Extraction of aniline from wastewater: equilibria, model, and fitting of apparent extraction equilibrium constants

RSC Advances ◽  
2016 ◽  
Vol 6 (8) ◽  
pp. 6125-6132 ◽  
Author(s):  
Wenshuai Chai ◽  
Xinyan Zhu ◽  
Wei Liu ◽  
Weidong Zhang ◽  
Zhiyong Zhou ◽  
...  
Keyword(s):  
Equilibrium Constants ◽  
Reactive Extraction ◽  
Equilibrium Models ◽  
Extraction Equilibrium ◽  
Extraction Complexes

Reactive extraction complexes of aniline to D2EHPA or P507 in various diluents are obtained by the fitting equilibrium models presented.

scholarly journals Equilibrium Modeling of Astaxanthin Extraction from Haematococcus pluvialis

2021 ◽  
Vol 21 (3) ◽  
pp. 554
Author(s):  
Putri Restu Dewati ◽  
Rochmadi Rochmadi ◽  
Abdul Rohman ◽  
Avido Yuliestyan ◽  
Arief Budiman
Keyword(s):  
Experimental Data ◽  
High Performance ◽  
Haematococcus Pluvialis ◽  
Equilibrium Constants ◽  
Extraction Methods ◽  
Single Step ◽  
Equilibrium Models ◽  
Extraction Equilibrium ◽  
Assisted Extraction ◽  
Solid Liquid

Astaxanthin is a natural antioxidant, and the highest content of this compound is found in Haematococcus pluvialis microalgae. Microwave-assisted extraction (MAE) is one of the environmentally friendly extraction methods and has many advantages. This study aims to investigate the extraction of astaxanthin through the MAE method using various solvents. Several equilibrium models were proposed to describe this solid-liquid equilibrium. The solid-liquid extraction equilibrium parameters were determined by minimizing the sum of squares of errors (SSE), in which equilibrium constants were needed for scaling up purposes. Previously, the microalgae were pretreated with HCl to soften their cell walls in order to improve the extraction recovery. In this study, dichloromethane, acetone, methanol, and ethanol were used as the solvents for extraction. The astaxanthin concentration was determined by high-performance liquid chromatography (HPLC) and spectrophotometry. Astaxanthin was found to attain equilibrium at 57.42% recovery in a single-step extraction. Thus, several steps were required in sequence to obtain an optimum recovery. The experimental data were fitted to three equilibrium models, namely, Henry, Freundlich, and Langmuir models. The experimental data were well fitted to all the models for the extraction in dichloromethane, methanol, ethanol and acetone, as evident from the almost same SSE value for each model.

scholarly journals Comparative Extraction of Aluminum Group Metals Using Acetic Acid Derivatives with Three Different-Sized Frameworks for Coordination

Separations ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 211
Author(s):  
Keisuke Ohto ◽  
Nako Fuchiwaki ◽  
Hiroaki Furugou ◽  
Shintaro Morisada ◽  
Hidetaka Kawakita ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Metal Ions ◽  
Spectroscopic Data ◽  
Equilibrium Constants ◽  
Structural Effects ◽  
Extraction Equilibrium ◽  
Ph Values ◽  
Slope Analysis ◽  
Coordination Sites ◽  
Extraction Properties

We prepared acetic acid derivatives using three different frameworks, calix[4]arene, alkenyltrimethylol, and trihydroxytriphenylmethane, which differ in the number and size of their coordination sites. We further investigated the extraction properties for aluminum group metal ions. All three extraction reagents exhibited increased extraction compared with the corresponding monomeric compounds, owing to structural effects. The extraction reaction and extraction equilibrium constants were determined using a slope analysis. Their extraction abilities, separation efficiencies, and potential coordination modes are discussed using the extraction equilibrium constants, half-pH values, and spectroscopic data. The calix[4]arene and trihydroxytriphenylmethane derivatives demonstrated allosteric co-extraction of indium ions (In3+) with an unexpected stoichiometry of 1:2.

scholarly journals Solvent extraction of Sc(III) from sulfuric acid solution by bis(2-ethylhexyl) phosphonic acid in toluene

2002 ◽  
Vol 67 (4) ◽  
pp. 265-272 ◽  
Author(s):  
Devendra Koladkar ◽  
Purshottam Dhadke
Keyword(s):  
Sulfuric Acid ◽  
Acid Solution ◽  
Sulfuric Acid Solution ◽  
Equilibrium Constants ◽  
Phosphinic Acid ◽  
Extraction Equilibrium ◽  
H2so4 Concentration ◽  
Liquid Liquid Extraction ◽  
Extraction Reaction ◽  
Reaction Proceeds

Liquid-liquid extraction of scandium(III) from sulfuric acid solution using bis(2-ethylhexyl) phosphinic acid (PIA-8) in toluene has been studied. The extraction of scandium(III) was found to be quantitative with 0.03 M PIA-8 in toluene in the acidic range of 0.1?0.5 M and 6.0?8.0 M H2SO4. The effect of the reagent concentration and other parameters on the extraction of scandium(III) was also studied. The stoichiometry of the extracted species of scandium(III) was determined on the basis of the slope analysis method. The extraction reaction proceeds via the cation exchange mechanism in the H2SO4 concentration range of 0.1?0.5M and the extracted species is ScR3.3HR. However, at higher acidity (6.0M?8.0M H2SO4) it proceeds by solvation. The extracted species is HSc(SO4)2.4HR. The temperature dependencies of the extraction equilibrium constants were examined to estimate the apparent thermodynamic functions (?H, ?S and ?G) for the extraction reaction.

scholarly journals Equilibrium Study on Reactive Extraction of Lactic Acid with Tri-n – Butyl Phosphate in n - Hexane

2013 ◽  
Vol 12 (2) ◽  
pp. 1
Author(s):  
Panut Mulyono ◽  
Anita Pardah
Keyword(s):  
Aqueous Solution ◽  
Lactic Acid ◽  
Ambient Temperature ◽  
Carboxylic Acids ◽  
Distribution Ratio ◽  
Equilibrium Constants ◽  
Reactive Extraction ◽  
Extraction Temperature ◽  
Process Selection ◽  
Initial Concentration

Extraction of carboxylic acids from dilute aqueous solution using traditional solvents such as ketones, alcohols, ethers, and ester is inefficient because the distribution ratio is rather low. Reactive extraction which exploits reversible chemical complexation is an effective separation process for extraction of carboxylic acids from aqueous streams such as fermentation broths and wastewaters. In the extraction process, selection of the solvent is an important aspect to be considered. Considering its solubility in water, cost and availability, tri-n-butyl phosphate (TBP) seems to be an attractive solvent for the extraction of lactic acid from aqueous solution. The purpose of this experiment is to study the equilibrium of the reactive extraction of lactic acid in aqueous solution with TBP in n-hexane. The parameters studied in this experiment were initial concentration of lactic acid in the aqueous phase, TBP concentration in n-hexane phase, and the extraction temperature. The experiments at ambient temperature were carried out using a separatory funnel, while the experiments at other than ambient temperature were carried out using erlenmeyer flask and water bath shaker to adjust the temperature. In this experiment, the initial concentration of lactic acid was varied from 0.1 to 0.5 gmol/dm3. The range of initial TBP concentrations in n-hexane was 0.1 to 1.0 gmol/dm3 and the extraction temperature range was 283 to 313 K. The experimental results showed that the higher the initial concentration of lactic acid in aqueous solution, the higher the distribution ratio for a fixed TBP concentration and extraction temperature. For a fixed initial concentration of lactic acid in aqueous solution and extraction temperature, the distribution ratio of lactic acid is increased by increasing TBP concentration. The overall equilibrium constants (Kpq) for the experiments using TBP concentration ranging from 0.1 to 1.0 gmol/dm3 at the extraction temperature of 293 K are calculated to be 0.0668 to 0.5144. Kpq for the experiments at the temperature ranging from 283 to 313 K at the initial concentration of lactic acid of 0.2 gmol/L are found to be 0.0122 to 0.8856. The Kpq as a function of temperature (T) in K can be expressed as ln Kpq = 10,596/T - 38.08 with sum of square of error of 0.14.

Novel Route for Recovery of Glycerol from Aqueous Solutions by Reversible Reactions

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Vijaya lakshmi Ch ◽  
Udaybhaskar Ravuru ◽  
Viswanath Kotra ◽  
Satyavathi Bankupalli ◽  
Prasad R.B.N.
Keyword(s):  
Aqueous Solutions ◽  
Extraction Efficiency ◽  
Equilibrium Constants ◽  
Complete Recovery ◽  
Reactive Extraction ◽  
Maximum Efficiency ◽  
Reported Study ◽  
Acetalization Reaction ◽  
Hydrolysis Of ◽  
Acetone System

Glycerol in aqueous solutions was reacted with acetaldehyde and acetone to form glycerol acetals. The formed acetal was extracted using a solvent and the glycerol is recovered by hydrolysis of the extractant. The reaction equilibrium constants ranged from 1-35 for glycerol-acetaldehyde system and 2.2-5.5 for glycerol-acetone system, respectively. Phase equilibrium measurements showed that the distribution coefficient was from 1.5-8.5 for glycerol-acetaldehyde system and 2-6.5 for glycerol-acetone system. The extraction efficiency of the solvent increased with increase in temperature. Maximum efficiency achieved was 94% at the refluxing temperature of toluene. The reactive extraction route to obtain glycerol is more economical than the distillation route in pure form. The maximum conversion obtained during the acetalization reaction was 87% and the extraction efficiency achieved was 94%. The hydrolysis of the acetal recorded complete recovery of high purity glycerol. The reported study has an application for the recovery of pure glycerol from aqueous solutions generated during biodiesel processing.

scholarly journals New Trident Molecule with Phosphoric Acid Functionality for Trivalent Rare Earth Extraction

2017 ◽  
Vol 17 (3) ◽  
pp. 491 ◽  
Author(s):  
Keisuke Ohto ◽  
Hiromasa Murashima ◽  
Hiroshi Murakami ◽  
Shintaro Morisada ◽  
Hidetaka Kawakita ◽  
...  
Keyword(s):  
Rare Earth ◽  
Phosphoric Acid ◽  
Rare Earths ◽  
Equilibrium Constants ◽  
Extraction Equilibrium ◽  
Ph Values ◽  
Extraction Behavior ◽  
Separation Factors ◽  
Trivalent Rare Earth ◽  
Rare Earth Extraction

Tripodal extraction reagent with three phosphoric acid groups, together with the corresponding monopodal molecule has been prepared to investigate some metals extraction behavior, in particular, trivalent rare earth elements (REEs). The tripodal reagent exhibited extremely high selectivity for metals with high valency such as Zr(IV), In(III), Lu(III), and Fe(III). Tripodal reagent also exhibited exceptionally high extraction ability compared with the corresponding monopodal one in the extraction of trivalent rare earths. The result for the stoichiometry of tripodal reagent to heavy rare earths showed the inflection point between Er (2:1 for a ligand with ion) and Tm (1:1). The extraction reactions were determined for all rare earths with both reagents. The extraction equilibrium constants (Kex), the separation factors (β), half pH values (pH1/2), difference half pH values (ΔpH1/2) for extraction of REEs with both reagents are estimated.

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