvents [8,9]. The whole effort has
overseen the evidence that aqueous iron corrosion after Equation 1 is
spontaneous and quantitative. Thus, before discussing the impact of
any solute (usually present in trace amounts), the action of the solvent
(H2O or H+) should have been properly considered.
Fe0 + 2 H+→ Fe2+ + H2 (1)
Equation 1 shows clearly that Fe0 oxidative dissolution produces FeII
species and H2. Both are stand-alone reducing agents and their
reducing capacity is increased upon adsorption to mineral surfaces,
abundantly generated within the Fe0/H2O system [8,10,11]. Owning to
the low solubility of FeII (and FeIII) species at the pH values of natural
waters (pH>5.0), iron hydroxides and oxides are generated and act as
contaminant scavengers. This is the fundamental mechanism of
contaminant removal in Fe0/H2O system [8-13].
The contemporary Fe0 remediation technology was introduced for
groundwater remediation [7] and later scaled down for water
treatment at small scale [9,14]. This is exactly the opposite of what is
reported in the ancient use of Fe0 for safe drinking water provision
[1,2].
Around 1875, Fe0 was already established as material for water
filtration at household level [1,15]. Between 1881 and 1883 Fe0 filters
were successfully tested for water supply at large scale in Antwerp
(Belgium) [16,17]. The city then had 200,000 inhabitants. The best Fe0
filter used a porous material termed as sponge iron (Bischoff process).
Because filter clogging was difficult to control, the waterworks at
Antwerp developed and implemented the revolving purifier (Anderson
process) in which iron fillings are shaken with water to produce iron
hydroxides and oxides for contaminant removal [1,17,15]. This effort
preceded the introduction of iron electrocoagulation in water
treatment (1905) [18]. In other words, the ancient literature is rich in
scientific articles describing the mechanism of aqueous contaminant
removal by Fe0. That is considering Fe0 as generator of iron hydroxides
and oxides [9-11,12,15]. Properly considering this in 1990 would have
saved time for the whole research community.
Considering that a mechanistic discussion is still taking place within
the research community on Fe0 for water treatment and that this
research (was initiated and) is mainly performed in the Western
Europe and North America[19-21], it is fair to state that science loss
(knowledge loss) has occurred in the West. This is contrary to the
common belief that knowledge loss is characteristic of endangered
minorities in the Third World [22]. [22] gives an overview of
indigenous knowledge systems (IKSs). IKSs are bodies of knowledge of
the indigenous people of particular geographical areas. This locally
available knowledge can be opposed to mainstream science that is
universal in essence. [23] compared the current Fe0 research
community to a knowledge system challenging mainstream science. A
critical aspect of the behaviour of the Fe0 research community is that
issues of discussion are experimentally verifiable. Two examples for
illustration: (i) it has been redemonstrated that porous Fe0 materials
are the best choice for water filters [24] and (ii) the rationale for the
volumetric Fe0: gravel ratio of 1:3 used in the Bischoff process has been
established [25].
It is time for the Fe0 research community to go back to the highway
of mainstream science and accelerate a science-based development of
their technology. This simple and applicable technology has the
potential to help achieving the UN Sustainable Development. [26]
argued that a tool to achieve the UN SDGs is to translate existing
knowledge into practical solutions. It appears that designing efficient
Fe0 filtration systems is one of the best available approaches for an
appropriate, demand-based, affordable and efficient water treatment
technology [14].
Acknowledgement
The manuscript was improved by the insightful comments of
anonymous reviewers from Bioenergetics. The author acknowledges
support by the German Research Foundation and the Open Access
Publication Funds of the Gottingen University.
Bioenergetics: Open Access Noubactep, Bioenergetics 2017, 6:1DOI: 10.4172/2167-7662.1000149
Letter to Editor OMICS International
Bioenergetics, an open access journal
ISSN:2167-7662
Volume 6 • Issue 1 • 1000149
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Citation: Noubactep C (2017) Metallic Iron for Water Treatment: Lost Science in the West. Bioenergetics 6: 149. doi:10.4172/2167-7662.1000149
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ISSN:2167-7662
Volume 6 • Issue 1 • 1000149