scholarly journals Remediation of scrap iron contaminated by odorants

Paliva ◽  
2021 ◽  
pp. 10-15
Author(s):  
Petr Buryan ◽  
Siarhei Skoblia
Keyword(s):  
Aqueous Solution ◽  
Gas Chromatography ◽  
Acetic Acid ◽  
Elevated Temperatures ◽  
Plastic Material ◽  
Sodium Perborate ◽  
Decomposition Time ◽  
Scrap Iron ◽  
Positive Effect ◽  
Remediation Process

In general it can be stated that the newly developed remediation process eliminates naturally applied natural gas odorant - tetrahydrothiophene with an aqueous solution of perborate with the addition of acetic acid at normal temperature by immersion of contaminated metal and plastic material. During a detail laboratory study, it was demonstrated by gas chromatography using a specific sulfur chemiluminescent detector that 1 kg of tetrahydrothiophene could be used to decontaminate 1 kg of tetrahydrothiophene 3.5 kg of sodium perborate in the presence of CH3COOH. The total oxidative decomposition time of the odorant occurred in about 20 hours. At elevated temperatures - 40° C - the process proceeds at a slightly higher rate. A higher ratio of perborate to tetrahydrothiophene also has a positive effect on the faster course and degree of decomposition.

scholarly journals Remediation of scrap iron contaminated by odorants

Paliva ◽  
2021 ◽  
pp. 10-15
Author(s):  
Petr Buryan ◽  
Siarhei Skoblia
Keyword(s):  
Aqueous Solution ◽  
Gas Chromatography ◽  
Acetic Acid ◽  
Elevated Temperatures ◽  
Plastic Material ◽  
Sodium Perborate ◽  
Decomposition Time ◽  
Scrap Iron ◽  
Positive Effect ◽  
Remediation Process

In general it can be stated that the newly developed remediation process eliminates naturally applied natural gas odorant - tetrahydrothiophene with an aqueous solution of perborate with the addition of acetic acid at normal temperature by immersion of contaminated metal and plastic material. During a detail laboratory study, it was demonstrated by gas chromatography using a specific sulfur chemiluminescent detector that 1 kg of tetrahydrothiophene could be used to decontaminate 1 kg of tetrahydrothiophene 3.5 kg of sodium perborate in the presence of CH3COOH. The total oxidative decomposition time of the odorant occurred in about 20 hours. At elevated temperatures - 40° C - the process proceeds at a slightly higher rate. A higher ratio of perborate to tetrahydrothiophene also has a positive effect on the faster course and degree of decomposition.

scholarly journals Experimental Investigation on the Cleaning Effect and Influence Rule of Hydrogen Peroxide–Acetic Acid on Lead–Bismuth Eutectic Alloy

2021 ◽  
Vol 9 ◽  
Author(s):  
Xi Huang ◽  
Bo Pang ◽  
Xuelong Zhou ◽  
Yuan Yin
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Gas Chromatography ◽  
Stainless Steel ◽  
Acetic Acid ◽  
Relative Mass ◽  
Special Treatment ◽  
Spent Fuel ◽  
Lead Bismuth Eutectic ◽  
Bismuth Alloy

During the refueling process of lead–bismuth eutectic (LBE)–cooled fast reactors, lead–bismuth alloy can easily adhere to the surface of the fuel rod clads when spent fuel assemblies are unloaded from the reactor core. For some designs, the lead–bismuth alloy attached on the spent fuel rods will be cleaned via physical or/and chemical methods prior to their transportation, storage, and reprocessing. In this article, the cleaning effect of a washing lotion composed of hydrogen peroxide (H2O2) aqueous solution and concentrated acetic acid (CH3COOH) as the main components on LBE was experimentally investigated. By adjusting the composition ratio of the washing lotion and the reaction temperature, the law of their influence on the cleaning effect of LBE was determined. The optimal washing lotion composed of 30 Vol% hydrogen peroxide aqueous solution as oxidant, 40 Vol% concentrated acetic acid as acid, and 30 Vol% ultrapure water as the solvent was proposed based on experimental investigations. The optimal working temperature range was also obtained. The reaction intermediate product was characterized with the XRD analysis in order to understand the reaction mechanism. The composition of the released gas (even in a slight amount) was also analyzed with gas chromatography. The hydrogen concentration in the released gas was found to be lower than the detection limit of gas chromatography (10 ppm). Since the explosion limits of hydrogen at atmospheric pressure are between 3.95 and 75.73 Vol%, the risk of possible hydrogen explosion is concluded to be extremely low. Therefore, no special treatment of the released gas is required even in a large-scale industrial platform. Furthermore, corrosion effect of the washing lotion on austenitic stainless steel components was tested as well and found to be negligibly small. The relative mass loss of the thin-walled stainless steel samples immersed in the washing lotion was found to be less than 0.5% after an experimental duration of 144 h, which facilitates sufficient cleaning time in future industrial applications.

scholarly journals Effects of process factors on performances of liquid membrane-based transfer of indole-3-acetic acid

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ioana Diaconu ◽  
Oana Cristina Pârvulescu ◽  
Sorina Laura Topală ◽  
Tănase Dobre
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Mass Transfer ◽  
Acetic Acid ◽  
Liquid Membrane ◽  
Bulk Liquid ◽  
Feed Phase ◽  
Process Factors ◽  
Positive Effect ◽  
Indole 3 Acetic Acid

AbstractThe paper has aimed at studying the transfer of indole 3-acetic acid (IAA) from a feed aqueous solution to a stripping aqueous solution of NaOH using a chloroform bulk liquid membrane and trioctylamine (TOA) as a ligand (L). Initial molar concentrations of IAA in the feed phase, cIAA,F0 (10–4–10–3 kmol/m3), of TOA in the membrane phase, cL,M0 (10–2 and 10–1 kmol/m3), and of NaOH in the stripping phase, cNaOH,S0 (10–2 and 1 kmol/m3), were selected as process factors. Their effects on the final values of IAA concentration in the feed phase (cIAA,Ff) and stripping solution (cIAA,Sf), extraction efficiency (EF), distribution coefficient (KD), and recovery efficiency (ER) were quantified using multiple regression equations. Regression coefficients were determined from experimental data, i.e., cIAA,Ff,ex = 0.02–1 × 10–4 kmol/m3, cIAA,Sf,ex = 0.22–2.58 × 10–3 kmol/m3, EF,ex = 90.0–97.9%, KD,ex = 9.0–46.6, and ER,ex = 66.5–94.2%. It was found that cIAA,F0 had the most significant positive effect on cIAA,Ff and cIAA,Sf, whereas cNaOH,S0 had a major positive effect on EF, KD, and ER. A deterministic model based on mass transfer of IAA was developed and its parameters, i.e., mass transfer coefficient of IAA-L complex in the liquid membrane (0.82–11.5 × 10–7 m/s) and extraction constant (1033.9–1779.7 m3/kmol), were regressed from experimental data. The effect of cL,M0 on both parameters was significant.

scholarly journals Effects of Process Factors on Performances of Liquid Membrane-Based Transfer of Indole-3-Acetic Acid

2021 ◽  
Author(s):  
Ioana Diaconu ◽  
Oana Cristina Pârvulescu ◽  
Sorina Laura Topală ◽  
Tănase Dobre
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Mass Transfer ◽  
Acetic Acid ◽  
Liquid Membrane ◽  
Bulk Liquid ◽  
Feed Phase ◽  
Process Factors ◽  
Positive Effect ◽  
Indole 3 Acetic Acid

Abstract The paper has aimed at studying the transfer of indole 3-acetic acid (IAA) from a feed aqueous solution to a stripping aqueous solution of NaOH using a chloroform bulk liquid membrane and trioctylamine (TOA) as a ligand (L). Initial molar concentrations of IAA in the feed phase, cIAA,F0 (10-4-10-3 kmol/m3), of TOA in the membrane phase, cL,M0 (10-2 and 10-1 kmol/m3), and of NaOH in the stripping phase, cNaOH,S0 (10-2 and 1 kmol/m3), were selected as process factors. Their effects on the final values of IAA concentration in the feed phase (cIAA,Ff) and stripping solution (cIAA,Sf), extraction efficiency (EF), distribution coefficient (KD), and recovery efficiency (ER) were quantified using multiple regression equations. Regression coefficients were determined from experimental data, i.e., cIAA,Ff,ex=0.02-1×10-4 kmol/m3, cIAA,Sf,ex=0.22-2.58×10-3 kmol/m3, EF,ex=90.0-97.9%, KD,ex=9.0-46.6, and ER,ex=66.5-94.2%. It was found that cIAA,F0 had the most significant positive effect on cIAA,Ff and cIAA,Sf, whereas cNaOH,S0 had a major positive effect on EF, KD, and ER. A deterministic model based on mass transfer of IAA was developed and its parameters, i.e., mass transfer coefficient of IAA-L complex in the liquid membrane (0.08-1.15×10-6 m/s) and extraction constant (1033.9-1779.7 m3/kmol), were regressed from experimental data. The effect of cL,M0 on both parameters was significant.

scholarly journals Association Constant of Acetic Acid in 1.02 m NaCl Aqueous Medium at Elevated Temperatures and Pressures

1987 ◽  
Vol 42 (8) ◽  
pp. 849-852
Author(s):  
P. Becker ◽  
B. A. Bilal
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Association Constant ◽  
Elevated Temperatures ◽  
Concentration Cell ◽  
Pressure Concentration ◽  
Increasing Temperature ◽  
Apparent Association ◽  
High Temperature High Pressure ◽  
Apparent Association Constant

The association constant of acetic acid in 1.02 m (NaCl) aqueous solution has been determined potentiometrically at temperatures up to 260 °C and pressures up to 1005 bar. A high-temperature high-pressure concentration cell having two hydrogen electrodes has been used for the measurement. The apparent association constant Q′HAC increases with increasing temperature but decreases with increasing pressure: (Q′HAC)25 ° C, 108 bar = 2.86 · 104, (Q′HAC)25 ° C , 500bar = 2.7 · 104, (Q′HAC)200 °C, 500 bar = 4.65 · 104, (Q′HAC)26O °C, 1005 bar = 6.57 · 104 m−1.

STUDIES ON CONTINUOUS ADSORPTION OF ACETIC ACID FROM AQUEOUS SOLUTION USING RICE HUSK ADSORBENT

2018 ◽  
Vol 14 (1) ◽  
pp. 42
Author(s):  
S. V. A. R. SASTRY ◽  
SRI ADIBATLA ANUSHA ◽  
S. VARUN ◽  
◽  
◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Rice Husk ◽  
Continuous Adsorption

The role of acidity profile in the nanotubular growth of polyaniline

2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Elena Konyushenko ◽  
Miroslava Trchová ◽  
Jaroslav Stejskal ◽  
Irina Sapurina
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Reaction Temperature ◽  
Subsequent Growth ◽  
Subsequent Oxidation ◽  
Ammonium Peroxydisulfate ◽  
Aniline Oligomers ◽  
Positive Effect ◽  
Granular Morphology

AbstractConditions of polyaniline (PANI) nanotubes preparation were analyzed. Aniline was oxidized with ammonium peroxydisulfate in 0.4 M acetic acid. There are two subsequent oxidation steps and the products were collected after each of them. At pH > 3, neutral aniline molecules are oxidized to non-conducting aniline oligomers. These produce templates for the subsequent growth of PANI nanotubes, which takes place preferably at pH 2–3. At pH < 2, granular morphology of the conducting PANI is obtained. High final acidity of the medium should be avoided in the preparation of nanotubes, e.g., by reducing the amount of sulfuric acid which is a by-product. Reduction of the peroxydisulfate-to-aniline mole ratio was tested for this purpose in the present study. Lowering of the reaction temperature from 20°C to −4°C had a positive effect on the formation of nanotubes.

scholarly journals Perborate Oxidation of Substituted 5-Oxoacids in Aqueous Acetic Acid Medium: A Kinetic and Mechanistic Study

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
S. Shree Devi ◽  
B. Muthukumaran ◽  
P. Krishnamoorthy
Keyword(s):  
Acetic Acid ◽  
Acid Medium ◽  
Reaction Rate ◽  
Reaction Medium ◽  
Activation Parameters ◽  
Reaction Rates ◽  
Mechanistic Study ◽  
Aqueous Acetic Acid ◽  
Sodium Perborate ◽  
Acetic Acid Medium

Kinetics and mechanism of oxidation of substituted 5-oxoacids by sodium perborate in aqueous acetic acid medium have been studied. The reaction exhibits first order both in [perborate] and [5-oxoacid] and second order in [H+]. Variation in ionic strength has no effect on the reaction rate, while the reaction rates are enhanced on lowering the dielectric constant of the reaction medium. Electron releasing substituents in the aromatic ring accelerate the reaction rate and electron withdrawing substituents retard the reaction. The order of reactivity among the studied 5-oxoacids is p-methoxy ≫ p-methyl > p-phenyl > –H > p-chloro > p-bromo > m-nitro. The oxidation is faster than H2O2 oxidation. The formation of H2BO3+ is the reactive species of perborate in the acid medium. Activation parameters have been evaluated using Arrhenius and Eyring’s plots. A mechanism consistent with the observed kinetic data has been proposed and discussed. Based on the mechanism a suitable rate law is derived.

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