scholarly journals Sorption performances of TiO(OH)(H2PO4)·H2O in synthetic and mine waters

RSC Advances ◽  
2017 ◽  
Vol 7 (4) ◽  
pp. 1989-2001 ◽  
Author(s):  
Mylène Trublet ◽  
Marina V. Maslova ◽  
Daniela Rusanova ◽  
Oleg N. Antzutkin
Keyword(s):  
Exchange Capacity ◽  
Titanium Phosphate ◽  
Mine Waters ◽  
Sorption Behaviour ◽  
Fast Kinetics ◽  
First Report

The first report on sorption behaviour of a titanium phosphate sorbent containing entirely –H2PO4 groups reveals a high exchange capacity and fast kinetics.

Sorption of Eu(III) on Fe–montmorillonite relevant to geological disposal of HLW

2018 ◽  
Vol 106 (12) ◽  
pp. 971-983 ◽  
Author(s):  
Santosh Chikkamath ◽  
Madhuri A. Patel ◽  
Aishwarya S. Kar ◽  
Vaibhavi Raut ◽  
Bhupendra Singh Tomar ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Cation Exchange ◽  
Exchange Capacity ◽  
High Level Waste ◽  
Sudden Increase ◽  
Exchange Method ◽  
Sorption Data ◽  
Sorption Behaviour ◽  
Geological Disposal ◽  
Buffer Material

Abstract Montmorillonite (Mt) is the major clay mineral of bentonite, which is the candidate buffer material in the engineered barrier system for geological disposal of high level waste (HLW). The alteration of Mt due to its interaction with carbon steel (overpack) can produce Fe–Mt. In order to understand the basic properties of Fe–Mt, the sorption studies using Eu(III) are reported here. For this, Fe(III)–Mt was prepared by conventional cation exchange method using FeCl3 with Na–Mt. The obtained Fe(III)–Mt was then reduced to Fe(II)–Mt using ascorbic acid. Both the samples were characterized based on their X-ray diffraction, Fourier transform infrared spectra, cation exchange capacity and specific surface area. The batch sorption studies of Eu(III) were conducted for both Fe(III)–Mt and Fe(II)–Mt as a function of pH (3–10), ionic strength (0.001 M–1 M) and Eu(III) concentration (10−8–10−3 M). The distribution coefficient (Kd) was found to be higher for Fe(III)–Mt compared to Fe(II)–Mt and Na–Mt. The sudden increase in sorption in the pH range 4.5–6 and remaining constant beyond it indicates ion exchange mechanism at pH<4.5, with surface complexation mechanism dominating the sorption at pH>4.5. This is further corroborated by ionic strength dependent sorption data which shows decrease in sorption capacity of Fe–Mt with increasing ionic strength at low pH, but remaining more or less unchanged at higher pH. Eu(III) adsorption isotherm on Fe–Mt increased linearly with [Eu(III)] reaching saturation at 10−5 M and 10−4 M for Fe(III)–Mt and Fe(II)–Mt, respectively. The amount of iron released from Fe–Mt and Fe(II)/Fetotal during sorption were estimated to understand the effect on Eu(III) sorption behaviour by release of interlayer iron in Fe–Mt.

Sorption-desorption behaviour of caesium in some Western Australian soils

Soil Research ◽  
1990 ◽  
Vol 28 (6) ◽  
pp. 929 ◽  
Author(s):  
B Singh ◽  
RJ Gilkes
Keyword(s):  
Soil Erosion ◽  
Clay Mineralogy ◽  
Sandy Soils ◽  
Exchange Capacity ◽  
Erosion And Deposition ◽  
Sorption Behaviour ◽  
137Cs Technique ◽  
Nuclear Tests ◽  
Western Australian ◽  
Different Soils

Soil caesium-137 derived from past atmospheric nuclear tests is increasingly being used as an indicator of soil erosion and deposition on the basis that fallout 137Cs has been retained by soils, although this assumption has not been thoroughly tested for different soils. The sorption behaviour of some Western Australian soils indicates that Cs is differentially sorbed as a consequence of differences in clay mineralogy. Kaolinitic sandy soils of low exchange capacity sorb Cs in preference to Ca and Na, with the specificity for Cs being higher at lower concentrations of Cs in solution. lllitic and smectitic soils sorbed more Cs than kaolinitic soils and retained more than 50% of sorbed Cs after a series of extractions with salt solutions. Retention by kaolinitic soils was less but, for the concentrations of Cs likely to occur in soils, it seems that most Cs is retained so that it is probable that the 137Cs technique can be used with confidence for the measurement of soil erosion and deposition for many Western Australian soils.

Relations between sorption behavior and electrokinetic remediation effect in soils contaminated with heavy metals

Soil Research ◽  
2008 ◽  
Vol 46 (5) ◽  
pp. 485 ◽  
Author(s):  
Zhemin Shen ◽  
Bingxin Ju ◽  
Xuejun Chen ◽  
Wen-hua Wang
Keyword(s):  
Exchange Capacity ◽  
Metal Mobility ◽  
Purple Soil ◽  
Sorption Behavior ◽  
Sorption Behaviour ◽  
Fast Reactions ◽  
Exchange Processes ◽  
Heavy Metal Sorption ◽  
Remediation Efficiency ◽  
Adsorption Desorption

Adsorption–desorption is an important mechanism for controlling metal mobility in soil and has a large effect on remediation efficiency. Very little research has examined the relations between heavy metal sorption behaviour and electrokinetic (EK) remediation effect. Four typical soil samples in China (Chernozem, Fluvisol, Yellow brown earth, and Purple soil) were studied. Adsorption isotherms were fit to Freundlich equations. EK removal ratios in the 4 soils were: Purple soil > Yellow brown earth > Fluvisol > Chernozem. Results show that the influencing characteristics significant to Cd EK removal order as follows: total organic carbon (TOC) > 1/n (Freundlich constant) > clay ratio > K (Freundlich constant) > cation exchange capacity > background pH. When 1/n (Freundlich constant) increases by 0.124 or TOC increases by 0.858 g/kg in soils, EK removal ratio (%) of Cd decreases by 1.0%. A ‘2-reactions’ mechanism during EK remediation is speculated, including rapid and slow reactions. Fast reactions are attributed to H+–M2+ exchange processes occurring on the surfaces of different inorganic phases and to the dissolution of the water-insoluble precipitates. Slow irreversible reactions refer to H+ ions exchanging with metal ions bound in the internal lattice sites and organic matter being oxidised by oxidants produced by electrochemical reactions. Slow reactions limit the EK remediation effect.

scholarly journals Chromatographic Utilization of the Sorption Behaviour of Some Nitrophenols on Acid-Treated Alumina

1992 ◽  
Vol 9 (2) ◽  
pp. 92-108
Author(s):  
Sangeeta Jha ◽  
G.L. Mundhara ◽  
R.M. Sharma ◽  
J.S. Tiwari
Keyword(s):  
Picric Acid ◽  
Distribution Coefficients ◽  
Exchange Capacity ◽  
Electron Interaction ◽  
Chemical Pretreatment ◽  
Ion Content ◽  
Experimental Conditions ◽  
Ion Exchange Capacity ◽  
Sorption Behaviour ◽  
Weak Chemical

Alumina for adsorption chromatography has been subjected to chemical pretreatment with HNO3 and CH3COOH of various concentrations and samples of surface-phase pH 1.5–9.0 [Al2O3(n)] and 3.0–9.0 [Al2O3(a)] prepared. The surface area, NO−3 and CH3COO− ion content and OH− ion-exchange capacity of the samples were determined. Sorption/desorption studies of the nitrophenols, 2,4-dinitrophenol (DNP) and 2,4,6-trinitrophenol (picric acid, PA), from aqueous solution under a variety of experimental conditions, were carried out on the substrates. Sorption was found to depend on the pH of the substrate and the acid used for pretreatment. Mximum sorption was observed at pH 6.0 [Al2O3(n)] and pH 5.0 [Al2O3(a)]. The process was fast (10 min to 24 h) and exothermic (30–60°C), with low values for the isosteric heats of adsorption (−7 to −64 kJ/mol). The desorption efficiency and retarding influence of the anions on adsorption was in the order: PO3–4 > C2O2–4 > SO2–4 > CH3COO− > NO−3 Acid treatment, and hence the anion present (NO−3 or CH3COO−), appears to modify the sorption properties of alumina significantly. Anion-exchange sorption and weak chemical interactions (hydrogen bonding and π-electron interaction) appear to control the sorption of the solutes on pretreated alumina. The distribution coefficients for adsorption and desorption have been determined, and on the basis of these data the elution behaviour and column chromatography of the system examined.

Sorption of Some Fission Products and Actinides in Concrete Systems

1985 ◽  
Vol 50 ◽  
Author(s):  
S. Höglund ◽  
L. Eliasson ◽  
B. Allard ◽  
K. Andersson ◽  
B. Torstenfelt
Keyword(s):  
Pore Water ◽  
Fission Products ◽  
Exchange Capacity ◽  
Matrix Composition ◽  
Cement Matrix ◽  
Pore Waters ◽  
High Concentration ◽  
Hydro Power ◽  
Sorption Behaviour ◽  
Competing Cations

AbstractThe sorption of some actinides (Th, U, Np, Pu and Am) and fission products (I, Cs) was measured on two types of Standard Portland cements as well as on samples from old (70 years) hydro power dam constructions using a batch technique. Pore water compositions were analysed, and artificial pore water solutions were used as aqueous phases in the experiments. Measurements were also performed on five other concrete types (not reported in detail in this paper) to illustrate the effects of the cement matrix composition on the sorption behaviour of the radionuclides.The sorption of actinides in the trivalent (americium), tetravalent (thorium) pentavalent (neptunium) and hexavalent (uranium) states was high in all the studied concrete systems.Generally, the sorption of cesium was low due to the low exchange capacity of the cement and the high concentration of competing cations in the pore waters.The sorption of iodine was much higher than in most silicate minerals of geologic origin.The differences between the various concrete systems were generally minor in terms of their sorbing capacities.

scholarly journals Modeling of Ion Exchange Processes to Optimize Metal Removal from Complex Mine Water Matrices

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3109
Author(s):  
Angela Isabel Pedregal Montes ◽  
Janith Abeywickrama ◽  
Nils Hoth ◽  
Marlies Grimmer ◽  
Carsten Drebenstedt
Keyword(s):  
Ion Exchange ◽  
Mine Water ◽  
Reactive Transport ◽  
Metal Removal ◽  
Transport Model ◽  
Breakthrough Curves ◽  
Exchange Capacity ◽  
Operating Conditions ◽  
Mine Waters ◽  
Exchange Processes

The modeling of ion exchange processes could significantly enhance their applicability in mine water treatment, as the modern synthetic resins give unique advantages for the removal of metals. Accurate modeling improves the predictability of the process, minimizing the time and costs involved in laboratory column testing. However, to date, the development and boundary conditions of such ion exchange systems with complex mine waters are rarely studied and poorly understood. A representative ion exchange model requires the definition of accurate parameters and coefficients. Therefore, theoretical coefficients estimated from natural exchange materials that are available in geochemical databases often need to be modified. A 1D reactive transport model was developed based on PhreeqC code, using three case scenarios of synthetic mine waters and varying the operating conditions. The first approach was defined with default exchange coefficients from the phreeqc.dat database to identify and study the main parameters and coefficients that govern the model: cation exchange capacity, exchange coefficients, and activity coefficients. Then, these values were adjusted through iterative calibration until a good approximation between experimental and simulation breakthrough curves was achieved. This study proposes a suitable methodology and challenges for modeling the removal of metals from complex mine waters using synthetic ion exchange resins.

scholarly journals Comparison of The Sorption Kinetics of Lead(II) and Zinc(II) on Titanium Phosphate Ion-Exchanger

2020 ◽  
Vol 21 (2) ◽  
pp. 447 ◽  
Author(s):  
Marina V. Maslova ◽  
Vladimir I. Ivanenko ◽  
Nataliya Yu. Yanicheva ◽  
Natalia V. Mudruk
Keyword(s):  
Low Cost ◽  
Effective Diffusion ◽  
Kinetic Studies ◽  
Zinc Ion ◽  
Sorption Kinetics ◽  
Titanium Phosphate ◽  
Industrial Wastes ◽  
High Concentration ◽  
Fast Kinetics ◽  
Lead And Zinc

The treatment of heavy metal-contaminated wastewater is an important action to reduce The negative impacts of industrial wastes on water bodies. This work focuses on The application of a low-cost titanium (IV) phosphate sorbent of TiO(OH)H2PO42H2O chemical composition toward lead and zinc ions depending on their concentration and The temperature of The solution. The kinetic studies showed that The values of The rate of intraparticle diffusion and The effective diffusion coefficients for Zn2+ were considerably higher than those for Pb2+. To explain The difference between The sorption kinetics rates for Pb2+ and Zn2+, The effective radius and dehydration degree of The adsorbed ions were calculated. The sorbent capability of The lead and zinc ion removal and its excellent efficiency in The presence of a high concentration of calcium ions were demonstrated using simulated mine water. Due to The fast kinetics and The high exchange capacity of titanium phosphate toward divalent ions, this sorbent can be considered as a promising material for The concentration and immobilization of heavy metals into The phosphate matrix.

Synthesis, Characterization and Thermodynamics of Exchange Using Zirconium Titanium Phosphate Cation Exchanger

2007 ◽  
Vol 72 (9) ◽  
pp. 1306-1318 ◽  
Author(s):  
Rakesh P. Thakkar ◽  
Uma V. Chudasama
Keyword(s):  
Ion Exchange ◽  
Sol Gel ◽  
Entropy Change ◽  
Exchange Capacity ◽  
Titanium Phosphate ◽  
X Ray Diffraction ◽  
Ion Exchange Capacity ◽  
Standard Gibbs Energy Change ◽  
Equilibrium Exchange ◽  
Zirconium Titanium Phosphate

A mixed material of the class of tetravalent bimetallic acid (TBMA) salt - zirconium titanium phosphate (ZTP) - has been synthesized by the sol-gel technique. ZTP has been characterized by elemental analysis, thermal analysis (TGA, DTA), FTIR, X-ray diffraction and SEM. Ion exchange capacity (IEC) of the material has been determined and the effect of calcination (373-773 K) on IEC studied and chemical stability of the material in various media (acids, bases and organic solvents) assessed. Further, the equilibrium exchange of H in ZTP for Mg2+, Ca2+, Sr2+ and Ba2+ ions has been studied at 303, 313, 323 and 333 K at constant ionic strength. On the basis of the exchange isotherms, various thermodynamic parameters such as equilibrium constant (K), standard gibbs energy change (∆Go), entropy change (∆So) and enthalpy change (∆Ho) have been calculated. The parameters were correlated with the ion exchange characteristics of the material.

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