A Heat Conduction Microcalorimeter for the Determination of the Immersion Heats of Activated Carbon into Phenol Aqueous Solutions

2003 ◽  
Vol 31 (4) ◽  
pp. 385-397 ◽  
Author(s):  
Liliana Giraldo ◽  
José I. Huertas ◽  
Alexander Valencia ◽  
Juan Carlos Moreno
Keyword(s):  
Activated Carbon ◽  
Heat Conduction ◽  
Aqueous Solutions

scholarly journals Separation Cum Pre-Concentration Technique for Determination of Uranium in Sea, Brine and Ground Water at Nano to Sub nanogram Levels

2020 ◽  
pp. 302-312
Author(s):  
Leela Gopal ◽  
V. V. Hanuman ◽  
G. Chakrapani
Keyword(s):  
Activated Carbon ◽  
Aqueous Solutions ◽  
Ground Water ◽  
Contact Time ◽  
Sea Water ◽  
Cost Effective ◽  
Powdered Activated Carbon ◽  
Concentration Technique ◽  
Led Fluorimetry

Investigations were carried out for separation/pre concentration of uranium from aqueous solutions of different TDS using Powdered Activated Carbon (PAC). Parameters like amount of PAC, contact time, pH, volume of solutions and reagents for desorption were optimized. The sorption of uranium is more than 95% at pH 4-5 using 0.5 gram PAC with a contact time of 10 minutes.  The sorbed uranium on PAC is recovered using 0.8N HNO<sub>3</sub> and determined by LED Fluorimetry.  Method was successfully applied to ground water, sea water and brine water.  Methodology is simple, selective, cost effective with minimal skills. RSD of the method varies ± 6-14 %.

scholarly journals Thermodynamic study of the interactions of salicylic acid and granular activated carbon in solution at different pHs

2017 ◽  
Vol 36 (3-4) ◽  
pp. 833-850 ◽  
Author(s):  
Valentina Bernal ◽  
Liliana Giraldo ◽  
Juan C Moreno-Piraján
Keyword(s):  
Salicylic Acid ◽  
Activated Carbon ◽  
Aqueous Solutions ◽  
Activated Carbons ◽  
Granular Activated Carbon ◽  
Molecular Size ◽  
Carbon Surface ◽  
Immersion Enthalpy ◽  
Inappropriate Use

The inappropriate use of pain medication has led to the appearance of salicylic acid molecules (aspirin’s metabolite excretion) in surface water, which causes problems for the environment. The adsorption process using activated carbon is one of the processes that is used for the removal of organic compounds present in the aqueous phase; however, the percentage of removal depends on the physicochemical properties of the adsorbent and the adsorbate such as: pore size, surface area, surface chemistry, molecular size and solubility. In this work, we have studied the adsorbent–adsorbate interactions through the determination of the immersion enthalpy of the activated carbon in salicylic acid aqueous solutions; due to the solute and activated carbon surface have functional groups capable of ionized with the pH, the adsorption study was carried out at pH 2, 7, and 11. The activated carbons selected for the study were a granular activated carbon and a reduced activated carbon to 1173 K; as the immersion liquid were used salicylic acid aqueous solutions with concentrations between 0.072 mmol/ l and 0.72 mmol/ l, the solutions at pH 2 and 11 were prepared with HCl and NaOH solutions, respectively. It was determined that the immersion enthalpy is between −7.39 J /g and −22.5 J/g for the reduced activated carbon and between −7.63 J/g and −16.73 J/g for the granular activated carbon.

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.

Examination of Conditions for the Determination of Carbamate Pesticides in Soils

1992 ◽  
Vol 57 (8) ◽  
pp. 1632-1638 ◽  
Author(s):  
Věra Tatarkovičová ◽  
Zdeněk Stránský
Keyword(s):  
Activated Carbon ◽  
Solvent Extraction ◽  
Soil Type ◽  
Extraction Procedure ◽  
Purification Procedure ◽  
Factors Affecting ◽  
Carbamate Pesticides ◽  
Rp Hplc ◽  
Extracting Solvent

The procedure for the determination of carbamate pesticides in soil was optimized. The following factors affecting the final results were investigated: extracting solvent, extraction procedure, extract purification procedure, and soil type. Triple extraction with acetone and purification of the extract on a two-stage purification column containing an activated carbon-silica gel 1+1 mixture were found optimal. The extracts after treatment were analyzed by RP-HPLC with UV detection. The method developed allows carbamate pesticides in soil to be determined at concentrations in excess of 30 μg kg-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.

scholarly journals Iron-modified activated carbon derived from agro-waste for enhanced dye removal from aqueous solutions

Heliyon ◽  
2021 ◽  
pp. e07191
Author(s):  
Fateme Barjasteh-Askari ◽  
Mojtaba Davoudi ◽  
Maryam Dolatabadi ◽  
Saeid Ahmadzadeh
Keyword(s):  
Activated Carbon ◽  
Aqueous Solutions ◽  
Dye Removal ◽  
Modified Activated Carbon
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