The use of the emulsion liquid membrane technique to remove copper ions from aqueous systems using statistical experimental design (original) (raw)
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Removal of copper ions from a waste mine water by a liquid emulsion membrane method
Minerals Engineering, 2005
This is a communication on the removal of copper(II) ions from a residual mine water using an emulsified liquid membrane (ELM). The membrane was prepared by dissolving the extractant LIX-860 (a salicylaldoxime), used as a mobile carrier, and Span-80, a surfactant, in kerosene. The ELM allowed an efficient metal transport from the feed solution towards the strip liquor, in experiments carried out in a batch-type stirred tank at 30°C. A screening factor-type experimental statistical design was developed, which established the variables and their interrelation affecting the studied process. The experimental results and the variance analysis indicated that the statistically significant variables on copper transport through the membrane were the extractant concentration, the stirring time and the stirring speed of the double emulsion. The surfactant concentration range employed in this study adequately stabilized the membrane. However, it did not produce any positive effect on metal extraction. It was observed that the use of an excessively high content of surfactant produced lower metal transport extraction since it gave rise to a higher interfacial resistance. The experimental results reported show the potential for removal of valuable or toxic metals from dilute mine solutions using an extractor based on emulsified liquid membranes.
The Canadian Journal of Chemical Engineering, 2018
The emulsion liquid membrane technique was utilized to selectively extract copper and nickel from a synthetic aqueous solution containing calcium, which was used to mimic a tailings stream found in the Sudbury region of Canada. The results showed copper and nickel ions were successively extracted from the synthetic solution. Two central composite designs and an analysis of the experiments were used to optimize the process and determine the main effects and interactions of experimental factors. In the first stage, copper was extracted with a minimum removal of nickel and calcium. It was found that under optimum conditions 98 % of the copper was extracted, with only 0.9 % of the nickel and 1.3 % of the calcium being extracted. The subsequent copper stripping efficiency was 95.7 %. In the second stage, the remaining aqueous solution was treated to remove nickel with minimum calcium removal. During this stage, the corresponding nickel and calcium removal percentages were 99.0 and 0.55 %, respectively, with a nickel stripping efficiency of 84.1 %. Laboratory bench-scale tests using a two-stage mixer-settler showed a good correlation with these results when moving to a semi-continuous process, which extracted 99.7 % of the copper and 98.2 % of the nickel, with only 2.2 % calcium extraction.
— 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.
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.
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.
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
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.
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.
Modeling of metal ion removal from wastewater by electrodialysis
Separation and Purification Technology, 2005
This paper describes a robust design method for separation of zinc ions from a solution using a laboratory electrodialysis (ED) setup. An experimental investigation is presented to determine the optimum configuration of factors for the best performance. In order to optimize the performance, the factors which have the greatest influence have to be identified and their optimum values chosen. In this research, Taguchi method was used initially to plan a minimum number of experiments. An orthogonal array of experiments was used to allow simultaneous variation of several factors and investigation of interactions between them. An L 9 orthogonal array (four factors in three levels) was employed to evaluate the effects of factors on response. Ionics membranes with moderate ion exchange capacities were used. The optimal levels determined for the four influential factors are: concentration 1000 ppm, temperature 60 °C, flow rate 0.07 mL/s and voltage 30 V. Comparing results obtained by Asahi glass membranes with those obtained by Ionics membranes, it was found that using a membrane pair with higher Ion Exchange Capacity (IEC) improves the performance. The highest removal percentage was found to be 97.67% and 98.73% for the two types of membranes. Statistical analysis, ANOVA, was then employed to determine the relationship between the experimental conditions and the yield levels.
Applied Sciences, 2021
Heavy metal contamination in water is a major health concern, directly related to rapid growth in industrialization, urbanization, and modernization in agriculture. Keeping this in view, the present study has attempted to develop models for the process optimization of nanofiltration (NF) membrane and electrocoagulation (EC) processes for the removal of copper, nickel, and zinc from an aqueous solution, employing the response surface methodology (RSM). The variable factors were feed concentration, temperature, pH, and pressure for the NF membrane process; and time, solution pH, feed concentration, and current for the EC process, respectively. The central composite design (CCD), the most commonly used fractional factorial design, was employed to plan the experiments. RSM models were statistically analyzed using analysis of variance (ANOVA). For the NF membrane, the rejection of Zn, Ni, and Cu was observed as 98.64%, 90.54%, and 99.79% respectively; while the removal of these through t...