scholarly journals THE REACTION OF POTASSIUM PERSULPHATE WITH THIOGLYCOLIC ACID IN AQUEOUS SOLUTION

1959 ◽  
Vol 37 (6) ◽  
pp. 1082-1093 ◽  
Author(s):  
J. F. Henderson ◽  
C. A. Winkler
Keyword(s):  
Aqueous Solution ◽  
Acid Solution ◽  
Thioglycolic Acid ◽  
Second Order ◽  
Hydrogen Ion ◽  
Ferrous Ion ◽  
Ferric Ion ◽  
Ferric Ions ◽  
Solution Ph ◽  
Potassium Persulphate

The oxidation of thioglycolic acid to dithiodiglycolic acid by potassium persulphate in aqueous solution in the absence of iron did not yield reproducible results, but satisfactory data were obtained when ferrous or ferric ions were added to the system. The catalyst cycle appears to be that ferrous ion is oxidized by persulphate to ferric ion, and the ferric ion is reduced back to ferrous ion by thioglycolic acid. In the absence of persulphate, the reaction of ferric ion with thioglycolic acid in acid solution (pH < 3) was second order in both ferric ion and thioglycolic acid concentrations and was markedly inhibited by hydrogen ion.

Metal ion catalysis of the decomposition of transient 2-carboxy-2,5-cyclohexadienones in aqueous solution

1988 ◽  
Vol 66 (5) ◽  
pp. 1194-1198 ◽  
Author(s):  
Oswald S. Tee ◽  
N. Rani Iyengar
Keyword(s):  
Aqueous Solution ◽  
Carboxylic Acid ◽  
Metal Ion ◽  
Hydrogen Ion ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Ferric Ions ◽  
Bromide Ion ◽  
Metal Ion Catalysis ◽  
The Stability

Bromide ion induced debromination of the anion of 4-bromo-4-methyl-2,5-cyclohexadienone-2-carboxylic acid (1) is catalyzed by cupric ions and ferric ions. Similarly, the enolization of the anion of the benzocyclohexadienone 3, which is formed during the bromination of 1-naphthol-2-carboxylic acid, is catalyzed by some metal ions. The origin of the catalysis in these reactions is strong metal ion binding to the incipient dianion products that are of the salicylate type. Evidence for this is that the efficiency of the metal (and hydrogen) ion catalysis parallels the stability of the analogous complexes with the salicylate dianion.

scholarly journals Treatment of effluent from fertilizer industry by adsorption on willow sawdust-removal of Ni(II) and Cd(II) from the effluent

2021 ◽  
pp. 1-12
Author(s):  
Raafia Najam ◽  
Syed Muzaffar Ali Andrabi
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Cost ◽  
Second Order ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
The World ◽  
Pseudo Second Order ◽  
Almost All ◽  
Willow Tree

Sawdust of willow has been investigated as an adsorbent for the removal of Ni(II), and Cd(II) ions from aqueous solution. Since willow tree is widely grown in almost all parts of Kashmir, it can be a common most easily available, sustainable, low cost adsorbent for the treatment of wastewaters in this part of the world where growing industrialization is affecting water quality like elsewhere in the world. Therefore, it is worthwhile to investigate the potential of sawdust of willow tree as an adsorbent for the removal of Ni(II) and Cd(II) ions from aqueous solution as a first step. Batch experiments were conducted to study the effect of some parameters such as contact time, initial concentration of metal ions, solution pH and temperature. Langmuir and Freundlich models were employed for the mechanistic analysis of experimental data obtained. Results reveal that in our system adsorption follows the Langmuir isotherm. The maximum adsorption capacity of Ni(II) and Cd(II) were found to be 7.98 and 7.11 mg/g respectively at optimum conditions. The pseudo-first-order and pseudo-second-order models were employed for kinetic analysis of adsorption process. The adsorption process follows pseudo-second-order kinetics. The efficacy of the adsorbent in the treatment of effluent from fertilizer factory has been investigated and the results have been found encouraging.

Study of the kinetics and the adsorption isotherm of cadmium(II) from aqueous solution using green algae (Ulva lactuca) biomass

2015 ◽  
Vol 72 (9) ◽  
pp. 1505-1515 ◽  
Author(s):  
H. Asnaoui ◽  
A. Laaziri ◽  
M. Khalis
Keyword(s):  
Aqueous Solution ◽  
Metal Ions ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Ulva Lactuca ◽  
Order Kinetic ◽  
Solution Ph ◽  
Algae Biomass ◽  
Pseudo Second Order

Batch experiments were conducted to study the adsorption of hazardous cadmium onto low-cost algae biomass in aqueous solution with respect to concentration of adsorbate, adsorbent dosage, contact time, solution pH and temperature. Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and the isotherm constants were determined. The activation energy of adsorption was also evaluated for the adsorption of cadmium onto Ulva lactuca biomass. Experimental data were tested in terms of biosorption kinetics using pseudo-first-order and pseudo-second-order kinetic models. The results showed that the biosorption processes of Cd(II) followed well pseudo-second-order kinetics. Langmuir and Freundlich models were applied to describe the biosorption isotherm of the metal ions by Ulva lactuca biomass. Langmuir model fitted the equilibrium data better than the Freundlich isotherm. The biosorption capacity of Ulva lactuca biomass for cadmium was found to be 3.02 mg/g at pH 5.60 min equilibrium time and 20 °C. The mean free energy which was calculated was 6.24 kJ/mol for Cd(II) biosorption, which shows that the adsorption is physical. The calculated thermodynamic parameters (ΔG0, ΔH0 and ΔS0) showed that the biosorption of Cd(II) onto Ulva lactuca biomass was feasible, spontaneous and exothermic under examined conditions. The results indicate that algae Ulva lactuca could be employed as a low-cost material for the removal of metal ions from aqueous solution.

KINETICS AND MECHANISM OF COMPLEX FORMATION BETWEEN ETHYLENE AND RUTHENIUM(II) CHLORIDE IN AQUEOUS SOLUTION

1966 ◽  
Vol 44 (4) ◽  
pp. 495-500 ◽  
Author(s):  
Jack Halpern ◽  
Brian R. James
Keyword(s):  
Aqueous Solution ◽  
Hydrochloric Acid ◽  
Complex Formation ◽  
Acid Solution ◽  
Chloride Ion ◽  
Initial Step ◽  
Hydrogen Ion ◽  
Π Complex ◽  
Kinetics Of ◽  
Aqueous Hydrochloric Acid Solution

The formation of a 1:1 π-complex between ethylene and ruthenium(II) in aqueous hydrochloric acid solution is described. The kinetics of the reaction were examined over a range of temperatures and of concentrations of ruthenium(II), ethylene, hydrogen ion, and chloride ion. The results suggest that complex formation proceeds through a stepwise (SN1) mechanism in which the initial step involves the dissociation of a chlororuthenate(II) complex.

Phosphate-containing metabolites switch on phosphorescence of ferric ion engineered carbon dots in aqueous solution

RSC Advances ◽  
2014 ◽  
Vol 4 (43) ◽  
pp. 22318-22323 ◽  
Author(s):  
Xiao Yan ◽  
Jin-Long Chen ◽  
Meng-Xiang Su ◽  
Fang Yan ◽  
Bo Li ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Human Blood ◽  
Carbon Dots ◽  
Room Temperature ◽  
Cost Effective ◽  
Human Blood Plasma ◽  
Ferric Ion ◽  
Ferric Ions ◽  
Room Temperature Phosphorescence ◽  
Atp Level

Room temperature phosphorescence of carbon dots readily engineered by ferric ions in aqueous solution was developed for a novel “off-to-on” approach for cost-effective estimation of ATP level in human blood plasma.

scholarly journals ADSORPTION CHARACTERISTICS OF ZIZYPHUS JUJUBA SEED SHELL ACTIVATED NANO POROUS CARBON FOR REMOVING COPPER (II) IONS FROM WASTEWATER

2016 ◽  
Vol 4 (12) ◽  
pp. 226-241
Author(s):  
K Veeravelan ◽  
S Arivoli ◽  
V Marimuthu
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Solution Ph ◽  
Batch Mode ◽  
Zizyphus Jujuba ◽  
Pseudo Second Order ◽  
Nano Carbon

In the present study, adsorption of copper (II) ions from aqueous solution by Activated Zizyphus Jujuba shell Nano Carbon was investigated under batch mode. The influence of solution pH, sorbent dose, copper concentration, contact time and temperature was studied. The copper adsorption was favored with maximum adsorption at pH 6.5. Sorption equilibrium time was observed in 60 min. The equilibrium adsorption data were correlated with Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Hurkins-Jura, Halsay, Radlich-Peterson, Jovanovic and BET isotherm models. The kinetics of the adsorption process was tested by pseudo-first-order, pseudo-second order, Elovich and Intra-particle diffusion models. It was shown that adsorption of copper could be described by the pseudo-second order kinetic model. Thermodynamic parameters such as Gibbs free energy (ΔG0), the enthalpy (ΔH0) and the entropy change of sorption (ΔS0) have also been evaluated and it has been found that the adsorption process was spontaneous, feasible and endothermic in nature. The results indicated that Activated Zizyphus Jujuba shell Nano Carbon can be used as an effective and low-cost adsorbent to remove copper (II) from aqueous solution.

scholarly journals Bioremediation of Ni2+, Cd2+ and Pb2+ from aqueous solution using chemically modified Newbouldia Leavis seed pod. Kinetics and Intraparticle Diffusivities.

2021 ◽  
Vol 46 (2) ◽  
Author(s):  
O.K. Amadi ◽  
F.K. Ekuma ◽  
B. N. Uche
Keyword(s):  
Aqueous Solution ◽  
Sorption Process ◽  
Second Order ◽  
Order Kinetic ◽  
Solution Ph ◽  
First Order ◽  
Biosorption Process ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Kinetic Plots

This study investigates the biosorption of Ni2+, Cd2+ and Pb2+ from aqueous solution by modified Newbouldia Leavis seed pod. The modification was done by acid treating air-dried activated Newbouldia Leavis seed pod by dissolving it in excess 1.0 M Mercapto acetic acid (HSCH2COOH) solution, stirred for 30 minutes and left to stand for 24 hours at 30 oC, filtered off using WhatmanNo. 41 filter paper and were air dried. The effects of solution pH and contact time were evaluated. The results showed that maximum Cd2+ and Ni2+ adsorption of 7.9872 mg/g and 7.9809 mg/g respectively occurred at pH of 6.0 while that of Pb2+ was 8.0000 mg/g, at a pH of 4.0. The optimum time for maximum adsorption of the three heavy metal ions were 110 min. The kinetic data revealed that the sorption process could best be described by the pseudo – second order kinetic model. The R2 values for the pseudo – second order kinetic plots were unity and were higher than first order reversible model and pseudo – first order plots. Moreover, the values of qcal and qexp obtained for pseudo – second order plots were very close indicating that the biosorption process followed the pseudo-second order kinetics. However, the transport mechanism for the process involved both intra-particle and liquid film diffusion.

The potential of calcium thioglycollate and fibre protectants for use in chemical shearing

1981 ◽  
Vol 96 (1) ◽  
pp. 227-232
Author(s):  
B. J. McDonald ◽  
R. J. Bunch ◽  
P. S. Hopkins
Keyword(s):  
Aqueous Solution ◽  
Citric Acid ◽  
Acid Solution ◽  
Single Site ◽  
Preliminary Evaluation ◽  
Citric Acid Solution ◽  
Solution Ph ◽  
Pre Treatment ◽  
Optimum Relationship ◽  
Practical Implications

SUMMARYThe wool-severing properties of 2·8% aqueous solution of calcium thioglycollate were increased by 76% by dissolving the depilatory agent in a KCl-NaOH buffer of pH 12·5. The optimum Ca-thioglycollate concentration for defleecing was 3·6%. One ml of this solution defleeced an area of 12·1 cma.A comparison of five buffers and water as solvents for 3·6% Ca-thioglycollate indicated that the area of skin defleeced was directly related to solution pH and the stubble remaining appeared to be inversely related to solution pH. A KCl-NaOH buffer of pH 12·0 provided the optimum relationship between area defleeced (10·2 cm2/ml applied) and stubble (ca. 2 mm wool) remaining.Single site applications of 0·1–1·0 ml of defleecing agent at skin level were compared and it was shown that the application of 0·1 ml aliquots would require 320 ml solution to defleece an average-sized sheep.Preliminary evaluation of 6% formaldehyde buffered to pH 6 and a carbowax-citric acid solution of pH 2 showed that protection of fibres against dissolution by Cathioglycollate solutions can be sustained for 21 days. Pre-treatment with these compounds could therefore produce a protected band of wool immediately above the proposed site of wool dissolution.The practical implications of these findings are discussed with regard to a wool harvesting programme.

scholarly journals Ferrous and Ferric Ion-Facilitated Dilute Acid Pretreatment of Lignocellulosic Biomass under Anaerobic or Aerobic Conditions: Observations of Fe Valence Interchange and the Role of Fenton Reaction

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1427
Author(s):  
Hui Wei ◽  
Wei Wang ◽  
Peter N. Ciesielski ◽  
Bryon S. Donohoe ◽  
Min Zhang ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Fenton Reaction ◽  
Dilute Acid Pretreatment ◽  
Ferrous Ion ◽  
Ferric Ion ◽  
Dilute Acid ◽  
Ferric Ions ◽  
Ferrous Ions ◽  
Acid Pretreatment ◽  
Co Catalyst

Ferrous ion co-catalyst enhancement of dilute-acid (DA) pretreatment of biomass is a promising technology for increasing the release of sugars from recalcitrant lignocellulosic biomass. However, due to the reductive status of ferrous ion and its susceptibility to oxidation with exposure to atmosphere, its effective application presumably requires anaerobic aqueous conditions created by nitrogen gas-purging, which adds extra costs. The objective of this study was to assess the effectiveness of oxidative iron ion, (i.e., ferric ion) as a co-catalyst in DA pretreatment of biomass, using an anaerobic chamber to strictly control exposure to oxygen during setup and post-pretreatment analyses. Remarkably, the ferric ions were found to be as efficient as ferrous ions in enhancing sugar release during DA pretreatment of biomass, which may be attributed to the observation that a major portion of the initial ferric ions were converted to ferrous during pretreatment. Furthermore, the detection of hydrogen peroxide in the liquors after DA/Fe ion pretreatment suggests that Fenton reaction chemistry was likely involved in DA/Fe ion pretreatments of biomass, contributing to the observed ferric and ferrous interchanges during pretreatment. These results help define the extent and specification requirements for applying iron ions as co-catalysts in DA pretreatments of biomass.

Sign in / Sign up

Export Citation Format

Share Document