Received date: February 23, 2017; Accepted date: March 15, 2017; Published date: Mar 21, 2017
Citation: Noubactep C (2017) Metallic Iron for Water Treatment: Lost Science in the West. Bioenergetics 6:149. doi:10.4172/2167-7662.1000149
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.
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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 . 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  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) . 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 .  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.  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  and (ii) the rationale for the volumetric Fe0: gravel ratio of 1:3 used in the Bischoff process has been established .
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.  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 .
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.