Legiertes Gußeisen

Piwowarsky, Eugen

doi:10.1007/978-3-642-53133-0_19

Cited by 3 publications

(2 citation statements)

References 28 publications

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“…Cast iron and mild steel are unequaled in terms of mechanical and physical properties derived from alloying and heat-treatment. Almost all these materials corrode in a wide range of aqueous environments [20,23,33,38,[56][57][58]. Some general statements occur in the literature on the effects of alloying on the corrosion properties of cast iron and mild steel in water [57,59].…”

Section: Fe 0 Materialsmentioning

confidence: 99%

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

Ndé-Tchoupé

Gwenzi

et al. 2020

Water

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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.

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Section: Fe 0 Materialsmentioning

confidence: 99%

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

Ndé-Tchoupé

Gwenzi

et al. 2020

Water

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“…The main influencing operational parameter seems to be Fe 0 itself [58,61,63,64]. In fact, data from the open corrosion literature demonstrate that at pH > 4.5, the extent of iron corrosion depends on the relative kinetics of iron oxidative dissolution (corrosion) and of the precipitation of resulting iron hydroxides and oxides (oxide-scale formation) [65][66][67][68][69]. Accordingly, when iron hydroxide precipitates at the Fe 0 surface or in its vicinity, it slows down the further dissolution process by partly or entirely shielding the Fe 0 surface for the species involved in the corrosion process, including dissolved oxygen and reducible contaminants [70][71][72].…”

mentioning

confidence: 99%

The Impact of Selected Pretreatment Procedures on Iron Dissolution from Metallic Iron Specimens Used in Water Treatment

Ndé-Tchoupé

Lufingo

et al. 2019

Sustainability

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Studies were undertaken to determine the reasons why published information regarding the efficiency of metallic iron (Fe 0 ) for water treatment is conflicting and even confusing. The reactivity of eight Fe 0 materials was characterized by Fe dissolution in a dilute solution of ethylenediaminetetraacetate (Na 2 -EDTA; 2 mM). Both batch (4 days) and column (100 days) experiments were used. A total of 30 different systems were characterized for the extent of Fe release in EDTA. The effects of Fe 0 type (granular iron, iron nails and steel wool) and pretreatment procedure (socking in acetone, EDTA, H 2 O, HCl and NaCl for 17 h) were assessed. The results roughly show an increased iron dissolution with increasing reactive sites (decreasing particle size: wool > filings > nails), but there were large differences between materials from the same group. The main output of this work is that available results are hardly comparable as they were achieved under very different experimental conditions. A conceptual framework is presented for future research directed towards a more processed understanding.Sustainability 2019, 11, 671 2 of 20 organic [27,28], fluoride [29][30][31], heavy metals [32,33], nitrate [34,35], pathogens [36][37][38] and radionuclides [32,39]. The desalination of water using Fe 0 has also been reported [40][41][42][43]. The two key advantages of Fe 0 are its affordability and its universal availability (iron nails, scrap iron and steel wool) [9,10,44,45]. It is commonly reported that the major drawback of Fe 0 -based technologies for water treatment is the low intrinsic reactivity of granular materials [28,33,46]. This situation is said to be aggravated by the inherent generation of an oxide scale at the Fe 0 surface (passivation). Countermeasures to overcome Fe 0 passivation were recently reviewed by Guan et al. [28] and further discussed by Noubactep [47]. It is recalled that, considering passivation as a "curse" contradicts the evidence that Fe 0 -based subsurface permeable barriers have been successfully working for more than one decade [48][49][50]. On the other hand, increased "passivation" should have occurred in the spongy iron filters in Antwerpen as well [2,19]. Clarifying this contradiction is certainly a progress for the whole Fe 0 technology. Clearly, an understanding of the role of "passivation" in the process of decontamination using Fe 0 should be useful for enhancing the system's efficiency in practice [30,31,47].There is an agreement on the evidence that using Fe 0 for water treatment and environmental remediation is "putting corrosion to use" [51][52][53]. There is otherwise a contradiction on practically any other aspect concerning the Fe 0 /H 2 O system, including the reaction mechanisms and factors determining the long-term efficiency of such systems [9,28,47,[54][55][56][57][58]. A key reason for this is the large variability of experimental conditions used in testing Fe 0 materials [58][59][60][61][62]. The main influencing operational parameter seems to be Fe 0 itself [58,61,63,6...

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Patterson¹,

Standke²

1966

Einfluß Der Einsatzstoffe, Der Schmelzführung Im Induktionsofen Und Der Impfbehandlung Auf Das Gefüge Und Die Mechanischen Eige

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Legiertes Gußeisen

Cited by 3 publications

References 28 publications

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

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

The Impact of Selected Pretreatment Procedures on Iron Dissolution from Metallic Iron Specimens Used in Water Treatment

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