KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 8 of 8

Some of the metrics are blocked by your
consent settings
Uphill transport and mathematical model of Pb(II) from dilute synthetic lead-containing solutions across hollow fiber supported liquid membrane
(2012-05-15)
Suren, Sira
;
Wongsawa, Thidarat
;
Pancharoen, Ura
;
Prapasawat, Tatchanok
;
Lothongkum, Anchaleeporn Waritswat
This work presents an experimental investigation and mathematical model of Pb(II) separation and stripping from relatively low-level lead-containing synthetic solutions through a hollow fiber supported liquid membrane (HFSLM) by using di-2-ethylhexyl phosphoric acid (D2EHPA) in toluene as an extractant or carrier. The separation was studied on several variables: concentration of D2EHPA, types of stripping solutions (distilled water, HNO <inf>3</inf>, H <inf>2</inf>SO <inf>4</inf> and HCl), concentration of the selected stripping solution, flow patterns of feed and stripping solutions, types of lead-containing solutions (Pb(NO <inf>3</inf>) <inf>2</inf> and PbCl <inf>2</inf>), and flow rates of feed and stripping solutions. The results remarkably showed that HFSLM could successfully reduce a very low concentration of Pb(II) in feed solution to less than the regulatory discharge limit of 0.2mg/L issued by the Ministry of Industry and the Ministry of Natural Resource Environment, Thailand. The highest extraction and stripping results were achieved by using 0.03M D2EHPA, 0.9M HCl at equal flow rates of feed and stripping solutions of 100mL/min using a single-pass of feed solution and circulating of stripping solution. High percentages of extraction and stripping were observed from both Pb(NO <inf>3</inf>) <inf>2</inf> and PbCl <inf>2</inf> solutions. The kinetics of Pb(NO <inf>3</inf>) <inf>2</inf> and PbCl <inf>2</inf> separation were corresponded to second-order reaction with the rate constants of 1.49 and 1.51L/mgmin, respectively. The prediction of Pb(II) concentrations in the outlet Pb(NO <inf>3</inf>) <inf>2</inf> and PbCl <inf>2</inf> feed solutions obtaining from mathematical model were in good agreement with the experimental results at the average percent deviations of 4% for Pb(NO <inf>3</inf>) <inf>2</inf> solution and 8% for PbCl <inf>2</inf> solution. © 2012 Elsevier B.V.
Some of the metrics are blocked by your
consent settings
A reaction flux model for extraction of Cu(ii) with LIX84i in HFSLM
(2011-09-01)
Pancharoen, Ura
;
Wongsawa, Thidarut
;
Lothongkum, Anchaleeporn W.
Hollow fiber supported liquid membrane (HFSLM) is a favorable method to extract both valuable compounds and heavy metal pollutants such as chromium, copper, and nickel at a very low concentration. In this work, the extraction of Cu(II) by LIX84I dissolved in kerosene was theoretically and experimentally investigated. A model to estimate the percentage of extraction of copper ions from synthetic water considering the effect of reaction flux in membrane phase of the HFSLM system was studied. H<inf>2</inf>SO<inf>4</inf> solution was used as the stripping solution. The facilitated transport mechanism of the chemical reaction at the feed-membrane interface was taken into account in the model equations. The percentage of copper ion extraction was plotted against its initial concentration in feed and also feed flow rate. Subsequently, the separation time and separation cycle were determined in accordance with the simulated values of copper ion concentration and the feed flow rate from the model. The modeled results were in good agreement with the experimental data at the average percentage of deviation about 2%. © Taylor & Francis Group, LLC.
Some of the metrics are blocked by your
consent settings
Enhancement of uranium ion flux by consecutive extraction via hollow fiber supported liquid membrane
(2009-09-01)
Lothongkum, A. W.
;
Ramakul, P.
;
Sasomsub, W.
;
Laoharochanapan, S.
;
Pancharoen, U.
The enhancement of uranium separation from trisodium phosphate, a by-product, from monazite processing through a supported liquid membrane system by a consecutive extraction using the synergistic extractants is first time demonstrated in this work. Feed solution was trisodium phosphate solution containing uranium ions of 45 ppm, and the stripping solution was nitric acid solution. The effects of types and concentrations of the extractants, concentration of HNO<inf>3</inf>, flow rates of feed and stripping solutions and the numbers of cycles on extraction efficiency were investigated. D2EHPA, Cyanex 923, TBP, TOA and Aliquat 336 dissolved in kerosene were used as the extractants. The results showed that by using the synergistic extractant of Aliquat 336 mixed with TBP, the percentages of extraction and stripping or recovery considerably increased higher than those obtained by a single extractant. For the seventh-cycle separation by one-module operation using 0.1 M Aliquat 336 and 0.06 M TBP mixture, 0.5 M HNO<inf>3</inf>, and equal flow rates of feed and stripping solutions at 100 mL/min, the percentages of extraction and stripping reached 99 and 53 in 350 min. The amount of uranium ions remaining in trisodium phosphate solution was 0.22 ppm, which stayed within the standard value of technical grade trisodium phosphate of 3 ppm. © 2009 Taiwan Institute of Chemical Engineers.
Some of the metrics are blocked by your
consent settings
Treatment of arsenic ions from produced water through hollow fiber supported liquid membrane
(2009-08-12)
Pancharoen, Ura
;
Poonkum, Woradej
;
Lothongkum, Anchaleeporn Waritswat
Treatment of arsenic ions from produced water coming along with a gas separation plant in the Gulf of Thailand by hollow fiber supported liquid membrane (HFSLM) was studied. Cyanex® 923 (a mixture of phosphine oxide), tri-n-butylphosphate (TBP), bis(2, 4, 4-trimethylpentyl) dithiophosphinic acid (Cyanex® 301), tri-n-octylamine (TOA) and methyltrioctylammonium chloride (Aliquat 336) were used as the extractants. The stripping solution was sodium hydroxide. The concentration of the extractant in liquid membrane and concentration of sodium hydroxide were examined. In addition, the influence of various numbers of runs of the stripping solution through the HFSLM on the concentration of arsenic ions in the outlet stripping solution was observed. Of all the extractants used, 35% (v/v) Aliquat 336 attained high percentages of extraction and recovery of arsenic ions because it reacted with both undissociated arsenic (H<inf>3</inf>AsO<inf>3</inf>) and dissociated arsenics (H<inf>2</inf>AsO<inf>4</inf>- and HAsO<inf>4</inf>2-). Cyanex® 923, TBP and TOA had low extractability since Cyanex® 923 and TBP reacted only with undissociated forms while TOA reacted only with dissociated forms. In case of Cyanex® 301, although it offered a relatively high percentage of extraction but very poor recovery due to this extractant formed very strong complex species with arsenic ions, which slowed down and made the stripping difficult. It was found that the percentage of arsenic recovery increased with the concentration of sodium hydroxide and was almost constant after 0.5 M due to the limitation of mass transfer area of the hollow fibers. After 3-cycle separation, the extraction and recovery of arsenic ions from produced water were 91% and 72%, respectively. Accordingly, the concentration of arsenic ions of 0.1201 ppm in produced water was observed, which was in accordance with the legislation discharge of industrial effluent in Thailand. More arsenic ions were recovered by increasing the numbers of runs of the recycling stripping solution through the HFSLM. © 2009 Elsevier B.V. All rights reserved.
Some of the metrics are blocked by your
consent settings
Selective recovery of nickel ions from wastewater of stainless steel industry via HFSLM
(2009-05-12)
Lothongkum, Anchaleeporn Waritswat
;
Khemglad, Yuttapong
;
Usomboon, Nantawat
;
Pancharoen, Ura
High concentration of heavy metal ions in all kinds of effluents, especially in wastewater is of great concern for hazardous pollution due to their high toxicities and wide environmental spreading. The selective stripping or recovery of nickel ions from wastewater of the stainless steel-cold rolled plate process by hollow fiber supported liquid membrane was studied. The optimum conditions were examined in a batch process. The pH of feed, types and concentrations of the extractants, concentration of the stripping solution (sulfuric acid), flow rates of feed and stripping solutions, and volumetric ratio of feed to stripping solutions were investigated. The extractants, i.e., D2EHPA, Cyanex 301, Cyanex 272 and LIX 860-I were dissolved in kerosene as a membrane solution, which was supported by a microporous hydrophobic hollow fiber membrane extractor. Consequently, two consecutive modules of hollow fiber were applied to recover more nickel ions. The results showed that LIX 860-I was the most effective to selectively retrieve nickel ions from wastewater at a feed pH of 4. The percentage of the recovery and selectivity of nickel ions increased in accordance with an increase in the concentration of LIX 860-I and decreased after the concentration of LIX 860-I was higher than 0.8 M. It was found that the percentage of recovery of nickel ions increased with sulfuric acid concentration and lower flow rates of feed and stripping solutions. Higher nickel ions were obtained at the flow rates of feed and stripping solutions of 100 ml/min and reduced when the flow rates increased. In addition, in this study it is recommended to use equal volume of feed and stripping solutions of 3500:3500 (ml:ml) to attain more nickel ions recovery. For a single-module operation, the percentage of recovery of nickel ions was 58%, and 87% by double-module operation. © 2008 Elsevier B.V. All rights reserved.
Some of the metrics are blocked by your
consent settings
Performance of hollow fiber supported liquid membrane on the extraction of mercury(II) ions
(2008-11-01)
Uedee, Ekapong
;
Ramakul, Prakorn
;
Pancharoen, Ura
;
Lothongkum, Anchaleeporn W.
The extraction and recovery or stripping of mercury ions from chloride media using microporous hydrophobic hollow fiber supported liquid membranes (HFSLM) has been studied. Tri-n-octylamine (TOA) dissolved in kerosene was used as an extractant. Sodium hydroxide was used as a stripping solution. The transport system was studied as a function of several variables: the concentration of hydrochloric acid in the feed solution, the concentration of TOA in the liquid membrane, the concentration of sodium hydroxide in the stripping solution, the concentration of mercury ions in the feed solution and the flow rates of both feed and stripping solutions. The results indicated that the maximum percentages of the extraction and recovery of mercury ions of 100% and 97% were achieved at the concentration of hydrochloric acid in the feed solution of 0.1 mol/l, the concentration of TOA at 3% v/v, the concentration of sodium hydroxide at 0.5 mol/l and the flow rates of the feed and stripping solutions of 100 ml/min. However, the concentration of mercury ions from 1-100 ppm in the feed solution had no effect on the percentages of extraction and recovery of mercury ions. Thus, these results have identified that the hollow fiber supported liquid membrane process has high efficiency on both the extraction and recovery of mercury (II) ions. Moreover, the mass transfer coefficients of the aqueous phase (k <inf>i</inf> ) and membrane or organic phase (k <inf>m</inf> ) were calculated. The mass transfer coefficients of the aqueous phase and organic phase are 0.42 and 1.67 cm/s, respectively. The mass transfer coefficient of the organic phase is higher than that of the aqueous phase. Therefore, the mass transfer controlling step is the diffusion of the mercury ions through the film layer between the feed solution and the liquid membrane. © 2008 Springer.
Some of the metrics are blocked by your
consent settings
Separation of As(III) and As(V) by hollow fiber supported liquid membrane based on the mass transfer theory
(2008-01-01)
Prapasawat, Tatchanok
;
Ramakul, Prakorn
;
Satayaprasert, Chairit
;
Pancharoen, Ura
;
Lothongkum, Anchaleeporn W.
Separation of As(III) and As(V) ions from sulphate media by hollow fiber supported liquid membrane has been examined. Cyanex 923 was diluted in toluene and used as an extractant. Water was used as a stripping solution. The extractability of As(V) was higher than As(III). When the concentration of sulphuric acid in feed solution and Cyanex 923 in liquid membrane increased, more arsenic ions were extracted into liquid membrane and recovered into the stripping solution. The mathematical model was focused on the extraction side of the liquid membrane system. The mass transfer coefficients of the aqueous phase (k <inf>i</inf> ) and organic phase (k <inf>m</inf> ) are 7.15×10 -3 and 3.45×10-2 cm/s for As(III), and 1.07×10-2 and 1.79×10-2 cm/s for As(V). Therefore, the rate-controlling step for As(III) and As(V) in liquid membrane process is the mass transfer in the aqueous film between the feed solution and liquid membrane. The calculated mass transfer coefficients agree with the experimental results. © 2008 Springer.
Some of the metrics are blocked by your
consent settings
Purely separation of mixture of mercury and arsenic via hollow fiber supported liquid membrane
(2007-09-01)
Sangtumrong, Seewalee
;
Ramakul, Prakom
;
Satayaprasert, Chairit
;
Pancharoen, Ura
;
Lothongkum, Anchaleeporn W.
The separation of mercury(II) and arsenic(III) ions from chloride media has been examined through a hollow fiber supported liquid membrane using tri-n-octylamine (TOA) as an extractant dissolved in toluene. The transport system was studied as a function of several variables: the concentration of the hydrochloric acid feed solutions, the concentration of TOA in the liquid membrane, the concentration of sodium hydroxide in the recovery solutions. According to the system, mercury(II) ions were extracted using TOA by rejecting arsenic (III) ions into raffinate because of the different forms of the mercury(II) and arsenic(III) ions in hydrochloric acid solutions. The maximum percentage of recovery for mercury(II) was 95 %; 100 % selectivity was obtained.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results