scholarly journals Adsorption of lanthanides(III) from aqueous solutions by fullerene black modified with di(2-ethylhexyl)phosphoric acid

2009 ◽  
Vol 7 (1) ◽  
pp. 54-58 ◽  
Author(s):  
A. Turanov ◽  
V. Karandashevb
Keyword(s):  
Synergistic Effect ◽  
Phosphoric Acid ◽  
Aqueous Solutions ◽  
Aqueous Phase ◽  
Atomic Number ◽  
Electric Arc ◽  
Analysis Method ◽  
Sorbent Phase ◽  
Fullerene Black ◽  
Slope Analysis

AbstractFullerene black (FB) - a product of electric arc graphite vaporization after extraction of fullerenes - was modified with the di(2-ethylhexyl)phosphoric acid (D2EHPA). The distribution of D2EHPA between FB and aqueous HNO3 solutions has been studied. The effect of HNO3 concentration in the aqueous phase and that of D2EHPA concentration in the sorbent phase on the adsorption of microquantities of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y nitrates from HNO3 solutions by D2EHPA-modified FB are considered. The stoichiometry of the sorbed complexes has been determined by the slope analysis method. The efficiency of lanthanides’ adsorption increases with an increase in the element atomic number. A considerable synergistic effect has been observed upon the addition of the neutral bidentate tetraphenylmethylenediphosphine dioxide ligand to D2EHPA in the sorbent phase.

scholarly journals DETERMINATION OF TYPE OF SOLVATE OF PHOSPHORIC ACID DURING ITS EXTRACTION BY TRIBUTYL PHOSPHATE

2019 ◽  
Vol 62 (5) ◽  
pp. 104-109
Author(s):  
Nikolai F. Kizim ◽  
Anastasiya E. Tarasenkova
Keyword(s):  
Phosphoric Acid ◽  
Aqueous Solutions ◽  
Aqueous Phase ◽  
Equilibrium Constants ◽  
Material Balance ◽  
Mass Action ◽  
Acid Extraction ◽  
Processes And Reactions ◽  
Ionic Equilibria

The extraction of phosphoric acid with a solution of tri-n-butyl phosphate (TBP) in toluene from its individual aqueous solutions in a concentration range of 0-11 M is investigated. The experiments are performed at room temperature (20 ± 1 °С). The isotherms of extraction of phosphoric acid under conditions of equality of the volumes of the saturating aqueous phase and the receiving organic phase are constructed. The extraction isotherm is nonlinear, but to an acid concentration in the aqueous phase of ~ 8 M, it is close to linear, and at higher concentrations, the amount of extracted acid increases harshly. To establish the mechanism of acid extraction in the system phosphoric acid – 0.1 M solution of TBP in toluene the method of combining a laboratory and computational experiment is proposed. The optimal parameters describing the extraction of phosphoric acid from natural aqueous solutions are determined. Calculations performed in two approximations were made. In the first approximation the condition of ideality of systems is accepted. In the second approximation the deviations of the properties of phosphoric acid solutions in aqueous solution are taken into account. For the two approximations the preferential extraction of phosphoric acid molecules in the form of H3PO4 ∙ nTBP type solvates (where n = 1, 3) is shown. In the range of concentrations of phosphoric acid in the aqueous phase from 6 to 11 M, the values of equilibrium constants are estimated, which describe the processes and reactions occurring in the system: stepwise dissociation of acid, distribution of TBP, formation of solvates of phosphoric acid, distribution of the resulting solvates of acid, displacement of ionic equilibria in aqueous phase. Mathematically these processes are taken into account using the law of mass action and the equations of material balance. It is believed that the system has established an equilibrium corresponding to a given temperature and pressure. The calculated values of solvate concentrations are in satisfactory agreement with experimental data.

Sorption of Lead by the Selective Ion Exchanger Ostsorb DETA

1992 ◽  
Vol 57 (7) ◽  
pp. 1393-1404 ◽  
Author(s):  
Ladislav Svoboda ◽  
Jan Uhlíř ◽  
Zdeněk Uhlíř
Keyword(s):  
Phosphoric Acid ◽  
Aqueous Solutions ◽  
Functional Groups ◽  
Ion Exchanger ◽  
Preconcentration Procedure ◽  
Bead Cellulose

The properties of Ostsorb DETA, a selective ion exchanger based on modified bead cellulose with chemically bonded diethylenetriamine functional groups, were studied, and its applicability to the preconcentration of trace amounts of lead from aqueous solutions was verified. The conditions of the preconcentration procedure in the column and batch modes were optimized for this purpose. The results obtained were applied to the determination of lead in phosphoric acid.

Removal of naphthalene from aqueous solutions by phosphorus doped-titanium dioxide coated on silica phosphoric acid under visible light

2021 ◽  
Vol 224 ◽  
pp. 187-196
Author(s):  
Bahman Banaei ◽  
Amir Hessam Hassani ◽  
Farhang Tirgir ◽  
Abdolmajid Fadaei ◽  
Seyed Mehdi Borghaei
Keyword(s):  
Titanium Dioxide ◽  
Phosphoric Acid ◽  
Aqueous Solutions ◽  
Visible Light ◽  
Doped Titanium Dioxide ◽  
Phosphorus Doped

scholarly journals Self-generated peroxyacetic acid in phosphoric acid plus hydrogen peroxide pretreatment mediated lignocellulose deconstruction and delignification

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Dong Tian ◽  
Yiyi Chen ◽  
Fei Shen ◽  
Maoyuan Luo ◽  
Mei Huang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Acetic Acid ◽  
Synergistic Effect ◽  
Phosphoric Acid ◽  
Wheat Straw ◽  
Lignin Degradation ◽  
Acid Oxidation ◽  
Main Function ◽  
Corn Stalk ◽  
Peroxyacetic Acid

Abstract Background Peroxyacetic acid involved chemical pretreatment is effective in lignocellulose deconstruction and oxidation. However, these peroxyacetic acid are usually artificially added. Our previous work has shown that the newly developed PHP pretreatment (phosphoric acid plus hydrogen peroxide) is promising in lignocellulose biomass fractionation through an aggressive oxidation process, while the information about the synergistic effect between H3PO4 and H2O2 is quite lack, especially whether some strong oxidant intermediates is existed. In this work, we reported the PHP pretreatment system could self-generate peroxyacetic acid oxidant, which mediated the overall lignocellulose deconstruction, and hemicellulose/lignin degradation. Results The PHP pretreatment profile on wheat straw and corn stalk were investigated. The pathways/mechanisms of peroxyacetic acid mediated-PHP pretreatment were elucidated through tracing the structural changes of each component. Results showed that hemicellulose was almost completely solubilized and removed, corresponding to about 87.0% cellulose recovery with high digestibility. Rather high degrees of delignification of 83.5% and 90.0% were achieved for wheat straw and corn stalk, respectively, with the aid of peroxyacetic acid oxidation. A clearly positive correlation was found between the concentration of peroxyacetic acid and the extent of lignocellulose deconstruction. Peroxyacetic acid was mainly self-generated through H2O2 oxidation of acetic acid that was produced from hemicellulose deacetylation and lignin degradation. The self-generated peroxyacetic acid then further contributed to lignocellulose deconstruction and delignification. Conclusions The synergistic effect of H3PO4 and H2O2 in the PHP solvent system could efficiently deconstruct wheat straw and corn stalk lignocellulose through an oxidation-mediated process. The main function of H3PO4 was to deconstruct biomass recalcitrance and degrade hemicellulose through acid hydrolysis, while the function of H2O2 was to facilitate the formation of peroxyacetic acid. Peroxyacetic acid with stronger oxidation ability was generated through the reaction between H2O2 and acetic acid, which was released from xylan and lignin oxidation/degradation. This work elucidated the generation and function of peroxyacetic acid in the PHP pretreatment system, and also provide useful information to tailor peroxide-involved pretreatment routes, especially at acidic conditions. Graphical abstract

scholarly journals Removal of methylene blue from aqueous solutions using cassava peel (Manihot esculenta) modified with phosphoric acid // Remoción de azul de metileno de soluciones acuosas utilizando cáscara de yuca (Manihot esculenta) modificada con ácido fosfórico

Prospectiva ◽  
2017 ◽  
Vol 15 (2) ◽  
pp. 60-73 ◽  
Author(s):  
Alberto Ricardo Albis Arrieta ◽  
Alexandra Judith López Rangel ◽  
María Cecilia Romero Castilla
Keyword(s):  
Methylene Blue ◽  
Phosphoric Acid ◽  
Aqueous Solutions ◽  
Manihot Esculenta ◽  
Cassava Peel

Este trabajo reporta la modificación de la cáscara de la yuca con ácido fosfórico para la remoción de azul de metileno de soluciones acuosas. Se utilizó una metodología experimental con diseño compuesto central 3^2+estrella, variando la temperatura de modificación de la cáscara de yuca (113 °C a 127 °C), la relación biomasa- ácido fosfórico (1:0.5 a 1:1.5) y la concentración inicial del colorante (100 a 800 mg/L), utilizando como variables de respuesta el porcentaje de remoción y la capacidad de adsorción. Se encontró que para el porcentaje de remoción del colorante, la variable más importante es la temperatura y que la capacidad de adsorción se favorece a concentraciones altas de colorante. La cáscara de yuca modificada a la temperatura más alta (127 °C) y relación másica de biomasa- ácido 1:1 presentó mayores valores tanto para el porcentaje de remoción como para la capacidad de adsorción, los cuales fueron de 99.984% y 79.975 mg/g respectivamente. La cinética de adsorción se ajustó al modelo de pseudo segundo orden lo cual sugiere que el proceso se realiza por quimisorción, además, ajustó con las isotermas de Freundlich, lo que sugiere que la adsorción se realiza en múltiples capas.

scholarly journals Transport of Zn (II) by TDDA-Polypropylene Supported Liquid Membranes and Recovery from Waste Discharge Liquor of Galvanizing Plant of Zn (II)

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Hanif Ur Rehman ◽  
Gul Akhtar ◽  
Haroon Ur Rashid ◽  
Nauman Ali ◽  
Imtiaz Ahmad ◽  
...  
Keyword(s):  
Metal Ion ◽  
Liquid Membrane ◽  
Feed Solution ◽  
Ion Concentration ◽  
Analysis Method ◽  
Membrane Phase ◽  
Waste Discharge ◽  
Slope Analysis ◽  
Supported Liquid Membranes ◽  
Strongly Agree

The facilitated passage of Zn (II) across flat sheet supported liquid membrane saturated with TDDA (tri-n-dodecylamine) in xylene membrane phase has been investigated. The effect of acid and metal ion concentration in the feed solution, the carrier concentration in membrane phase, stripping agent concentration in stripping phase, and coions on the extraction of Zn (II) was investigated. The stoichiometry of the extracted species, that is, complex, was investigated on slope analysis method and it was found that the complex (LH)2·Zn(Cl2) is responsible for transport of Zn (II). A mathematical model was developed for transport of Zn (II), and the predicted results strongly agree with experimental ones. The mechanism of transport was determined by coupled coion transport mechanism with H+and Cl−coupled ions. The optimized SLM was effectively used for elimination of Zn (II) from waste discharge liquor of galvanizing plant of Zn (II).

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