Removal of copper ions from a waste mine water by a liquid emulsion membrane method (original) (raw)
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Liquid membrane emulsion process for recovering the copper content of a mine drainage
2009
A study of the treatment of an acidic mine drainage to extract its Cu(II) content by emulsion liquid membranes is made. Copper was removed using 5-nonylsalicylaldoxime (LIX-860 N-IC) dissolved in aviation kerosene. The effects of various factors, such as pH and metal content in the feed solution, carrier concentration and surfactant content in the membrane, acidity of the stripping solution, and stirring speed to prepare the primary and the double emulsion, are reviewed. The experimental data were analyzed in terms of a metal transport mechanism based on a facilitated transport model, which takes account the chemical reaction between the metal and the oximic extractant and the diffusion processes in the aqueous phase close to the external interface of membrane.
Minerals Engineering, 2017
Process water from mineral processing plants may contain a significant amount of dissolved metal ions, which may be recycled as process water, or discharged into the environment as effluent. If they are discharged into the environment they may cause significant problems for the local flora and fauna. One method of removing metal ions from aqueous systems, which has generated considerable interest over recent years, is the emulsion liquid membrane (ELM) technique, which incorporates solvent extraction and stripping. This work details the use of design of experiments applied to an ELM process for removing copper ions from a dilute aqueous solution. Initially, a fractional factorial design was used to screen out the most important factors; this was followed by a central composite design to obtain optimal operating conditions. The extraction percentage of copper was obtained as more than 99% under these conditions.
— In the present work the process of extraction of cadmium, copper, zinc, and iron metal ions was studied using Emulsion Liquid Membrane (ELM) technique. Emulsion liquid membrane system depends on the preparation primary water-in-oil emulsion then emulsified the primary emulsion in water to produce double water-in-oil-in-water emulsion. Therefore three liquid phases will occurs: internal (receiving) phase, liquid membrane phase, and external phase. The internal and external phases are miscible with each other but separated by the membrane phase which is immiscible with both. The membrane was prepared by dissolving the extractant D2EHPA (di-2-ethylhexylphosphoric acid) used as a mobile carrier, and sodium dodecyl sulphonate, a surfactant, in kerosene. The internal (receiving) phase was prepared by dissolving sulfuric acid in water. The effect of variables: initial concentration of metal ions in the feed phase, surfactant concentration, carrier concentration, sulfuric acid concentration in the receiving (internal) phase, agitation time, volume ratio of the external feed phase to the primary water-in-oil emulsion, and pH of feed were studied on the percentage removed of metal ions in experiments carried out in a batch-type stirred vessel at 30 o C. The results showed that the percent removed of metal ions was in general increase with increasing of surfactant concentration, carrier concentration, sulfuric acid concentration in the internal phase, agitation time, and pH of feed and decrease with the volume ratio of the external feed phase to the primary water-in-oil emulsion. The results show that it is possible to recover 98 % of metal ions mixture.
Jordanian Journal of Engineering and Chemical Industries, 2021
This work aims to optimize the parameters that affect the stability of a W/O emulsion to exploit it in the extraction of heavy metals contained in the liquid effluents. The study of the emulsion stability shows that; an emulsification time of 10 minutes, a surfactant concentration of Span80 equal to 3% (w/w), an extractant concentration of Triethylamine N(CH2CH3)3 equal to 5% (w/w), an internal phase concentration of phosphoric acid (H3PO4) of 0.75M, a volume ratio of membrane phase to internal phase of 1, a volume ratio of external phase to the emulsion of 20 and a stirring speed of 180 rpm; lead to the formation of a very stable emulsion with a very low rupture rate of around 1.92% after one hour of contact time. The results of extraction of copper ions revealed that under the best operational conditions, the extraction yield was closed to 93.33% for 20% extractant content, a contact time of 12 minutes, and an initial concentration of copper ions of 400 ppm. The application of this new membrane matrix based on phosphoric acid used as inner phase, sorbitan monooleate as a surfactant, and Triethylamine as extractant has been proven effective for extracting copper ions in water.
REMOVAL OF HEAVY METAL FROM AQUEOUS WASTEWATER BY EMULSION LIQUID MEMBRANE
Extraction and recovery of heavy metal from waste water using Liquid Membrane technology is more efficient than methods such as precipitation that form sludge that needs to be disposed in landfills. A green emulsion liquid membrane (ELM) has been formulated in this work using an environmental-friendly refined palm oil as the main diluent of ELM to recover zinc ions from aqueous waste solution using di-(2-ethylhexyl) phosphoric acid (D2EHPA) as a highly selective carrier with double Water-Oil-Water emulsion. This system promotes many advantages including simple operation, high selectivity, low energy requirement, and single stage extraction and stripping process. In this study ELM process was used to transport zinc metal ion from aqueous feed phase to stripping phase which was prepared by using H2SO4, HCl, and HNO3. This extraction was done in a Batch-type stirred tank at room temperature with different types of vegetable oils green solvent. For green ELM process the various vegetable oils have been studied as diluents, such as palm oil, sesame oil, coconut oil, soyabean oil and for further studies we found that palm oil is more effective vegetable oil which gives more recovery of zinc ion from wastewater. The effect of various parameters such as, pH of the feed solution, concentration of the stripping phase, surfactant concentration, carrier concentration, F/M phase ratio, O/I phase ratio, contact time of the double emulsion etc. were studied. After determining the optimum conditions it was possible to extract zinc metal ion up to 62% from aqueous feed phase in a single stage extraction.
Separation and Purification Technology, 2000
Emulsion Liquid Membrane (ELM) is a separation technique, which requires organic solvent, extractant and surfactant for its formulation. All the components play important roles. Surfactant adds stability to the emulsion but at higher concentration lowers extraction rate. Some surfactants, known as bi-functional surfactants, have dual properties of an extractant and an emulsifier. Use of such surfactant may eliminate the addition of an extractant to ELM system. In this study, polyethylene glycol was used as bi-functional surfactant in an ELM process for the extraction of metal ions from a ternary (copper, nickel and cobalt) aqueous solution. Dichloroethane, ammonium thiocyanate and potassium hydroxide were used as solvent, ligand and stripping agent, respectively. The paper presents the results on the characterization of the reactions (stoichiometry and reaction order) obtained through equilibrium and kinetic studies along with some batch emulsion extraction results.
Journal of the Brazilian Chemical Society, 2006
Foi estudada a extração de íons cádmio(II) a partir de soluções aquosas ácidas, usando, em uma cela de transferência sob agitação, uma membrana líquida em emulsão, (MLE) preparada pela mistura de querosene com D2EHPA (um ácido alquilfosfórico) como carregador móvel e Span-80 como surfactante. A membrana MLE permitiu transporte eficiente do metal, da solução de alimentação para o extrato de coleta em experimentos realizados a 25 ºC. As variáveis significativas no transporte de cádmio através da membrana foram a concentração do extrator e a quantidade de metal na solução alimentadora. A concentração de HCl como agente de coleta afetou somente a taxa inicial de extração do metal, mas não a extensão da extração. A quantidade de surfactante usada neste estudo estabilizou a membrana adequadamente, mas o uso de uma quantidade maior produziu uma menor taxa de extração inicial devido à resistência inferfacial mais alta. Os resultados experimentais sugerem a possibilidade de recuperação ou remoção de metais tóxicos de soluções aquosas diluídas em um extrator baseado em membranas líquidas emulsificadas. It is studied the extraction of cadmium(II) ions from acidic aqueous solutions using a stirred transfer cell-type emulsion liquid membrane (ELM) prepared by dissolving in kerosene, with D2EHPA (an alkylphosphoric acid) as mobile carrier and Span-80 as surfactant. The ELM allowed efficient metal transport from the feed solution to the stripping liquor in experiments carried out at 25 ºC. The significant variables on cadmium transport through the membrane were extractant concentration and metal content in the feed metal-donor solution. Concentration of HCl as stripping agent affected only the initial metal extraction rate but not the extraction extent. The surfactant content used in this study stabilized the membrane adequately, but the use of a higher content produced a smaller initial extraction rate due to higher interfacial resistance. The experimental results suggest the possibility of recovering or removing valuable or toxic metals from dilute aqueous solution in an extractor based on emulsified liquid membranes.
Ultrasonics Sonochemistry, 2010
The aim of this work was to study the emulsification assisted by ultrasonic probe (22.5 kHz) and investigate the removal of copper(II) ions from aqueous solution using water-in-oil-in-water (W/O/W) emulsion liquid membrane process (ELM). The membrane was prepared by dissolving the extractant bis(2-ethylhexyl)phosphoric acid (D2EHPA) and the hydrophobic surfactant sorbitan monooleate (Span 80) in hexane (diluent). The internal phase consisted of an aqueous solution of sulfuric acid. Effects of operating parameters such as emulsification time, ultrasonic power, probe position, stirring speed, carrier (D2EHPA) and surfactant (Span 80) concentrations volume ratios of organic phase to internal striping phase and of external aqueous phase to membrane (W/O) phase, internal phase concentration and choice of diluent on the membrane stability were studied. With ultrasound, the W/O emulsion lifetime were much higher than those reported previously by mechanical agitation. The effect of carrier and Cu(II) initial concentration on the extraction kinetics was also investigated. Nearly all of the Cu(II) ions present in the continuous phase was extracted within a few minutes. Additionally, the influence of H 2 SO 4 concentration on the stripping efficiency was examined.
A New Emulsion Liquid Membrane Based on a Palm Oil for the Extraction of Heavy Metals
Membranes, 2015
The extraction efficiency of hexavalent chromium, Cr(VI), from water has been investigated using a vegetable oil based emulsion liquid membrane (ELM) technique. The main purpose of this study was to create a novel ELM formulation by choosing a more environmentally friendly and non-toxic diluent such as palm oil. The membrane phase so formulated includes the mobile carrier tri-n-octylmethylammonium chloride (TOMAC), to facilitate the metal transport, and the hydrophilic surfactant Tween 80 to facilitate the dispersion of the ELM phase in the aqueous solution. Span 80 is used as surfactant and butanol as co-surfactant. Our results demonstrate that this novel ELM formulation, using the vegetable palm oil as diluent, is useful for the removal of hexavalent chromium with an efficiency of over 99% and is thus competitive with the already existing, yet less environmentally friendly, ELM formulations. This result was achieved with an optimal concentration of 0.1 M NaOH as stripping agent and an external phase pH of 0.5. Different water qualities have also been investigated showing that the type of water (deionized, distilled, or tap water) does not significantly influence the extraction rate.
Copper removal from effluents by various separation techniques
Hydrometallurgy, 2004
In this study, the recovery of copper ions from simulated and real wastewaters of a mine and minerals processing plant was investigated. The separation process employed was flotation, which was applied in three different mechanisms: (i) ion flotation using xanthates, (ii) precipitate flotation generating copper hydroxide and (iii) sorptive flotation using zeolites as sorbent material. Under the studied conditions, ion and sorptive flotation were found to be effective methods for copper removal with almost 100% Cu removal achieved, while the precipitation method failed. The copper removal was always higher in simulated mixture than in real effluents; it may be due to the presence of other minor constituents that they have not taken into account in simulated mixture (e.g. organic compounds). The bubble generation method was that of dispersedair flotation. Reference is also given to economic aspects. An economic study of sorptive flotation showed that the capital investment for a 10 m 3 /h plant would be of the order of US$1.15 million dollars. The operating costs are about US$1.76 million per year. The total revenues from water recycling and reuse are US$68,800 per annum, without calculating the benefits of copper recovery. D