Removal of textile dye mixtures by using modified Mg-Al-Cl layered double hydroxide (LDH)

The removal of Indigo Carmin (IC) and Congo Red (CR) dye mixtures using layered double hydroxide (LDH) (modified with sodium dodecyl sulfate (SDS)) has been studied. In the experimental context of this study, LDH was synthesized under a nitrogen atmosphere at room temperature using the coprecipitation method and characterized by Fourier transform infrared specroscopy (FTIR), X-ray diffraction (XRD), energy dispersive analysis of X-rays (EDAX) and scanning electron microscopy (SEM) analyses. Contact time, temperature, and initial dye concentration on the adsorption process have been investigated. Results show that the maximum removal of IC and CR was obtained as about 50% and 95%, respectively. The isothermal data were fitted to Langmuir, Freundlich, and Temkin adsorption isotherms. Elovich and other kinetic model equations were applied. Adsorption depended on the starting naphthalene concentration at investigated various temperatures (298, 308, and 318K) significantly

Extraction Equilibria of Acrylic Acid from Aqueous Solutions by Amberlite LA-2 in Various Diluents

Amberlite LA-2 (a secondary amine mixture) has been studied for its ability to extract acrylic acid at different amine concentrations. The extraction of acrylic acid by Amber lite LA-2 dissolved in seven single solvents (cyclohexane, 2-octanone, toluene, methyl isobutyl ketone (MIBK), iso-octane, hexane, and 1-octanol) has been investigated with respect to different amine concentrations at 298.15 K. In the extraction, two acid amine complexes, (HO):(R2N) and (HO):(R2N)(2), have been assumed to exist in the organic phase in the case of proton-donating diluents, while the complexes (HO):(R2N) and (HO)(2):(R2N)(3) have been suggested in the case of nonproton-donating diluents. Important data for the design and analysis of different separation processes have been obtained as a result of batch experiments. These important data are distribution coefficients (D), loading factors (Z), extraction efficiency (E), and overall extraction constants (K-11, K-12, K-23). The maximum removal of acrylic acid is 98.22 % To with MIBK at 0.93 mol.L-1 initial concentration of Amber lite LA-2

Extraction of Glycolic Acid from Aqueous Solutions by Amberlite LA-2 in Different Diluent Solvents

In this work, extraction of glycolic acid was investigated from aqueous solutions by different organic solutions containing Amberlite LA-2, a secondary amine mixture. The extraction of glycolic acid with Amberlite LA-2 dissolved in six individiual solvents has been measured at 298.15 K. The solvents used were I-octanol, cyclohexane, isooctane, toluene, 2-octanone, and methyl isobutyl ketone (MIBK). The effect of different parameters on recovery of glycolic acid has been investigated. The investigated parameters were selected as solvent type, amine concentration, and initial acid concentration. To show the effect of these parameters, distribution coefficients (D), loading factors (Z), and extraction efficiency (E) are calculated. The maximum removal of glycolic acid is 79.43% with MIBK and 0.93 mol.L(-1) initial concentration of Arnberlite LA-2

(Liquid plus liquid) equilibria of the (water plus carboxylic acid plus dibasic esters mixture (DBE-2)) ternary systems

(Liquid + liquid) equilibrium (LLE) data for the {water + carboxylic acid + dibasic esters mixture (dimethyl adipate + dimethyl glutarate)} system were determined experimentally at T= 298.2 K for each acid. In this work, we studied formic acid, acetic acid and propionic acid. All the phase diagrams were obtained by determining solubility curve and tie-line data. The reliability of the experimental tie-line data was confirmed by using the Othmer-Tobias correlation. The UNIFAC and modified UNIFAC models were used to predict the phase equilibrium in the system determined from experimental data using the interaction parameters between CH2, CH3, HCOOH, COOH, CH3COO, and H2O functional groups. Distribution coefficients and separation factors were evaluated for the immiscibility region. (C) 2014 Elsevier B.V. All rights reserved

Development of New Hydrophobic Deep Eutectic Solvents Based on Trioctylphosphine Oxide for Reactive Extraction of Carboxylic Acids

Separation of carboxylic acids from their aqueous solutions by reactive extraction using a newly developed deep eutectic solvent (DES) was investigated. DESs were prepared using trioctylphosphine oxide (TOPO, T) and menthol (M) binary mixtures prepared in different mole ratios. H-1 NMR (nuclear magnetic resonance spectroscopy), P-31 NMR, and differential scanning calorimetry (DSC) analyses were performed to characterize the solvents that were obtained. The physical properties of the DES formed were determined by measuring density, viscosity, and refractive index values. Extraction was carried out using the DESs with organic acids (formic, acetic, propionic, glycolic, lactic, malic, and citric acid) containing different numbers of hydroxyl and carboxyl groups. Extraction efficiency (E %) and distribution coefficient (D) values were calculated to evaluate the obtained results. Response surface methodology was used to investigate the effects of the experimental conditions on reactive extraction yield and to obtain model equations of the acids

A novel approach for itaconic acid extraction: Mixture of trioctylamine and tridodecylamine in different diluents

Extraction of itaconic acid has been investigated from aqueous solutions by six kind of different solutions of trioctylamine (TOA)-tridodecylamine (TDA) mixtures. Solvents have selected as dimethyl phthalate (DMP), methyl isobutyl ketone (MIBK), 2-octanone, 1-octanol, cyclohexyleacetate (CHA), and 1-decanol. Distribution and equilibrium data for design of separation equipments have been obtained as a result of batch extraction of itaconic acid. It has been calculated that distribution coefficients (D), loading factors (Z), extraction efficiency (E). The maximum removal of itaconic acid has been obtained as 98.39% with DMP and 3.14 mol L-1 initial concentration of TOA-TDA mixture. (C) 2012 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved

Extraction equilibria of propionic acid from aqueous solutions by Amberlite LA-2 in diluent solvents

Amberlite LA-2 (a secondary amine) was studied for its ability to extract propionic acid at different amine concentrations. The extraction of propionic acid by Amberlite LA-2 dissolved in seven single solvents (cyclohexane, 2-octanone, toluene, methyl isobutyl ketone, isooctane, haxane and 1-octanol) was investigated under various amine concentrations at 298.15 K. Using Bizek's approach, two acids: amine complexes, (HO):(R2N) and (HO):(R2N)(2), are assumed to exist in the organic phase in case of proton-donating diluents, while the complexes (HO):(R2N) and (HO)(2):(R2N)(3) are suggested in the case of non-proton-donating diluents. Important data for design of separation units have been obtained as a result of batch experiments. These data are distribution coefficients (D), loading factors (Z), extraction efficiency (E) and overall extraction constants (K-11, K-12, K-23). The maximum removal of glycolic acid is 94.68% with MIBK and 0.93 mol L-1 initial concentration of Amberlite LA-2. (C) 2009 Elsevier B.V. All rights reserved

Extraction Equilibria of Succinic Acid from Aqueous Solutions by Amberlite LA-2 in Various Diluents

The aim of this study is to investigate the extraction of succinic acid from aqueous solutions by different organic solutions containing Amberlite LA-2, a secondary amine mixture. Extraction equilibria of succinic acid in the solution of Amberlite LA-2 in seven individual diluents at a temperature of 298.15 K have been measured. Using Bizek's approach, two acid-amine complexes, (HO)center dot(R2N) and (HO)center dot(R2N)(2), are assumed to exist in the organic phase in the case of proton-donating diluents, while the complexes (HO)center dot(R2N) and (HO)(2)center dot(R2N)(3) are suggested in the case of nonproton-donating diluents. Important data for the design of separation units have been obtained as a result of batch experiments. These data are distribution coefficients (D), loading factors (Z), extraction efficiencies (E), and overall extraction constants (K-11, K-12, and K-23)

Removal of Some Carboxylic Acids from Aqueous Solutions by Hydrogels

Carboxylic acids are biotechnological substances that are used extensively in many industries, thus production and separation of carboxylic acids from product mixtures are important scientific and economic problems. The aim of this work was to investigate the removal of acetic, citric, lactic, and tartaric acids from aqueous solutions. With this aim, first the effects of time, temperature, and mixing on separation of the carboxylic acids from aqueous solutions were investigated by experimental work. After the experimental conditions were determined, separation was undertaken for different initial acid concentrations at constant hydrogel concentration. The effect of different gel-acid mass ratios on adsorption at constant initial acid concentrations was determined. The removal of acetic acid was 59.74 %, of lactic acid was 55.45 %, of citric acid was 54.22 %, and of tartaric acid was 56.85 % with a 1.5 hydrogel/acid mass ratio at the lowest concentration of each acid. Results obtained from the experimental work have been used with the Freundlich isotherm

Multiwall Carbon Nanotube for Adsorption of Acetic Acid

The adsorption capabilities of multiwall carbon nanotubes (MWCNTs) for acetic acid have been investigated experimentally and theoretically. Carbon nanotubes (CNTs) are an important new material in the carbon family. Adsorption time required to attain the steady state and influences of quantities of alumina, effects of temperature, and effects of initial values of acetic acid concentrations have been determined experimentally. The most common used adsorption isotherms have been drawn by using experimental results. These are selected as Langmuir, Freundlich, and Temkin. In experimental works, the equilibrium is considerably affected by initial concentration values of acetic acid at various temperatures (278 K, 298 K, 318 K). Langmuir isotherm has been found the best suitable for acetic acid. Also kinetic models for adsorption such as Elovich and pseudo-first and second orders have been used. The equilibrium results fit well within the Elovich model and while the pseudo-second order model is a good representation of the adsorption, the pseudo-first order approach does not fit with experimental data. The model parameters have been calculated