Initial Feed Phase Concentration Research Articles

Removal of Acetaminophen Residues from Wastewater by Bulk Liquid Membrane Process

The removal of Anit-Inflammatory drugs, namely; Acetaminophen (ACTP), from wastewater by bulk liquid membrane (BLM) process using Aliquat 336 (QCl) as a carrier was investigated. The effects of several parameters on the extraction efficiency were studied in this research, such as the initial feed phase concentration (10-50) ppm of ACTP, stripping phase (NaCl) concentration (0.3,0.5,0.7 M), temperature (30-50oC), the volume ratio of feed phase to membrane phase (200-400ml/80ml), agitation speed of the feed phase (75-125 rpm), membrane stirring speed (0, 100, 150 rpm), carrier concentration (1, 5, 9 wt%), the pH of feed (2, 4, 6, 8, 10), and solvent type (CCl4 and n-Heptane). The study shows that high extraction efficiency for ACTP of about 97% was achieved by a bulk liquid membrane at 50 ppm initial concentration of feed; stirring speed of feed phase 130 rpm; stirring speed of membrane phase 100rpm; 0.5 M NaCl concentration; carrier concentration 1wt%; volume ratio of 200ml feed:80ml membrane; feed pH of ACTP is 6, and 50˚C. The transport kinetics was evaluated using a kinetic model with two consecutive first-order irreversible reactions. The kinetics of (ACTP) transport by bulk liquid membrane was investigated at the best experimental conditions. The activation energy values of the extraction and stripping processes were 1.733 and 1.826 kJ.mol−1. The activation energy confirms that the transport process from solutions is controlled by diffusion.

Experimental and modeling studies on Cd (II) ions extraction by emulsion liquid membrane using Triton X-100 as biodegradable surfactant

In the recent years, the Emulsion Liquid Membrane (ELM) is considered as an attractive effective and alternative technique for the removal of toxic heavy metals from various aqueous waste effluent streams. In this work, ELM method is used to remove cadmium ions from stream water. Emulsion liquid membrane consisted of kerosene as organic solvents; Triton X-100as stabilized biodegradable surfactant and di-(2-ethylhexyl) phosphoric acid(D2EHPA) as carrier or extractant. At a fixed temperature (20 °C) Cd (II) extraction yield, Y (%), quantifying the efficiency of the process, was considered as a function of three parameters: D2EHPA/Triton X-100 ratio ranging from 0.5 to 3.5, initial feed phase concentration between 300 and 500 ppm and feed phase pH from 5 to 9.The experimental of the process parameters was optimized using an empirical smoothing method. The results were represented on three-dimensional plots using the Box-Behnken design and the response surface methodology. It was indicated that the calculated values being in good agreement with experimental data that under the optimized conditions ([Cd] =500 ppm, V agitation = 200–300 rpm, t = 20 min and pH = 7.6), Cd (II) ions extraction was recorded more than 98% of efficiency.

A new method for estimation of the overall mass transfer coefficient in pertraction

The pertraction of benzoic acid was studied in an agitated bulk liquid membrane system. The simultaneous effect of the operational parameters such as initial feed phase concentration (cf0), bulk liquid membrane volume (VLM) as well as a molecular descriptor (MD) which represent the organic solvent is discussed. The response surface methodology with a full factorial design and multiple linear regression analysis was applied for the description of the dependence of benzoic acid fluxes on selected parameters and descriptors.It was experimentally confirmed that the response surface methodology enables the determination of the parameter which can be considered as the apparent overall mass transfer coefficient dependent on the volume of the liquid membrane and the liquid membrane solvent in the studied system.It was additionally found that the extended linear regression models with two and/or three factor interaction terms describe over 99.5% of the total variance between the maximum output fluxes of benzoic acid and selected variables. To evaluate the prediction accuracy of the empirical regression models, the standard validation procedures were carried out. For example, the highest prediction accuracy (over 99.5%) was achieved in the case of the models involving three variables (cf0 and VLM parameters and 3D Wiener index (W3D)), and additionally, two factor interaction terms (cf0×VLM, cf0×W3D,VLM×W3D).Alternatively, similar models with comparable prediction accuracy but exploiting the squared Moriguchi octanol–water partition coefficient (MLOGP2) or reciprocal hyper-detour index (Rww) can be formulated. However, in this case, the models involves three factors interaction term (cf0×VLM×MD).

A comparative study of experimental optimization and response surface methodology of Bi(III) extraction by emulsion organophosphorus liquid membrane

This paper considers a new approach in the study of bismuth extraction by di(2-ethylhexyl)phosphoric acid (D2EHPA) as an organophosphorus carrier. A comparative study on the optimization of process parameters of an emulsion organophosphorus liquid membrane (EOgLM) by experimental work and response surface methodology (RSM), according to a Box–Behnken design (BBD), was carried out. Emulsion stability was achieved by the TritonX-100 as biodegradable surfactant in a dichloromethane membrane. The transport of Bi(III) ions from the acidic nitrate medium was evaluated from yield of extraction as analytical response, and the optimum conditions were initially determined by optimizing one parameter at the time. The extraction of Bi(III) was found to be total. The comparison between the values, experimentally optimized and those RSM optimized, was accomplished by optimizing the following parameters: D2EHPA/TritonX-100 ratio, initial feed phase concentration and concentration of internal phase. The comparison showed that all the values were in good agreement and all interactions of the chosen variables are significant except for the internal phase concentration and initial feed phase concentration. It was observed that it is necessary to decrease the acidity of the stripping phase to make the Bi extraction by EOgLM process more efficient.

Performance evaluation of vanadium (IV) transport through supported ionic liquid membrane

Increasing use of vanadium in different industries including alloys and steel manufacturing, electrochemical coating and catalysts causes environmental concern about the toxic effluents. In the present research, the extraction of vanadium in supported ionic liquid membrane was studied. The effect of operational conditions on the process performance such as initial feed phase concentration, pH of the feed solution, pore size of the membrane support, type of ionic liquid charged on the support and stripping agent solution was investigated. Vanadium was effectively transported from the feed phase to the stripping phase of ammonia solution using the room temperature ionic liquid, tri-n-octyl methyl ammonium chloride (TOMAC) embedded in the support membrane. Selective transport of vanadium from its mixture with chromium ions was carried out applying TOMAC as carrier. It was also observed that addition of a slight amount of a second room temperature ionic liquid, 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl] imide [BMIM][NTF2], improved the vanadium extraction process considerably.

Emulsion liquid membranes for cadmium removal: Studies of extraction efficiency

Emulsion liquid membrane (ELM) process suffers from emulsion instability problem. So far, emulsion produced by mechanical methods such as stirrer and homogenizer has big size and high emulsion breakage. This paper discussed the application of emulsion produced by sonicator to extract cadmium in a batch ELM system. The emulsions consist of N,N-Dioctyl-1-octanamine (trioctylamine/TOA), nitrogen trihydride (ammonia/NH4OH), sorbitan monooleate (Span 80), and kerosene as carrier, stripping solution, emulsifying agent, and organic diluent, respectively. Effects of comprehensive parameters on extraction efficiency of Cd(II) such as emulsification time, extraction time, stirring speed, surfactant concentration, initial feed phase concentration, carrier concentration, volume ratio of the emulsion to feed phase, and pH of initial feed phase were evaluated. The results showed that extraction efficiencies of Cd(II) greater than 98% could be obtained under the following conditions: 15 minutes of emulsification time, 4 wt.% of Span 80 concentration, 4 wt.% of TOA concentration, 15 minutes of extraction time, 250 rpm of stirring speed, 100 ppm of initial feed concentration, volume ratio of emulsion to feed phase of 1:5, and initial feed pH of 1.53.

The Separation of Aromatic Hydrocarbons Through a Supported Ionic Liquid Membrane

Ionic liquids can be considered as environmentally friendly solvents because of their low vapor pressures. Room-temperature ionic liquids are used as a supported liquid membrane for separation of aromatic from aliphatic. Aromatic hydrocarbons, benzene, toluene, ethylbenzene, and p-xylene are successfully transported through the polypropylene supported ionic liquid membrane based on 1-methyl-3-octyl imidazolium chloride. The separation performances, represented by the percentage extraction and separation factor, are analyzed systematically by varying the operating parameters: the contact time, membrane phase composition, and initial feed phase concentration. The mathematical models that have been used to simulate experimental data have been discussed. The scanning electron microscope combined with energy-dispersive X-ray analysis of membranes after continuous operation shows that the membrane phases are still retained within the membrane pores and only small losses of the membrane phase initially located on the surface are observed.

Highly selective and efficient transport of toluene in bulk ionic liquid membranes containing Ag + as carrier

Ionic liquids have very low vapour pressure and a very high boiling temperature and are therefore a potentially environmentally friendly solvent. In this paper, room-temperature ionic liquids are used as a bulk liquid membrane for separation of toluene from n-heptane. Aromatic hydrocarbon, toluene, is successfully transported through the ionic liquid membrane based on 1-methyl-3-octyl imidazolium chloride. Using silver ion as a carrier in 1-methyl-3-octyl imidazolium chloride membranes, batch wise extraction experiments are carried out. The separation performances, represented by the permeation rate and separation factor, are analyzed systematically by varying the operating parameters: the contact time, concentration of Ag +, stirring effect, initial feed phase concentration and temperature.

Separation of Toluene and n‐Heptane through Emulsion Liquid Membranes Containing Ag+ as Carrier

AbstractUsing silver ions as carrier in oil/water/oil‐type emulsion liquid membranes, batch wise extraction experiments were carried out to separate toluene from a mixture of toluene and n‐heptane. The separation performances, represented by the permeation rate, emulsion stability, and separation factor, were analyzed systematically by varying the operating parameters, viz., contact time, concentration of Ag+, emulsification time, surfactant concentration, membrane stabilizer concentration, relative amount of solvent, and initial feed phase concentration. The emulsion liquid membranes thus formed are stable, and Ag+ and surfactant concentrations strongly affect the permeation behavior of toluene.

Distribution of Chromium(VI) in Various Organic Solutions during Extraction and Re-extraction

Equilibrium studies on the extraction of Cr(VI) in various solvent phases have been performed. The organic solvent phase consists of Aliquat-336 (a cationic carrier) dissolved in kerosene/Shellsol TK (as an organic solvent) and hexanol (as a phase modifier). The values of the distribution coefficient for the extraction have been obtained by varying the following experimental conditions: feed solution pH (range 9−12); initial feed phase concentration (25 ppm ≤ Cr(VI) ≤ 1000 ppm); and composition of the organic phase (2 vol % ≤ Aliquat-336 ≤ 50 vol %). Re-extraction of Cr (VI) from the solvent phase was examined with an aqueous solution of HCl or NaCl by varying its pH (range 1−12) and concentration (0.5−2 mol·L-1). The values of the partition coefficient for this process are also presented. The extraction and re-extraction reaction coefficients were calculated by combining the experimental data and the kinetic expressions for the interfacial reactions. These values are presented and compared with the lite...

Extraction Equilibria of Amino Acids and Dipeptides in Various Organic Solutions

Experimental data on the partitioning of amino acids (tryptophan, phenylalanine) and dipeptides (tryptophan-leucine, phenylalanine-leucine) between the aqueous feed phase and the organic solvent phase are presented. The organic solvent phase consists ofa carrier, sodium di-2-ethylhexyl sulfosuccinate/ quaternary ammonium salt/dioleyl phosphoric acid, dissolved in (Z)-9-octadecen-1-ol (an organic solvent). The equilibrium distribution coefficient for extractions is determined by varying the following experimental conditions: feed solution pH, initial feed phase concentration, and composition of organic phase. The partition coefficient for the stripping process is also determined by varying the stripping agent (sodium hydroxide, sodium chloride, sodium carbonate), the concentration, and the pH of the stripping solution. The extraction and stripping reaction coefficients are calculated by combining the experimental data and the kinetic expressions for interfacial reactions. The variation of the values of the coefficients with the solute type (i.e. amino acid or dipeptide) and with the operating conditions of the system di-2-ethylhexyl sulfosuccinate in (Z)-9-octadecen-1-ol is presented.