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Arsenic removal by liquid membranes.

Marino T, Figoli A - Membranes (Basel) (2015)

Bottom Line: The development of different LM configurations has been a matter of investigation by several researching groups, especially for the removal of As(III) and As(V) from aqueous solutions.Most of these LM systems are based on the use of phosphine oxides as carriers, when the metal removal is from sulfuric acid media.For such LM configuration, the most relevant step toward efficiency is the choice of the surfactant type and its concentration.

View Article: PubMed Central - PubMed

Affiliation: Institute on Membrane Technology, ITM-CNR, Via Pietro Bucci 17/c, 87030, Rende (CS), Italy. t.marino@itm.cnr.it.

ABSTRACT
Water contamination with harmful arsenic compounds represents one of the most serious calamities of the last two centuries. Natural occurrence of the toxic metal has been revealed recently for 21 countries worldwide; the risk of arsenic intoxication is particularly high in Bangladesh and India but recently also Europe is facing similar problem. Liquid membranes (LMs) look like a promising alternative to the existing removal processes, showing numerous advantages in terms of energy consumption, efficiency, selectivity, and operational costs. The development of different LM configurations has been a matter of investigation by several researching groups, especially for the removal of As(III) and As(V) from aqueous solutions. Most of these LM systems are based on the use of phosphine oxides as carriers, when the metal removal is from sulfuric acid media. Particularly promising for water treatment is the hollow fiber supported liquid membrane (HFSLM) configuration, which offers high selectivity, easy transport of the targeted metal ions, large surface area, and non-stop flow process. The choice of organic extractant(s) plays an essential role in the efficiency of the arsenic removal. Emulsion liquid membrane (ELM) systems have not been extensively investigated so far, although encouraging results have started to appear in the literature. For such LM configuration, the most relevant step toward efficiency is the choice of the surfactant type and its concentration.

No MeSH data available.


Related in: MedlinePlus

Global arsenic occurrence in groundwater.
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membranes-05-00150-f001: Global arsenic occurrence in groundwater.

Mentions: Arsenic (As) is a toxic metal that derives its name from the Greek word “arsenikon” meaning “yellow orpiment” [1]. The metalloid element occurs in the nature in various oxidation states, such as As(V), As(III), As(0) and As (-III). Environmental species include arsenious acids (H3AsO3, H3AsO3, H3AsO32−), arsenic acids (H3AsO4, H3AsO4–, H3AsO42−), arsenites (AsO33−, As(OH)3, As(OH)4−, AsO2OH2−), arsenates (AsO43−, HAsO42−, H2AsO4−), methylarsenic acid (CH5AsO3), dimethylarsinic acid (C2H7AsO2), arsine (AsH3), etc. The hazardous effect is strongly related to its oxidation state [2]. The two predominant species—arsenite and arsenate, in which the oxidation states are As(III) and As(V)—have become problematic in many areas in the world because of their high toxicity for humans and the environment [3,4]. In particular, arsenite, although it is present at low concentrations in water, is more toxic than the other species. Serious pollution has been registered recently in the USA, Canada, Mexico, Chile, Argentina, Hungary, Poland, China, Bangladesh, New Zeland, Japan, India, and Italy [5,6,7,8,9,10] (Figure 1). Bangladesh and India are the two countries with the highest contamination risk.


Arsenic removal by liquid membranes.

Marino T, Figoli A - Membranes (Basel) (2015)

Global arsenic occurrence in groundwater.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4496637&req=5

membranes-05-00150-f001: Global arsenic occurrence in groundwater.
Mentions: Arsenic (As) is a toxic metal that derives its name from the Greek word “arsenikon” meaning “yellow orpiment” [1]. The metalloid element occurs in the nature in various oxidation states, such as As(V), As(III), As(0) and As (-III). Environmental species include arsenious acids (H3AsO3, H3AsO3, H3AsO32−), arsenic acids (H3AsO4, H3AsO4–, H3AsO42−), arsenites (AsO33−, As(OH)3, As(OH)4−, AsO2OH2−), arsenates (AsO43−, HAsO42−, H2AsO4−), methylarsenic acid (CH5AsO3), dimethylarsinic acid (C2H7AsO2), arsine (AsH3), etc. The hazardous effect is strongly related to its oxidation state [2]. The two predominant species—arsenite and arsenate, in which the oxidation states are As(III) and As(V)—have become problematic in many areas in the world because of their high toxicity for humans and the environment [3,4]. In particular, arsenite, although it is present at low concentrations in water, is more toxic than the other species. Serious pollution has been registered recently in the USA, Canada, Mexico, Chile, Argentina, Hungary, Poland, China, Bangladesh, New Zeland, Japan, India, and Italy [5,6,7,8,9,10] (Figure 1). Bangladesh and India are the two countries with the highest contamination risk.

Bottom Line: The development of different LM configurations has been a matter of investigation by several researching groups, especially for the removal of As(III) and As(V) from aqueous solutions.Most of these LM systems are based on the use of phosphine oxides as carriers, when the metal removal is from sulfuric acid media.For such LM configuration, the most relevant step toward efficiency is the choice of the surfactant type and its concentration.

View Article: PubMed Central - PubMed

Affiliation: Institute on Membrane Technology, ITM-CNR, Via Pietro Bucci 17/c, 87030, Rende (CS), Italy. t.marino@itm.cnr.it.

ABSTRACT
Water contamination with harmful arsenic compounds represents one of the most serious calamities of the last two centuries. Natural occurrence of the toxic metal has been revealed recently for 21 countries worldwide; the risk of arsenic intoxication is particularly high in Bangladesh and India but recently also Europe is facing similar problem. Liquid membranes (LMs) look like a promising alternative to the existing removal processes, showing numerous advantages in terms of energy consumption, efficiency, selectivity, and operational costs. The development of different LM configurations has been a matter of investigation by several researching groups, especially for the removal of As(III) and As(V) from aqueous solutions. Most of these LM systems are based on the use of phosphine oxides as carriers, when the metal removal is from sulfuric acid media. Particularly promising for water treatment is the hollow fiber supported liquid membrane (HFSLM) configuration, which offers high selectivity, easy transport of the targeted metal ions, large surface area, and non-stop flow process. The choice of organic extractant(s) plays an essential role in the efficiency of the arsenic removal. Emulsion liquid membrane (ELM) systems have not been extensively investigated so far, although encouraging results have started to appear in the literature. For such LM configuration, the most relevant step toward efficiency is the choice of the surfactant type and its concentration.

No MeSH data available.


Related in: MedlinePlus