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Arsenic removal by liquid membranes.

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

Bottom Line: 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.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.

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.


Ppm of arsenic ions from outlet feed solution against the number of cycle operations through HFSLM using Aliquat 336 35% (v/v) and 0.5M NaOH. Feed flow rate: 100 mL/min; Stripping solution flow rate: 100 mL/min [49].
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membranes-05-00150-f005: Ppm of arsenic ions from outlet feed solution against the number of cycle operations through HFSLM using Aliquat 336 35% (v/v) and 0.5M NaOH. Feed flow rate: 100 mL/min; Stripping solution flow rate: 100 mL/min [49].

Mentions: High percentages of arsenic ion recovery were observed when Aliquat 336 was employed, due to the extractant’s ability to react with the dissociated (H2AsO4− and HAsO4) and undissociated (H3AsO3) metal species. The best results were obtained using the HFSLM containing 0.5 M stripping solution and 0.75 M carrier. Working under these operational conditions, after several separation runs through the HFSLM, it was possible to successfully reduce As ion content in the produced water from the gas separation plant in the Gulf of Thailand at levels lower than 250 parts per billion (ppb), which represents the permissible limit established by the Ministry of Industry in Thailand [50] (Figure 5).


Arsenic removal by liquid membranes.

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

Ppm of arsenic ions from outlet feed solution against the number of cycle operations through HFSLM using Aliquat 336 35% (v/v) and 0.5M NaOH. Feed flow rate: 100 mL/min; Stripping solution flow rate: 100 mL/min [49].
© Copyright Policy
Related In: Results  -  Collection

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

membranes-05-00150-f005: Ppm of arsenic ions from outlet feed solution against the number of cycle operations through HFSLM using Aliquat 336 35% (v/v) and 0.5M NaOH. Feed flow rate: 100 mL/min; Stripping solution flow rate: 100 mL/min [49].
Mentions: High percentages of arsenic ion recovery were observed when Aliquat 336 was employed, due to the extractant’s ability to react with the dissociated (H2AsO4− and HAsO4) and undissociated (H3AsO3) metal species. The best results were obtained using the HFSLM containing 0.5 M stripping solution and 0.75 M carrier. Working under these operational conditions, after several separation runs through the HFSLM, it was possible to successfully reduce As ion content in the produced water from the gas separation plant in the Gulf of Thailand at levels lower than 250 parts per billion (ppb), which represents the permissible limit established by the Ministry of Industry in Thailand [50] (Figure 5).

Bottom Line: 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.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.

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.