Effect of Ionic Strength, Temperature on Equilibrium and Kinetics of Arsenic Adsorption using Magnetite

2014 ◽  
Vol 40 (2) ◽  
pp. 90-97 ◽  
Author(s):  
Kaoru Ohe ◽  
Tatsuya Oshima ◽  
Yoshinari Baba
Keyword(s):  
Ionic Strength ◽  
Arsenic Adsorption ◽  
Equilibrium And Kinetics ◽  
Kinetics Of

Study of the Cu(II) removal from aqueous solutions by adsorption on titania

2013 ◽  
Vol 12 (3) ◽  
pp. 239-247
Keyword(s):  
Heavy Metals ◽  
Ionic Strength ◽  
Toxic Metals ◽  
Low Cost ◽  
Lateral Interaction ◽  
Tio2 Surface ◽  
High Toxicity ◽  
Removal Of Heavy Metals ◽  
Solution Parameters ◽  
Kinetics Of

The removal of heavy metals from wastewaters is a matter of paramount importance due to the fact that their high toxicity causes major environmental pollution problems. One of the most efficient, applicable and low cost methods for the removal of toxic metals from aqueous solutions is that of their adsorption on an inorganic adsorbent. In order to achieve high efficiency, it is important to understand the influence of the solution parameters on the extent of the adsorption, as well as the kinetics of the adsorption. In the present work, the adsorption of Cu(II) species onto TiO2 surface was studied. It was found that the adsorption is a rapid process and it is not affected by the value of ionic strength. In addition, it was found that by increasing the pH, the adsorbed amount of Cu2+ ions and the value of the adsorption constant increase, whereas the value of the lateral interaction energy decreases.

Adsorption Equilibrium and Kinetics of CO2 and H2O on Activated Carbon

2012 ◽  
Vol 27 (2) ◽  
pp. 139-145 ◽  
Author(s):  
Dong XU ◽  
Jun ZHANG ◽  
Gang LI ◽  
Penny XIAO ◽  
Paul WEBLEY ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Adsorption Equilibrium ◽  
Equilibrium And Kinetics ◽  
Adsorption Equilibrium And Kinetics ◽  
Kinetics Of

Kinetics of hydrolysis of peroxodisulphate ions in acidic medium to peroxomonosulphuric acid

1981 ◽  
Vol 46 (5) ◽  
pp. 1229-1236 ◽  
Author(s):  
Jan Balej ◽  
Milada Thumová
Keyword(s):  
Ionic Strength ◽  
Rate Constants ◽  
Acidic Medium ◽  
Measured Data ◽  
Molar Ratios ◽  
Starting Solution ◽  
Kinetics Of Hydrolysis ◽  
Rate Of Hydrolysis ◽  
Kinetics Of ◽  
Hydrolysis Of

The rate of hydrolysis of S2O82- ions in acidic medium to peroxomonosulphuric acid was measured at 20 and 30 °C. The composition of the starting solution corresponded to the anolyte flowing out from an electrolyser for production of this acid or its ammonium salt at various degrees of conversion and starting molar ratios of sulphuric acid to ammonium sulphate. The measured data served to calculate the rate constants at both temperatures on the basis of the earlier proposed mechanism of the hydrolysis, and their dependence on the ionic strength was studied.

Kinetics and Mechanism of Hexachloroiridate(IV) Oxidation of Arsenic(III) in Acidic Perchlorate Solutions

1992 ◽  
Vol 57 (7) ◽  
pp. 1451-1458 ◽  
Author(s):  
Refat M. Hassan
Keyword(s):  
Ionic Strength ◽  
Fractional Order ◽  
Activation Parameters ◽  
Order Reaction ◽  
First Order Reaction ◽  
Intermediate Complex ◽  
Constant Ionic Strength ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Kinetics Of

The kinetics of oxidation of arsenic(III) by hexachloroiridate(IV) at lower acid concentrations and at constant ionic strength of 1.0 mol dm-3 have been investigated spectrophotometrically. A first-order reaction in [IrCl62-] and fractional order with respect to arsenic(III) have been observed. A kinetic evidence for the formation of an intermediate complex between the hydrolyzed arsenic(III) species and the oxidant was presented. The results showed that decreasing the [H+] is accompanied by an appreciable acceleration of the rate of oxidation. The activation parameters have been evaluated and a mechanism consistent with the kinetic results was suggested.

scholarly journals Silica Removal from a Paper Mill Effluent by Adsorption on Pseudoboehmite and γ-Al2O3

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2031
Author(s):  
Ruben Miranda ◽  
Isabel Latour ◽  
Angeles Blanco
Keyword(s):  
Paper Mill ◽  
Ph Adjustment ◽  
Paper Mill Effluent ◽  
Kinetics Studies ◽  
Silica Removal ◽  
Industrial Water Use ◽  
Optimum Ph ◽  
Initial Ph ◽  
Equilibrium And Kinetics ◽  
Kinetics Of

Effluent reuse is a common practice for sustainable industrial water use. Salt removal is usually carried out by a combination of membrane processes with a final reverse osmosis (RO). However, the presence of silica limits the RO efficiency due to its high scaling potential and the difficulty of cleaning the fouled membranes. Silica adsorption has many advantages compared to coagulation and precipitation at high pHs: pH adjustment is not necessary, the conductivity of treated waters is not increased, and there is no sludge generation. Therefore, this study investigates the feasibility of using pseudoboehmite and its calcination product (γ-Al2O3) for silica adsorption from a paper mill effluent. The effect of sorbent dosage, pH, and temperature, including both equilibrium and kinetics studies, were studied. γ-Al2O3 was clearly more efficient than pseudoboehmite, with optimal dosages around 2.5–5 g/L vs. 7.5–15 g/L. The optimum pH is around 8.5–10, which fits well with the initial pH of the effluent. The kinetics of silica adsorption is fast, especially at high dosages and temperatures: 80–90% of the removable silica is removed in 1 h. At these conditions, silica removal is around 75–85% (<50 mg/L SiO2 in the treated water).

Meso tetrakis ortho-, meta-, and para-N-alkylpyridiniopor-phyrins: kinetics of copper(II) and zinc(II) incorporation and zinc porphyrin demetalation

2003 ◽  
Vol 07 (03) ◽  
pp. 139-146 ◽  
Author(s):  
Peter Hambright ◽  
Ines Batinić-Haberle ◽  
Ivan Spasojević
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Effective Charge ◽  
Methyl Ethyl ◽  
Ionic Strength Dependence ◽  
Zinc Porphyrin ◽  
Cationic Porphyrin ◽  
Strength Dependence ◽  
Acid Catalyzed ◽  
Kinetics Of

The relative reactivities of the tetrakis( N -alkylpyridinium- X - yl )-porphyrins where X = 4 (alkyl = methyl, ethyl, n -propyl) , X = 3 (methyl) , and X = 2 (methyl, ethyl, n -propyl, n -butyl, n -hexyl, n -octyl) were studied in aqueous solution. From the ionic strength dependence of the metalation rate constants, the effective charge of a particular cationic porphyrin was usually larger when copper(II) rather than zinc(II) was the reactant. The kinetics of ZnOH + incorporation and the acid catalyzed removal of zinc from the porphyrins in 1.0 M HCl were also studied. In general, the more basic 4- (para-) and 3- (meta-) isomers were the most reactive, followed by the less basic 2- (ortho-) methyl to n -butyl derivatives, with the lipophilic ortho n -hexyl and n -octyl porphyrins the least reactive.

Kinetics and mechanism of oxidation of DL-α-alanine by permanganate ion in acid perchlorate media

1991 ◽  
Vol 69 (12) ◽  
pp. 2018-2023 ◽  
Author(s):  
Refat M. Hassan
Keyword(s):  
Amino Acids ◽  
Ionic Strength ◽  
Acid Solution ◽  
Second Order ◽  
Perchloric Acid Solution ◽  
Oxidation Reduction ◽  
Initial Stage ◽  
Aqueous Perchloric Acid ◽  
Mechanism Of Oxidation ◽  
Kinetics Of

The kinetics of permanganate oxidation of DL-α-alanine in aqueous perchloric acid solution at a constant ionic strength of 2.0 mol dm−3 has been investigated spectrophotometrically. The reaction was found to show second-order kinetics overall with respect to each of the reactants in the slow initial stage; the second-order kinetics are not, however, maintained throughout the relatively fast final stage of reaction. The added salts lead to the prediction that Mn(III) and (or) Mn(IV) play a very important role in the reaction kinetics. A tentative mechanism consistent with the kinetics is discussed. Key words: kinetics, oxidation, reduction, amino acids, permanganate.

Effect of ionic strength on the aggregation kinetics of the amidated amyloid beta peptide Aβ (1-40) in aqueous solutions

2017 ◽  
Vol 228 ◽  
pp. 98-107 ◽  
Author(s):  
Adriana Campos-Ramírez ◽  
Maripaz Márquez ◽  
Liliana Quintanar ◽  
Luis F. Rojas-Ochoa
Keyword(s):  
Ionic Strength ◽  
Aqueous Solutions ◽  
Amyloid Beta ◽  
Amyloid Beta Peptide ◽  
Aggregation Kinetics ◽  
Beta Peptide ◽  
Kinetics Of
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