Electrochemical degradation of perfluorooctanoic acid (PFOA) by Yb-doped Ti/SnO2–Sb/PbO2anodes and determination of the optimal conditions

RSC Advances ◽  
2015 ◽  
Vol 5 (103) ◽  
pp. 84856-84864 ◽  
Author(s):  
Qianchi Ma ◽  
Lei Liu ◽  
Wei Cui ◽  
Ruifeng Li ◽  
Tingting Song ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Perfluorooctanoic Acid ◽  
Optimal Conditions ◽  
Electrochemical Degradation

Model aqueous solutions of perfluorooctanoic acid (PFOA, 100 mg L−1) were electro-oxidized in a homemade container.

Cadmium Removal by Flotation from Diluted Aqueous Solutions. Determination of the Optimum Separation Conditions

2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Adrian Turtureanu
Keyword(s):  
Aqueous Solutions ◽  
Molar Ratio ◽  
Optimal Conditions ◽  
Air Flow Rate ◽  
Cadmium Removal ◽  
Initial Concentration ◽  
Dilute Aqueous Solutions ◽  
Very High ◽  
Optimum Separation

The paper presents the removal of cadmium by flotation from dilute aqueous solutions, at a laboratory scale, using an anionic collector (oleic acid). The optimum values of the main parameters influencing this process were determined: pH of Cd(II) solutions, molar ratio collector:Cd(II), air flow rate, flotation time and initial concentration of Cd(II). Using these optimal conditions, a very high removal degree of cadmium (over 99%) was obtained.

Kinetic of degradation of two azo dyes from aqueous solutions by zero iron powder: determination of the optimal conditions

2012 ◽  
Vol 40 (1-3) ◽  
pp. 137-143 ◽  
Author(s):  
Mohammad Reza Samarghandi ◽  
Mansur Zarrabi ◽  
Abdeltif Amrane ◽  
Mohammad Noori Sepehr ◽  
Mehdi Noroozi ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Iron Powder ◽  
Azo Dyes ◽  
Optimal Conditions

LUMINESCENT DETERMINATION OF SUGAR IN NATURAL HONEY

2020 ◽  
Vol 0 (4) ◽  
pp. 29-32
Author(s):  
B.M. GAREEV ◽  
◽  
A.M. ABDRAKHMANOV ◽  
G.L. SHARIPOV ◽  
◽  
...  
Keyword(s):  
Quantum Dots ◽  
Laboratory Test ◽  
Aqueous Solutions ◽  
Analytical Method ◽  
Sugar Content ◽  
Carbon Quantum Dots ◽  
Photoluminescence Intensity ◽  
Sucrose Content ◽  
Natural Honey

The photoluminescence of carbon quantum dots synthesized from natural honey and mixtures of honey and sugar has been studied. An increase in the sugar content leads to a decrease in the photoluminescence intensity without changing the shape of the luminescence spectrum of these quantum dots aqueous solutions, which is associated with a decrease in the yield of their synthesis in the sugar presence. The discovered effect can be used to detect sugar in honey. When examining five different market samples of flower honey using this method, two of them showed a significant decrease in the photoluminescence intensity. A laboratory test for compliance with GOST 19792-2017 Standard requirements established an excess of the sucrose content in these samples. Luminescent determination of sugar in honey does not require complicated equipment and can be used to develop a new analytical method for determining the sugar content in counterfeit natural honey.

Spectrophotometric study of the complexation equilibria of cadmium ions with 5-bromo and 5-chloro derivatives of 2-(2-pyridylazo)-5-diethylaminophenol (BrPADAP, ClPADAP)

1983 ◽  
Vol 48 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Vlastimil Kubáň ◽  
Miroslav Macka
Keyword(s):  
Equilibrium Constants ◽  
Spectrophotometric Study ◽  
Graphical Analysis ◽  
Optimal Conditions ◽  
Cadmium Ions ◽  
Brij 35 ◽  
Ethanol Medium ◽  
Triton X ◽  
Derivatives Of

The composition, optical characteristics, molar absorption coefficients and equilibrium constants of the reactions of formation of the ML and ML2 complexes of both reagents with cadmium(II) ions were determined by graphical analysis and numerical interpretation of the absorbance-pH curves by the modified SQUAD-G program. Optimal conditions were proposed for the spectrophotometric determination of Cd in 10% v/v ethanol medium in the presence of 0.1% w/v Triton X-100 or 1% w/v Brij 35. BrPADAP and ClPADAP are the most sensitive spectrophotometric reagents for the determination of cadmium(II) ions (ε = 1.28-1.44 . 105 mmol-1 cm2 at 560 nm and pH 8.0-9.5) with a high colour contrast in the reaction (Δλmax ~117 nm) and a selectivity similar to that of other N-heterocyclic azodyes (PAR, PAN, etc.).

Spectrophotometric study of the reactions of lanthanoids with bromopyrogallol red in the presence of cation active tensides

1982 ◽  
Vol 47 (2) ◽  
pp. 503-508 ◽  
Author(s):  
Irena Němcová ◽  
Pavla Plocková ◽  
Tran Hong Con
Keyword(s):  
Absorption Spectra ◽  
Photometric Determination ◽  
Spectrophotometric Study ◽  
Ternary Complexes ◽  
Optimal Conditions ◽  
Bromopyrogallol Red ◽  
Binary Complexes

The absorption spectra of the binary complexes of lanthanoids with bromopyrogallol red were measured and the formation of ternary complexes with cation active tenside, Septonex, was studied. Optimal conditions were found for the formation of these complexes and the possibility of their use in the photometric determination of lanthanoids was demonstrated on several examples.

The polarographic and voltammetric determination of 2,6-dicyano-4-nitro-2'-acetylamino-4'-diethylaminoazobenzene

1990 ◽  
Vol 55 (6) ◽  
pp. 1508-1517 ◽  
Author(s):  
Jiří Barek ◽  
Dagmar Civišová ◽  
Ashutosh Ghosh ◽  
Jiří Zima
Keyword(s):  
Azo Dye ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Determination Limit ◽  
Polarographic Reduction ◽  
Hanging Mercury Drop Electrode ◽  
Optimal Conditions ◽  
Pulse Polarography ◽  
Pulse Voltammetry

The polarographic reduction of the title azo dye was studied and optimal conditions were found for its analytical utilization in the concentration range 1 . 10-6 - 1 . 10-7 mol l-1 using differential pulse polarography and 1 . 10-6 - 1 . 10-8 mol l-1 using fast scan differential pulse voltammetry or linear scan voltammetry at a hanging mercury drop electrode. When the latter technique is combined with adsorptive accumulation of the studied substance on the surface of the hanging mercury drop, the determination limit can be further decreased to 3 . 10-9 mol l-1.

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.

Manufacturing Process for Extracting Essential Oils from White Pepper (Piper nigrum L.) by Hydrodistillation Technique

2019 ◽  
Vol 298 ◽  
pp. 89-93 ◽  
Author(s):  
Thien Hien Tran ◽  
Thi To Quyen Ngo ◽  
Thi Kim Ngan Tran ◽  
Tri Duc Lam ◽  
Tan Phat Dao ◽  
...  
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Manufacturing Process ◽  
Oil Extraction ◽  
Piper Nigrum ◽  
Optimal Conditions ◽  
Distillation Process ◽  
White Pepper ◽  
Oil Performance

Vietnam is the world's leading country in growing and producing pepper trees. In this study, we attempted the optimization of white pepper essential oil extraction. The obtained oil was then subject to determination of constituent composition via GC-MS method. The essential oil performance achieved 3.6% by hydro-distillation process with optimal conditions (25 grams of fresh pepper, size 18, 120 minutes extraction, 130°C). A total of 23 volatile constituents were identified from the white pepper essential oil, with the major components being 27.4% of Limonene, 3-Carene 22,928%, Sabinene 17,622%, β-pinene 10.068%, α-Pinene 5.426%.

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