scholarly journals Metallic iron for environmental remediation: the long walk to evidence

2013 ◽  
Vol 31 (2) ◽  
pp. 51-59 ◽  
Author(s):  
Chicgoua Noubactep
Keyword(s):  
Present Article ◽  
Metallic Iron ◽  
Environmental Remediation ◽  
Research Community ◽  
Mainstream Science

AbstractThe science of metallic iron for environmental remediation is yet to be established. The prevailing theory of the Fe0/H2O system is characterized by its inability to fully rationalize the concept that holds up the technology. The present article demonstrates that Fe0 technology was introduced by altering the course of mainstream science and by distorting the work of corrosion scientists. The Fe0 research community is now facing the consequences of this initial “forcing”. The technology is still innovative despite two decades of commercialization.

scholarly journals Characterizing the Reactivity of Metallic Iron for Water Treatment: H2 Evolution in H2SO4 and Uranium Removal Efficiency

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1523 ◽  
Author(s):  
Arnaud Igor Ndé-Tchoupé ◽  
Rui Hu ◽  
Willis Gwenzi ◽  
Achille Nassi ◽  
Chicgoua Noubactep
Keyword(s):  
Metallic Iron ◽  
Environmental Remediation ◽  
Material Selection ◽  
H2 Production ◽  
H2 Evolution ◽  
Solution Ph ◽  
Neutral Ph ◽  
Uranium Removal ◽  
Initial Reactivity

Metallic iron (Fe0) has been demonstrated as an excellent material for decentralized safe drinking water provision, wastewater treatment and environmental remediation. An open issue for all these applications is the rational material selection or quality assurance. Several methods for assessing Fe0 quality have been presented, but all of them are limited to characterizing its initial reactivity. The present study investigates H2 evolution in an acidic solution (pH 2.0) as an alternative method, while comparing achieved results to those of uranium removal in quiescent batch experiments at neutral pH values. The unique feature of the H2 evolution experiment is that quantitative H2 production ceased when the pH reached a value of 3.1. A total of twelve Fe0 specimens were tested. The volume of molecular H2 produced by 2.0 g of each Fe0 specimen in 560 mL H2SO4 (0.01 M) was monitored for 24 h. Additionally, the extent of U(VI) (0.084 mM) removal from an aqueous solution (20.0 mL) by 0.1 g of Fe0 was characterized. All U removal experiments were performed at room temperature (22 ± 2 °C) for 14 days. Results demonstrated the difficulty of comparing Fe0 specimens from different sources and confirmed that the elemental composition of Fe0 is not a stand-alone determining factor for reactivity. The time-dependent changes of H2 evolution in H2SO4 confirmed that tests in the neutral pH range just address the initial reactivity of Fe0 materials. In particular, materials initially reacting very fast would experience a decrease in reactivity in the long-term, and this aspect must be incorporated in designing novel materials and sustainable remediation systems. An idea is proposed that could enable the manufacturing of intrinsically long-term efficient Fe0 materials for targeted operations as a function of the geochemistry.

scholarly journals Metallic Iron for Environmental Remediation: Starting an Overdue Progress in Knowledge

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 641 ◽  
Author(s):  
Rui Hu ◽  
Huichen Yang ◽  
Ran Tao ◽  
Xuesong Cui ◽  
Minhui Xiao ◽  
...  
Keyword(s):  
Water Treatment ◽  
Literature Review ◽  
Metallic Iron ◽  
Environmental Remediation ◽  
Isotherm Models ◽  
Critical Survey ◽  
Root Cause ◽  
Water Provision ◽  
Adsorption Kinetics And Isotherm

A critical survey of the abundant literature on environmental remediation and water treatment using metallic iron (Fe0) as reactive agent raises two major concerns: (i) the peculiar properties of the used materials are not properly considered and characterized, and, (ii) the literature review in individual publications is very selective, thereby excluding some fundamental principles. Fe0 specimens for water treatment are typically small in size. Before the advent of this technology and its application for environmental remediation, such small Fe0 particles have never been allowed to freely corrode for the long-term spanning several years. As concerning the selective literature review, the root cause is that Fe0 was considered as a (strong) reducing agent under environmental conditions. Subsequent interpretation of research results was mainly directed at supporting this mistaken view. The net result is that, within three decades, the Fe0 research community has developed itself to a sort of modern knowledge system. This communication is a further attempt to bring Fe0 research back to the highway of mainstream corrosion science, where the fundamentals of Fe0 technology are rooted. The inherent errors of selected approaches, currently considered as countermeasures to address the inherent limitations of the Fe0 technology are demonstrated. The misuse of the terms “reactivity”, and “efficiency”, and adsorption kinetics and isotherm models for Fe0 systems is also elucidated. The immense importance of Fe0/H2O systems in solving the long-lasting issue of universal safe drinking water provision and wastewater treatment calls for a science-based system design.

scholarly journals Nanoscale Metallic Iron for Environmental Remediation: Prospects and Limitations

2011 ◽  
Vol 223 (3) ◽  
pp. 1363-1382 ◽  
Author(s):  
Chicgoua Noubactep ◽  
Sabine Caré ◽  
Richard Crane
Keyword(s):  
Metallic Iron ◽  
Environmental Remediation

scholarly journals Αναγνώριση σημαίνει ενοχή; Mια ανασκόπηση των παραγόντων επιρροής της επίδοσης των αυτοπτών μαρτύρων

2020 ◽  
Vol 19 (1) ◽  
pp. 63
Author(s):  
Άννα Σαγανά ◽  
Melanie Sauerland
Keyword(s):  
Present Article ◽  
Eyewitness Identification ◽  
Research Community ◽  
Judicial System ◽  
Identification Accuracy ◽  
Identification Performance ◽  
Wrongful Convictions ◽  
The Core ◽  
System Variables

Eyewitness identification stands as one of the core aspects of the judicial system. However, when it comes to identifying faces, people often make mistakes. Thus, it should not come as a surprise that eyewitness identification has been shown to be the number one factor of wrongful convictions (www.innoccenceproject.org). Therefore it is importantto understand the reasons that make eyewitnesses so error prone and investigate how we could enhance their performance. In the present article we examine the factors that have an impact on eyewitnessidentification performance. More specifically, we will refer to those variables over which the research community has reached consensus. These include estimator and system variables as well as postdictors,which are variables capable to diagnose the identification accuracy once it has taken place. In doing so we aim to reveal those parameters that are based on a sturdy research base, but have notwithstanding beenneglected by the Greek judicial system. We suggest a number of alterations and improvements, based on this research basis that can improve identification performance.

Fake Glosses? BStK-no. 837 revisited Gefälschte Glossen?: Zu BStK-Nr. 837

2020 ◽  
Vol 149 (1) ◽  
pp. 1-21
Author(s):  
Rolf Bergmann ◽  
Christina Beer ◽  
Michaela Pölzl ◽  
Stefanie Stricker
Keyword(s):  
Present Article ◽  
Research Community ◽  
Old High German ◽  
German Research

In 1894 the private scholar F.W.E. Roth published 14 Old High German glosses, which he claimed he had discovered in a manuscript in his own possession. Although the whereabouts of the manuscript have been unknown ever since, the glosses have been accepted as genuine by the Old High German research community. Recently the archivist Klaus Graf raised the suspicion that Roth had forged the 14 glosses mentioned above. The present article picks up Graf's request to review Roth's publication by taking his specifications regarding the manuscript into account and by investigating possible sources for the forgery. Der Privatgelehrte F. W. E. Roth veröffentlichte 1894 aus einer als in seinem Besitz befindlich bezeichneten, aber bis heute nicht auffindbaren Handschrift 14 althochdeutsche Glossen. Der Archivar Klaus Graf hat diese Glossenpublikation unter Fälschungsverdacht gestellt. Der damit verbundene Prüfungsauftrag an die Glossenforschung wird mit diesem Beitrag eingelöst.

scholarly journals Redirecting Research on Fe0 for Environmental Remediation: The Search for Synergy

2019 ◽  
Vol 16 (22) ◽  
pp. 4465 ◽  
Author(s):  
Hu ◽  
Noubactep
Keyword(s):  
Water Treatment ◽  
Metallic Iron ◽  
Environmental Remediation ◽  
Cathodic Reaction ◽  
Contaminant Removal ◽  
Iron Corrosion ◽  
Basic Relationship ◽  
Kinetics Of ◽  
Center Research

A survey of the literature on using metallic iron (Fe0) for environmental remediation suggests that the time is ripe to center research on the basic relationship between iron corrosion and contaminant removal. This communication identifies the main problem, which is based on the consideration that contaminant reductive transformation is the cathodic reaction of iron oxidative dissolution. Properly considering the inherent complexities of the Fe0/H2O system will favor an appropriate research design that will enable more efficient and sustainable remediation systems. Successful applications of Fe0/H2O systems require the collective consideration of progress achieved in understanding these system. More efforts should be made to decipher the long-term kinetics of iron corrosion, so as to provide better approaches to accurately predict the performance of the next generation Fe0-based water treatment systems.

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