Removal of heavy metals from water and brine using silicon alloys

McKaveney, J. P.; Fassinger, William P.; Stivers, D. A.

doi:10.1021/es60072a008

Cited by 14 publications

(12 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Silicon alloys (mainly of calcium, magnesium, and iron) were used by McKaveney et al [20], both in batch and column-filtration experiments, for the removal of several heavy metals from water and brine, including Cd II , Cr VI , Cu II , Fe II , Fe III , Hg II , Pb II and Zn II . It was shown by the column experiments that chromium removal only occurred when the alloy had sufficient time to reduce Cr VI to Cr III .…”

Section: Mckaveney Et Al (1972)mentioning

confidence: 99%

“…However, such acidic conditions are in contradiction with the working pH recommended to prolong the life of silicon alloys, which should be greater than 4.0. The authors suggested that Si alloys are acting as metallic exchangers and the mechanism responsible for the removal of heavy metals appears to be primarily electrochemical [20], analogous to cementation for divalent ions such as Cu II and Hg II [16]. For elements at higher oxidation states (>2), additional electrochemical mechanisms coupled with hydroxide formation through hydrolysis reactions were also suggested as possible.…”

Section: Mckaveney Et Al (1972)mentioning

confidence: 99%

“…For elements at higher oxidation states (>2), additional electrochemical mechanisms coupled with hydroxide formation through hydrolysis reactions were also suggested as possible. For instance, it was proposed that a Cr VI removal mechanism should comprise two steps: (1) Cr VI reduction to Cr III ; and (2) precipitation of Fe III and Cr III hydroxides [20].…”

Section: Mckaveney Et Al (1972)mentioning

confidence: 99%

See 2 more Smart Citations

Progress in Understanding the Mechanism of CrVI Removal in Fe0-Based Filtration Systems

Gheju¹

2018

Water

View full text Add to dashboard Cite

Hexavalent chromium (Cr VI ) compounds are used in a variety of industrial applications and, as a result, large quantities of Cr VI have been released into the environment due to inadequate precautionary measures or accidental releases. Cr VI is highly toxic to most living organisms and a known human carcinogen by inhalation route of exposure. Another major issue of concern about Cr VI compounds is their high mobility, which easily leads to contamination of surface waters, soil, and ground waters. In recent years, attention has been focused on the use of metallic iron (Fe 0 ) for the abatement of Cr VI polluted waters. Despite a great deal of research, the mechanisms behind the efficient aqueous Cr VI removal in the presence of Fe 0 (Fe 0 /H 2 O systems) remain deeply controversial. The introduction of the Fe 0 -based filtration technology, at the beginning of 1990s, was coupled with the broad consensus that direct reduction of Cr VI by Fe 0 was followed by co-precipitation of resulted cations (Cr III , Fe III ). This view is still the dominant removal mechanism (reductive-precipitation mechanism) within the Fe 0 remediation industry. An overview on the literature on the Cr geochemistry suggests that the reductive-precipitation theory should never have been adopted. Moreover, recent investigations recalling that a Fe 0 /H 2 O system is an ion-selective one in which electrostatic interactions are of primordial importance is generally overlooked. The present work critically reviews existing knowledge on the Fe 0 /Cr VI /H 2 O and Cr VI /H 2 O systems, and clearly demonstrates that direct reduction with Fe 0 followed by precipitation is not acceptable, under environmental relevant conditions, as the sole/main mechanism of Cr VI removal in the presence of Fe 0 .

show abstract

Section: Mckaveney Et Al (1972)mentioning

confidence: 99%

Section: Mckaveney Et Al (1972)mentioning

confidence: 99%

Section: Mckaveney Et Al (1972)mentioning

confidence: 99%

See 1 more Smart Citation

Progress in Understanding the Mechanism of CrVI Removal in Fe0-Based Filtration Systems

Gheju¹

2018

Water

View full text Add to dashboard Cite

show abstract

“…McKaveney et al 401 studied the removal of heavy metals from top waters and brine solutions by silicon alloys. The silicon alloys of calcium and magnesium were found to be the best silicon alloys for adsorption of heavy metals.…”

Section: Mineral Soilsmentioning

confidence: 99%

“…McKaveney et al 401 investigated the adsorption of mercury, zinc, copper, and cadmium by both anionic and cationic exchange resins. They found that cationic exchange resins accepted cadmium, zinc, and copper.…”

Section: Mineral Soilsmentioning

confidence: 99%

Mercury: Environmental considerations, Part II

Krenkel

Goldwater

1974

C R C Critical Reviews in Environmental Control

View full text Add to dashboard Cite

Calcium and Calcium Alloys

Hibbins¹

2000

Kirk-Othmer Encyclopedia of Chemical Technology

View full text Add to dashboard Cite

Calcium, Ca, a member of Group 2 (IIA) of the Periodic Table between magnesium and strontium, is classified, together with barium and strontium, as an alkaline‐earth metal and is the lightest of the three. Calcium metal does not occur free in nature; however, in the form of numerous compounds, it is the fifth most abundant element, constituting 3.63% of the earth's crust. Calcium is mainly used as a reducing agent for many reactive, less common metals; to remove bismuth from lead; as a desulfurizer and deoxidizer for ferrous metals and alloys; and as an alloying agent for aluminum, silicon, and lead. Pure calcium is a bright, silvery‐white metal, although under normal atmospheric conditions freshly exposed surfaces of calcium quickly become covered with an oxide layer. The metal is extremely soft and ductile. Calcium's usefulness as a structural material is limited by low tensile strength and high chemical reactivity. Calcium has a valence electron configuration of 4 s 2 and characteristically forms divalent compounds. It is very reactive and reacts vigorously with water, liberating hydrogen and forming calcium hydroxide, Ca(OH) 2 . Calcium does not readily oxidize in dry air at room temperature but is quickly oxidized in moist air or in dry oxygen at about 300°C. Calcium reacts with fluorine at room temperature and with the other halogens at 400°C. Calcium is an excellent reducing agent and is widely used for this purpose. Although in Western countries the aluminothermic process has completely replaced the electrolytic method, electrolysis is believed to be the method used for calcium production in the People's Republic of China and the Commonwealth of Independent States (CIS). Because of its extreme chemical reactivity, calcium metal must be carefully packaged for shipment and storage. The metal is packaged in sealed argon‐filled containers. Calcium is classed as a flammable solid and is nonmailable. Calcium metal and most calcium compounds are nontoxic. Care must be taken, however, to avoid contact with water owing to the exothermic liberation of hydrogen and the resulting explosion hazard. Direct alloying of the pure metals is normally used in the production of 80% calcium–magnesium, 70% magnesium–calcium, and 75% calcium–aluminum alloys.

show abstract

Removal of heavy metals from water and brine using silicon alloys

Cited by 14 publications

References 2 publications

Progress in Understanding the Mechanism of CrVI Removal in Fe0-Based Filtration Systems

Progress in Understanding the Mechanism of CrVI Removal in Fe0-Based Filtration Systems

Mercury: Environmental considerations, Part II

Calcium and Calcium Alloys

Contact Info

Product

Resources

About