The aim of this study was to design a new emulsion liquid membrane(ELM)system for the separation of succinic acid from aqueous solutions.The concentration of succinic acid varied from 20 to 60 mmol·L^(-1).The pre...The aim of this study was to design a new emulsion liquid membrane(ELM)system for the separation of succinic acid from aqueous solutions.The concentration of succinic acid varied from 20 to 60 mmol·L^(-1).The prepared ELM system includes tributylamine(TBA)as a carrier,commercial kerosene as a solvent,Span 80 as a surfactant,and Na2CO3as a stripping agent.In order to control the membrane swelling,different values of cyclohexanone were added to the membrane phase.The effect of various empirical variables on the extraction of the succinic acid such as acid concentration in the feed solution,initial feed concentration,carrier concentration,the stirring speed of the extraction,Na2CO3,surfactant,and cyclohexanone concentrations,and treat ratio in the ELM system.The best result was obtained when TBA was used as the carrier.The final acid extraction efficiency was independent of pH variations of the aqueous feed solution.The extraction of succinic acid solution with a concentration of 40 mmol·L^(-1)was improved by increasing the treat ratio 1:7-1:3,stripping phase concentration 0.5-1.5 mol·L^(-1),stirring speed 300-500 r·min^(-1)and cyclohexanone concentration in the membrane phase 1.2-1.6 mol·L^(-1).No considerable effect on the extraction rate was observed for the carrier concentration in the membrane phase.But,the surfactant concentration in the feed phase showed a dual effect on the extraction efficiency.展开更多
Phenol is considered as pollutant due to its toxicity and carcinogenic effect.Thus,variety of innovative methods for separation and recovery of phenolic compounds is developed in order to remove the unwanted phenol fr...Phenol is considered as pollutant due to its toxicity and carcinogenic effect.Thus,variety of innovative methods for separation and recovery of phenolic compounds is developed in order to remove the unwanted phenol from wastewater and obtain valuable phenolic compound.One of potential method is extraction using green based liquid organic solvent.Therefore,the feasibility of using palm oil was investigated.In this research,palm oil based organic phase was used as diluents to treat a simulated wastewater containing 300×10^(-6) of phenol solution using emulsion liquid membrane process(ELM).The stability of water-in-oil(W/O) emulsion on diluent composition and the parameters affecting the phenol removal efficiency and stability of the emulsion;such as emulsification speed,emulsification time,agitation speed,surfactant concentration,pH of external phase,contact time,stripping agent concentration and treat ratio were carried out.The results of ELM study showed that at ratio7 to 3 of palm oil to kerosene,5 min and 1300 r·min^(-1) of emulsification process the stabile primary emulsion were formed.Also,no carrier is needed to facilitate the phenol extraction.In experimental conditions of500 r·min^(-1) of agitation speed,3%Span 80,pH 8 of external phase,5 min of contact time,0.1 mol·L^(-1) NaOH as stripping agent and 1:10 of treat ratio,the ELM process was very promising for removing the phenol from the wastewater.The extraction performance at about 83%of phenol was removed for simulated wastewater and an enrichment of phenol in recovery phase as phenolate compound was around 11 times.展开更多
Recovery of copper ions from wastewater using a hollow fiber supported emulsion liquid membrane (HFSELM) was studied with LIX984N as carrier, kerosene as diluents, and sulfuric acid solution as stripping phase. Effect...Recovery of copper ions from wastewater using a hollow fiber supported emulsion liquid membrane (HFSELM) was studied with LIX984N as carrier, kerosene as diluents, and sulfuric acid solution as stripping phase. Effects of compositions of feed and emulsion liquid phase, flow rates on both sides of membrane, and hollow fiber module parameters were investigated. The stability of the emulsion liquid phase without surfactant and the effect of buffer in the feed phase on the extraction rate were also evaluated. It is found that the stability of the emulsion phase without surfactant is poor. Higher flow velocity gives shorter residence time for the emulsion liquid phase on the tube side, reducing the effect of particle coalescence on the separation process. The extraction rate increases with the increase of feed phase pH, carrier concentration, hydrogen ion concentration in the stripping phase, and ef- fective hollow fiber area. The phase ratio in the emulsion liquid phase has a negative effect on extraction rate. The flow rates on both sides have little influence on the extraction performance of the HFSELM, while buffer addition in the feed solution improves the extraction efficiency.展开更多
Permeation of Cu(Ⅱ) from its aqueous solution through a supported liquid membrane (SLM) containing di(2-ethylhexyl)phosphoric acid (D2EHPA) carrier dissolved in coconut oil has been studied. The effects of C...Permeation of Cu(Ⅱ) from its aqueous solution through a supported liquid membrane (SLM) containing di(2-ethylhexyl)phosphoric acid (D2EHPA) carrier dissolved in coconut oil has been studied. The effects of Cu(Ⅱ), pH (in feed), H2SO4 (stripping) and D2EHPA (in membrane) concentrations have been investigated. The stability of the D2EHPA-coconut oil has also been evaluated. High Cu(Ⅱ) concentration in the feed leads to an increase in flux from 4.1 × 10^-9 to 8.9 × 10^-9 mol/(m^2·s) within the Cu(Ⅱ) concentration range 7.8×10^-4-78.6×10^-4 mol/L at pH of 4.0 in the feed and 12.4 × 10^-4 mol/L D2EHPA in the membrane phase. Increase in H2SO4 concentration in strip solution leads to an increase in copper ions flux up to 0.25 mol/L H2SO4, providing a maximum flux of 7.4 × 10^-9 mol/(m^2·s). The optimum conditions for Cu(Ⅱ) transport are, pH of feed 4.0, 0.25 mol/L H2SO4 in strip phase and 12.4 × 10^-4 mol/L D2EHPA (membrane) in 0.5 μm pore size polytetrafluoroethylene (PTFE) membrane. It has been observed that Cu(Ⅱ) flux across the membrane tends to increase with the concentration of copper ions. Application of the method developed to copper plating bath rinse solutions has been found to be successful in the recovery of Cu(Ⅱ).展开更多
It is indicated from a study of transport of rare earth ions through the emulsion liquid mem- brane of bis(2,4,4-trimethylpentyl)phosphinic acid-Span 80-toluene that transporting rare earth ions com- pletely and rapid...It is indicated from a study of transport of rare earth ions through the emulsion liquid mem- brane of bis(2,4,4-trimethylpentyl)phosphinic acid-Span 80-toluene that transporting rare earth ions com- pletely and rapidly was realized under the optimum experimental conditions:1.0×10^(-3)~3.0×10^(-3)mol/L bis(2,4,4-trimethylpentyl)phosphinic acid and 2%~4%(W/V)Span 80 in toluene solution as membrane phase,0.50~2.0 mol/L HCl as inner phase,rare earth ion solutions with pH 3.5~5.0 as outer phase.Ac- cording to the differences of transport behavior for rare earth ions,it is possible to separate rare earth ions from mixed solutions of rare earth ions by this liquid membrane system.展开更多
Process intensification using liquid emulsion membranes (LEMs) for extraction of copper has been studied in this work. In LEM process the extraction and stripping processes are combined in one stage. The solubility of...Process intensification using liquid emulsion membranes (LEMs) for extraction of copper has been studied in this work. In LEM process the extraction and stripping processes are combined in one stage. The solubility of the solute or the chemical affinity between the solute and carrier reagent in the membrane results in the separation of the solute from the feed mixture. In this work the membrane phase comprised of LIX 664N as the extractant dissolved in kerosene and Span 80 as surfactant. The stripping phase was sulfuric acid with 180 g/l concentration and feed phase had copper concentration of 3.5 g/l. Effect of various process parameters such as batch contact time, speed of agitation, W:O ratio and treat ratio has been experimentally investigated to get better insight of the process. The maximum enrichment of copper in the internal phase obtained was 11.6 times with batch contact time of 10 minutes, agitation speed of 300 rpm and treat ratio of 6:1.展开更多
Production of 6-aminopenicillanic acid (6-APA) by hydrolysis using penicillin acylase (PA) was studied as a model of an enzymatic emulsion liquid membrane (ELM) process. The loss of PA activity was examined for variou...Production of 6-aminopenicillanic acid (6-APA) by hydrolysis using penicillin acylase (PA) was studied as a model of an enzymatic emulsion liquid membrane (ELM) process. The loss of PA activity was examined for various membrane compositions (organic solvent, surfactant, carrier). The effects of some experimental variables on the stability of emulsion were investigated. It was found that the choice of organic solvent greatly affected tilestability of the emulsion. Increasing the concentration of the carrier in the membrane phase increases the transfer rate of substrate and products but also has a destabilizing effect on the emulsion. The recovery of 6-APA obtained by a di-carrier system (N263-N1923) was much higher than those when either of the di-carriers was used separately.The whole process was controlled both by the enzymatic reaction rate and by the transfer rate of the substrate and the products, however, the ratio of them could be changed by varying the composition of the system. For an optimum condition, it was obtained that the recovery ratio of 6-APA was over 80% and the conversion of benzyl penicillin (PG) was up to 90% in the external phase after 30 minutes. Meanwhile, the breakage percentage of the emulsion was less than 2%.展开更多
The hollow fiber supported liquid membrane extraction was introduced to treat coal gasification wastewater to recover phenolic compounds,with tributyl phosphate (TBP) as carrier,kerosene as the membrane solvent,sodium...The hollow fiber supported liquid membrane extraction was introduced to treat coal gasification wastewater to recover phenolic compounds,with tributyl phosphate (TBP) as carrier,kerosene as the membrane solvent,sodium hydroxide solution as the stripping agent and PVDF as the membrane material. Factors having strong impact on the extraction efficiency were studied in detail,including the mass transfer mode,twophase flow rate,stripping phase concentration. As extraction system with 20% TBP-kerosene,parallel flow mass transfer,stripping phase concentration 0.1 mol/L,the optimal operating conditions could be obtained. Under the optimum operating conditions,the time required to reach equilibrium for the extraction is 50 min, and extraction efficiency of phenol is 86. 2% and the phenol concentration of effluent is 98.64 mg/L.展开更多
The extraction of palladium from hydrochloric acid solutions into emulsion liquid membranes (ELMs) using LIX 984N-C as the extractant was investigated. The influential factors and the total capacities of palladium ext...The extraction of palladium from hydrochloric acid solutions into emulsion liquid membranes (ELMs) using LIX 984N-C as the extractant was investigated. The influential factors and the total capacities of palladium extraction were determined by a batch method. The behavior of palladium extraction by ELMs under the operational conditions-pH of the external feed phase, surfactant and extractant concentration, internal stripping phase concentration, treat ratio and agitation speed were reported. Using LIX 984N-C, palladium was effectively extracted from the external acidic chloride feed phase into the internal receiving phase of W/O emulsions. More than 92% of palladium could be extracted at a feed pH of 2 with 3% Span 80, 9% LIX 984N-C and 7M HCl at a stirring speed of 300 rpm.展开更多
The extraction of copper from acidic medium using Liquid Emulsion Membrane LEM as contactors was studied. b diketone LIX 54 as an extractant ,sesqueoleate which is nonionic surfactant with HLB value 3.7 and 0.1 M H2SO...The extraction of copper from acidic medium using Liquid Emulsion Membrane LEM as contactors was studied. b diketone LIX 54 as an extractant ,sesqueoleate which is nonionic surfactant with HLB value 3.7 and 0.1 M H2SO4 as stripping solution were used. The influence of initial concentration of copper in the aqueous feed phase, pH of external and internal aqueous phase, stirring speed, and concentration of extractant on the extraction rate was examined. The results obtained showed that practically all the copper content was removed from the acidic feed solution. The recovery of copper attained 96–100% and concentration ratios of about 40-fold could be achieved.展开更多
The emulsion liquid membrane technique was used to extract amino-J acid from industrial dye waste-water.The effects of stirring speed,ratio of the emulsion to water(Rew),ratio of the oil to internal phase(Roi)and memb...The emulsion liquid membrane technique was used to extract amino-J acid from industrial dye waste-water.The effects of stirring speed,ratio of the emulsion to water(Rew),ratio of the oil to internal phase(Roi)and membrane phase components on the extraction rate were investigated and optimized.The results showed that the extraction rate of amino-J acid approached 97% when the stirring speed was 300 r/min,Rew 1:6,Roi 1:1,trioctylamine(TOA)3 mL/100 mL kerosene,and methyl?didecyle?alcohol?acrylate(LMA-2)3 g/100 mL kerosene,respectively.The extraction rate had not changed with the oil phase reused for times.展开更多
A non-dispersive extraction technique, using an emulsion liquid membrane within a hollow-fiber-contactor for the extraction and enrichment of Nd^3+ from the dilute feed aqueous, was applied. The emulsion system is co...A non-dispersive extraction technique, using an emulsion liquid membrane within a hollow-fiber-contactor for the extraction and enrichment of Nd^3+ from the dilute feed aqueous, was applied. The emulsion system is consisted of span80 [ sorbitian monooleate], paraffin oil, D2EHPA [ 2-( 2-ethylhexyl- phosphonic acid)], kerosene as well as HCl solution. The extraction under various conditions such as the span80 concentrations, the flow rate of aqueous, the extraction time and HCl concentrations in receiving phase were studied. Results show that the lower the flow rates of aqueous are, the higher the extraction percentage and enrichment-fold are, and the extraction percentage increases with the increasing of HCl concentrations. When the initial Nd^3+ concentration in feed is maintained at 1000 mg· L^-1 and the emulsion is recycled with 70 times by a counter-flow,展开更多
The investigation of recovery Ga 3+ by emulsion liquid membrane (ELM) using Tri alkyl oxide phosphine (TRPO) as the mobile carrier was reported. The optimum emulsion liquid membrane conditions were determinated....The investigation of recovery Ga 3+ by emulsion liquid membrane (ELM) using Tri alkyl oxide phosphine (TRPO) as the mobile carrier was reported. The optimum emulsion liquid membrane conditions were determinated. They were: the feed pH 1.0, organic phase consisting of 5% TRPO, 4% LMS 2 and 2% liquid paraffin in kerosene solution, 10% K 4[Fe(CN) 6] aq. solution as the stripping agent, R oi =2∶1, R ew =1∶5. At the optimum ELM operating condition, the recovery rate of gallium was 96.5%, and the oil phase can be reused for 5 times.展开更多
The instability mechanisms of the supported liquid membrane using Celgard 2500 membranes as support and tributyl phosphate dissolved in kerosene as carrier for phenol transport was studied by electrochemical impedance...The instability mechanisms of the supported liquid membrane using Celgard 2500 membranes as support and tributyl phosphate dissolved in kerosene as carrier for phenol transport was studied by electrochemical impedance spectroscopy.Emulsion formation is demonstrated to be one of the main causes for the instability of supported liquid membrane in the present system.The emulsion-facilitated conditions,such as higher membrane liquid concentration,faster stirring speed,lower salt concentration and higher HLB value,would accelerate the degradation of supported liquid membrane.Other mechanisms including solubility and osmotic pressure work together to increase the membrane liquid loss.展开更多
Introduction Since it was discovered in 1968,liquid membrane separation technique has been widely studied,particularly in separating or recovering some metal ions.It is a novel study that trace substances in analytica...Introduction Since it was discovered in 1968,liquid membrane separation technique has been widely studied,particularly in separating or recovering some metal ions.It is a novel study that trace substances in analytical chemistry are enriched by liquid membrane.There have been few reports on enriching cerium by emulsion liquid membrane (ELM) now.Therefore,authors studied the liquid membrane methed for enriching trace cerium.The sensibility measuring cerium by spectrophotometry was increased greatly.展开更多
Zn containing waste water from a viscose staple fiber plant has been treated using the emulsion liquid membrane (ELM) process since 1995. The flow sheet and operating parameters of the ELM process are introduced. A...Zn containing waste water from a viscose staple fiber plant has been treated using the emulsion liquid membrane (ELM) process since 1995. The flow sheet and operating parameters of the ELM process are introduced. After adjusting the membrane composition, changing the emulsion phase ratio, and adding a scrubbing step, the ELM process operated normally without trouble for emulsion splitting and mass transport throughput. The splitter voltage was decreased to 3.55 kV. The zinc concentration of treated waste water was lowered to less than 10 mg·L -1 . More than 95% of the zinc was recovered and reused.展开更多
文摘The aim of this study was to design a new emulsion liquid membrane(ELM)system for the separation of succinic acid from aqueous solutions.The concentration of succinic acid varied from 20 to 60 mmol·L^(-1).The prepared ELM system includes tributylamine(TBA)as a carrier,commercial kerosene as a solvent,Span 80 as a surfactant,and Na2CO3as a stripping agent.In order to control the membrane swelling,different values of cyclohexanone were added to the membrane phase.The effect of various empirical variables on the extraction of the succinic acid such as acid concentration in the feed solution,initial feed concentration,carrier concentration,the stirring speed of the extraction,Na2CO3,surfactant,and cyclohexanone concentrations,and treat ratio in the ELM system.The best result was obtained when TBA was used as the carrier.The final acid extraction efficiency was independent of pH variations of the aqueous feed solution.The extraction of succinic acid solution with a concentration of 40 mmol·L^(-1)was improved by increasing the treat ratio 1:7-1:3,stripping phase concentration 0.5-1.5 mol·L^(-1),stirring speed 300-500 r·min^(-1)and cyclohexanone concentration in the membrane phase 1.2-1.6 mol·L^(-1).No considerable effect on the extraction rate was observed for the carrier concentration in the membrane phase.But,the surfactant concentration in the feed phase showed a dual effect on the extraction efficiency.
基金Supported by the Ministry of Higher Education(MOHE)Universiti Teknologi Malaysia(RU Research GrantGUP:Q.J130000.2546.12H50)
文摘Phenol is considered as pollutant due to its toxicity and carcinogenic effect.Thus,variety of innovative methods for separation and recovery of phenolic compounds is developed in order to remove the unwanted phenol from wastewater and obtain valuable phenolic compound.One of potential method is extraction using green based liquid organic solvent.Therefore,the feasibility of using palm oil was investigated.In this research,palm oil based organic phase was used as diluents to treat a simulated wastewater containing 300×10^(-6) of phenol solution using emulsion liquid membrane process(ELM).The stability of water-in-oil(W/O) emulsion on diluent composition and the parameters affecting the phenol removal efficiency and stability of the emulsion;such as emulsification speed,emulsification time,agitation speed,surfactant concentration,pH of external phase,contact time,stripping agent concentration and treat ratio were carried out.The results of ELM study showed that at ratio7 to 3 of palm oil to kerosene,5 min and 1300 r·min^(-1) of emulsification process the stabile primary emulsion were formed.Also,no carrier is needed to facilitate the phenol extraction.In experimental conditions of500 r·min^(-1) of agitation speed,3%Span 80,pH 8 of external phase,5 min of contact time,0.1 mol·L^(-1) NaOH as stripping agent and 1:10 of treat ratio,the ELM process was very promising for removing the phenol from the wastewater.The extraction performance at about 83%of phenol was removed for simulated wastewater and an enrichment of phenol in recovery phase as phenolate compound was around 11 times.
基金Supported by the National Natural Science Foundation of China (20676023)
文摘Recovery of copper ions from wastewater using a hollow fiber supported emulsion liquid membrane (HFSELM) was studied with LIX984N as carrier, kerosene as diluents, and sulfuric acid solution as stripping phase. Effects of compositions of feed and emulsion liquid phase, flow rates on both sides of membrane, and hollow fiber module parameters were investigated. The stability of the emulsion liquid phase without surfactant and the effect of buffer in the feed phase on the extraction rate were also evaluated. It is found that the stability of the emulsion phase without surfactant is poor. Higher flow velocity gives shorter residence time for the emulsion liquid phase on the tube side, reducing the effect of particle coalescence on the separation process. The extraction rate increases with the increase of feed phase pH, carrier concentration, hydrogen ion concentration in the stripping phase, and ef- fective hollow fiber area. The phase ratio in the emulsion liquid phase has a negative effect on extraction rate. The flow rates on both sides have little influence on the extraction performance of the HFSELM, while buffer addition in the feed solution improves the extraction efficiency.
文摘Permeation of Cu(Ⅱ) from its aqueous solution through a supported liquid membrane (SLM) containing di(2-ethylhexyl)phosphoric acid (D2EHPA) carrier dissolved in coconut oil has been studied. The effects of Cu(Ⅱ), pH (in feed), H2SO4 (stripping) and D2EHPA (in membrane) concentrations have been investigated. The stability of the D2EHPA-coconut oil has also been evaluated. High Cu(Ⅱ) concentration in the feed leads to an increase in flux from 4.1 × 10^-9 to 8.9 × 10^-9 mol/(m^2·s) within the Cu(Ⅱ) concentration range 7.8×10^-4-78.6×10^-4 mol/L at pH of 4.0 in the feed and 12.4 × 10^-4 mol/L D2EHPA in the membrane phase. Increase in H2SO4 concentration in strip solution leads to an increase in copper ions flux up to 0.25 mol/L H2SO4, providing a maximum flux of 7.4 × 10^-9 mol/(m^2·s). The optimum conditions for Cu(Ⅱ) transport are, pH of feed 4.0, 0.25 mol/L H2SO4 in strip phase and 12.4 × 10^-4 mol/L D2EHPA (membrane) in 0.5 μm pore size polytetrafluoroethylene (PTFE) membrane. It has been observed that Cu(Ⅱ) flux across the membrane tends to increase with the concentration of copper ions. Application of the method developed to copper plating bath rinse solutions has been found to be successful in the recovery of Cu(Ⅱ).
基金Supported by the National Natural Science Foundation of China
文摘It is indicated from a study of transport of rare earth ions through the emulsion liquid mem- brane of bis(2,4,4-trimethylpentyl)phosphinic acid-Span 80-toluene that transporting rare earth ions com- pletely and rapidly was realized under the optimum experimental conditions:1.0×10^(-3)~3.0×10^(-3)mol/L bis(2,4,4-trimethylpentyl)phosphinic acid and 2%~4%(W/V)Span 80 in toluene solution as membrane phase,0.50~2.0 mol/L HCl as inner phase,rare earth ion solutions with pH 3.5~5.0 as outer phase.Ac- cording to the differences of transport behavior for rare earth ions,it is possible to separate rare earth ions from mixed solutions of rare earth ions by this liquid membrane system.
文摘Process intensification using liquid emulsion membranes (LEMs) for extraction of copper has been studied in this work. In LEM process the extraction and stripping processes are combined in one stage. The solubility of the solute or the chemical affinity between the solute and carrier reagent in the membrane results in the separation of the solute from the feed mixture. In this work the membrane phase comprised of LIX 664N as the extractant dissolved in kerosene and Span 80 as surfactant. The stripping phase was sulfuric acid with 180 g/l concentration and feed phase had copper concentration of 3.5 g/l. Effect of various process parameters such as batch contact time, speed of agitation, W:O ratio and treat ratio has been experimentally investigated to get better insight of the process. The maximum enrichment of copper in the internal phase obtained was 11.6 times with batch contact time of 10 minutes, agitation speed of 300 rpm and treat ratio of 6:1.
基金the National Natural Science Foundation of China (No. 29136130).
文摘Production of 6-aminopenicillanic acid (6-APA) by hydrolysis using penicillin acylase (PA) was studied as a model of an enzymatic emulsion liquid membrane (ELM) process. The loss of PA activity was examined for various membrane compositions (organic solvent, surfactant, carrier). The effects of some experimental variables on the stability of emulsion were investigated. It was found that the choice of organic solvent greatly affected tilestability of the emulsion. Increasing the concentration of the carrier in the membrane phase increases the transfer rate of substrate and products but also has a destabilizing effect on the emulsion. The recovery of 6-APA obtained by a di-carrier system (N263-N1923) was much higher than those when either of the di-carriers was used separately.The whole process was controlled both by the enzymatic reaction rate and by the transfer rate of the substrate and the products, however, the ratio of them could be changed by varying the composition of the system. For an optimum condition, it was obtained that the recovery ratio of 6-APA was over 80% and the conversion of benzyl penicillin (PG) was up to 90% in the external phase after 30 minutes. Meanwhile, the breakage percentage of the emulsion was less than 2%.
文摘The hollow fiber supported liquid membrane extraction was introduced to treat coal gasification wastewater to recover phenolic compounds,with tributyl phosphate (TBP) as carrier,kerosene as the membrane solvent,sodium hydroxide solution as the stripping agent and PVDF as the membrane material. Factors having strong impact on the extraction efficiency were studied in detail,including the mass transfer mode,twophase flow rate,stripping phase concentration. As extraction system with 20% TBP-kerosene,parallel flow mass transfer,stripping phase concentration 0.1 mol/L,the optimal operating conditions could be obtained. Under the optimum operating conditions,the time required to reach equilibrium for the extraction is 50 min, and extraction efficiency of phenol is 86. 2% and the phenol concentration of effluent is 98.64 mg/L.
文摘The extraction of palladium from hydrochloric acid solutions into emulsion liquid membranes (ELMs) using LIX 984N-C as the extractant was investigated. The influential factors and the total capacities of palladium extraction were determined by a batch method. The behavior of palladium extraction by ELMs under the operational conditions-pH of the external feed phase, surfactant and extractant concentration, internal stripping phase concentration, treat ratio and agitation speed were reported. Using LIX 984N-C, palladium was effectively extracted from the external acidic chloride feed phase into the internal receiving phase of W/O emulsions. More than 92% of palladium could be extracted at a feed pH of 2 with 3% Span 80, 9% LIX 984N-C and 7M HCl at a stirring speed of 300 rpm.
文摘The extraction of copper from acidic medium using Liquid Emulsion Membrane LEM as contactors was studied. b diketone LIX 54 as an extractant ,sesqueoleate which is nonionic surfactant with HLB value 3.7 and 0.1 M H2SO4 as stripping solution were used. The influence of initial concentration of copper in the aqueous feed phase, pH of external and internal aqueous phase, stirring speed, and concentration of extractant on the extraction rate was examined. The results obtained showed that practically all the copper content was removed from the acidic feed solution. The recovery of copper attained 96–100% and concentration ratios of about 40-fold could be achieved.
文摘The emulsion liquid membrane technique was used to extract amino-J acid from industrial dye waste-water.The effects of stirring speed,ratio of the emulsion to water(Rew),ratio of the oil to internal phase(Roi)and membrane phase components on the extraction rate were investigated and optimized.The results showed that the extraction rate of amino-J acid approached 97% when the stirring speed was 300 r/min,Rew 1:6,Roi 1:1,trioctylamine(TOA)3 mL/100 mL kerosene,and methyl?didecyle?alcohol?acrylate(LMA-2)3 g/100 mL kerosene,respectively.The extraction rate had not changed with the oil phase reused for times.
文摘A non-dispersive extraction technique, using an emulsion liquid membrane within a hollow-fiber-contactor for the extraction and enrichment of Nd^3+ from the dilute feed aqueous, was applied. The emulsion system is consisted of span80 [ sorbitian monooleate], paraffin oil, D2EHPA [ 2-( 2-ethylhexyl- phosphonic acid)], kerosene as well as HCl solution. The extraction under various conditions such as the span80 concentrations, the flow rate of aqueous, the extraction time and HCl concentrations in receiving phase were studied. Results show that the lower the flow rates of aqueous are, the higher the extraction percentage and enrichment-fold are, and the extraction percentage increases with the increasing of HCl concentrations. When the initial Nd^3+ concentration in feed is maintained at 1000 mg· L^-1 and the emulsion is recycled with 70 times by a counter-flow,
文摘The investigation of recovery Ga 3+ by emulsion liquid membrane (ELM) using Tri alkyl oxide phosphine (TRPO) as the mobile carrier was reported. The optimum emulsion liquid membrane conditions were determinated. They were: the feed pH 1.0, organic phase consisting of 5% TRPO, 4% LMS 2 and 2% liquid paraffin in kerosene solution, 10% K 4[Fe(CN) 6] aq. solution as the stripping agent, R oi =2∶1, R ew =1∶5. At the optimum ELM operating condition, the recovery rate of gallium was 96.5%, and the oil phase can be reused for 5 times.
基金Supported by the National Natural Science Foundation of China (20676023).
文摘The instability mechanisms of the supported liquid membrane using Celgard 2500 membranes as support and tributyl phosphate dissolved in kerosene as carrier for phenol transport was studied by electrochemical impedance spectroscopy.Emulsion formation is demonstrated to be one of the main causes for the instability of supported liquid membrane in the present system.The emulsion-facilitated conditions,such as higher membrane liquid concentration,faster stirring speed,lower salt concentration and higher HLB value,would accelerate the degradation of supported liquid membrane.Other mechanisms including solubility and osmotic pressure work together to increase the membrane liquid loss.
文摘Introduction Since it was discovered in 1968,liquid membrane separation technique has been widely studied,particularly in separating or recovering some metal ions.It is a novel study that trace substances in analytical chemistry are enriched by liquid membrane.There have been few reports on enriching cerium by emulsion liquid membrane (ELM) now.Therefore,authors studied the liquid membrane methed for enriching trace cerium.The sensibility measuring cerium by spectrophotometry was increased greatly.
文摘Zn containing waste water from a viscose staple fiber plant has been treated using the emulsion liquid membrane (ELM) process since 1995. The flow sheet and operating parameters of the ELM process are introduced. After adjusting the membrane composition, changing the emulsion phase ratio, and adding a scrubbing step, the ELM process operated normally without trouble for emulsion splitting and mass transport throughput. The splitter voltage was decreased to 3.55 kV. The zinc concentration of treated waste water was lowered to less than 10 mg·L -1 . More than 95% of the zinc was recovered and reused.