scholarly journals INVESTIGATION OF KINETIC COEFFICIENTS OF ELECTRIC HYPERFILTRATION EXTRACTION OF CHEMICAL SUBSTANCES FROM ANILINE-CONTAINING MANUFACTURING PROCESS SOLUTIONS

2017 ◽  
Vol 60 (5) ◽  
pp. 74
Author(s):  
Sergey I. Lazarev ◽  
Konstantin S. Lazarev ◽  
Olga A. Kovaleva ◽  
Vadim G. Kazakov ◽  
Alexandr E. Strelnikov
Keyword(s):  
Sulfuric Acid ◽  
Current Density ◽  
Manufacturing Process ◽  
Water Solution ◽  
Sulfuric Acid Concentration ◽  
Hindrance Factor ◽  
Specific Flow ◽  
Kinetic Coefficients ◽  
Extraction Factor ◽  
Process Solutions

The data on extraction factor; hindrance factor and solvent specific flow value during electric hyperfiltration extraction of substances from aniline-containing manufacturing process solutions are obtained in this study. The interpretation of experimental materials (extraction factor; hindrance factor and solvent specific flow) in a dependence on current density; concentration; nature of dissolved substance and semipermeable membrane type is presented as well. It was established that extraction factor and hindrance factor for aniline-containing substances is increased due to the growth of current density and sulfuric acid concentration. Solvent specific flow value is increased under current density elevation; but it is decreased in response to concentration growth. The treatment of aniline-water solution with sulfuric acid results in hindrance factor increasing with the growth of sulfuric acid concentration in aniline-water solution on MGA-100 and OPM-K membranes which is explained by pH reduction of solution. Besides; dissociation degree and solubility of weak bases such as aniline elevate; Gibbs energy common value is decreased under absorption; which leads to reduction of aniline sorption by membranes. The presence of sulfuric acid in aniline-water solution brings about the formation of more complex space structures. These substances are retained by membrane better due to its higher dissociation degree; better water solubility; larger molecular size and more branched structure. The increasing in sodium chloride and sodium sulfate concentrations results in the decrease in its hindrance factors and solvent specific flow value through semipermeable membranes of MGA-100 and OPM-K types.Forcitation:Lazarev S.I.; Lazarev К.S.; Kovaleva О.А.; Каzakov V.G.; Strelnikov А.Е. Investigation of kinetic coefficients of electric hyperfiltration extraction of chemical substances from aniline-containing manufacturing process solutions. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 5. P. 74-80

scholarly journals STUDIES OF KINETICS AND STRUCTURAL CHARACTERISTICS OF ELECTROBAROMEMBRANE PURIFICATION OF RINSING WATERS OF PRODUCTION OF 2,2'-DIBENZOTHIAZOLILEDISULPHIDE

2018 ◽  
Vol 59 (2) ◽  
pp. 34 ◽  
Author(s):  
Sergeiy I. Lazarev ◽  
Sergeiy V. Kovalev ◽  
Vadim G. Kazakov
Keyword(s):  
Pore Radius ◽  
Structural Characteristics ◽  
Experimental Studies ◽  
Polymeric Materials ◽  
Hindrance Factor ◽  
Radius Of Gyration ◽  
Chemical Additives ◽  
Specific Flow ◽  
X Ray Scattering ◽  
Kinetic Coefficients

The results of experimental studies are presented for the kinetic characteristics of the membranes of electrobaromembrane  purification  of rinsing waters of electrochemical synthesis of 2,2' - dibenzothiazoliledisulphide used as a corrosion inhibitor and chemical additives for the production of polymeric materials. The experimental studies for the determination the pore radius of the membranes were carried out by the method of low-angle X-ray scattering. The data obtained on the hindrance factor, specific flow, pore radius and radius of gyration allow to predict and to calculate the kinetic coefficients of electrobaromembrane process of purification of rinsing waters of 2,2' -2,2'- dibenzothiazoliledisulphide production.

scholarly journals Effective Recovery Process of Copper from Waste Printed Circuit Boards Utilizing Recycling of Leachate

JOM ◽  
2020 ◽  
Author(s):  
Joona Rajahalme ◽  
Siiri Perämäki ◽  
Roshan Budhathoki ◽  
Ari Väisänen
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Printed Circuit Boards ◽  
Sulfuric Acid Concentration ◽  
Recovery Process ◽  
Copper Recovery ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Acid Consumption

AbstractThis study presents an optimized leaching and electrowinning process for the recovery of copper from waste printed circuit boards including studies of chemical consumption and recirculation of leachate. Optimization of leaching was performed using response surface methodology in diluted sulfuric acid and hydrogen peroxide media. Optimum leaching conditions for copper were found by using 3.6 mol L−1 sulfuric acid, 6 vol.% hydrogen peroxide, pulp density of 75 g L−1 with 186 min leaching time at 20°C resulting in complete leaching of copper followed by over 92% recovery and purity of 99.9% in the electrowinning. Study of chemical consumption showed total decomposition of hydrogen peroxide during leaching, while changes in sulfuric acid concentration were minor. During recirculation of the leachate with up to 5 cycles, copper recovery and product purity remained at high levels while acid consumption was reduced by 60%.

scholarly journals Corrosion Behavior of AA 1100 Anodized in Gallic-Sulfuric Acid Solution

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 405
Author(s):  
Marlon L. Mopon ◽  
Jayson S. Garcia ◽  
Dexter M. Manguerra ◽  
Cyril John C. Narisma
Keyword(s):  
Corrosion Resistance ◽  
Sulfuric Acid ◽  
Acid Solution ◽  
Gallic Acid ◽  
Acid Concentration ◽  
Sulfuric Acid Solution ◽  
Current Density ◽  
Electrochemical Impedance ◽  
Anodized Aluminum ◽  
The Common

Sulfuric acid anodization is one of the common methods used to improve corrosion resistance of aluminum alloys. Organic acids can be added to the sulfuric acid electrolyte in order to improve the properties of the anodized aluminum produced. In this study, the use of gallic acid as an additive to the sulfuric acid anodization of AA1100 was explored. The effect of varying anodization current density and gallic acid concentration on the properties of anodized aluminum samples was observed using electrochemical impedance spectroscopy, linear polarization, and scanning electron microscopy. It was observed that the corrosion resistance of samples anodized in gallic-sulfuric acid solution at 10 mA·cm−2 is lower than samples anodized in sulfuric acid. It was also observed that higher anodization current density can lead to lower corrosion resistances for aluminum samples anodized in gallic-sulfuric acid solution. However, samples anodized at 5 mA·cm−2 and at a gallic acid concentration of 5 g·L−1 showed better corrosion performance than the samples anodized in sulfuric acid only. This suggests that the use of low amounts of gallic acid as an additive for sulfuric acid anodization can lead to better corrosion resistances for anodized aluminum.

scholarly journals Release of reducing sugars from water hyacinth by thermochemical and enzymatic hydrolysis

2021 ◽  
Vol 6 (1) ◽  
pp. 156-164
Author(s):  
Jessica E. Guzmán-Pérez ◽  
◽  
Oscar J. Salinas-Luna ◽  
Ernesto Favela-Torres ◽  
Nohemi López-Ramírez ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Enzymatic Hydrolysis ◽  
Acid Concentration ◽  
Water Hyacinth ◽  
Dry Matter ◽  
Eichhornia Crassipes ◽  
Reducing Sugars ◽  
Sulfuric Acid Concentration ◽  
Raw Material ◽  
Thermochemical Pretreatment

Water hyacinth (Eichhornia crassipes) is considered a pernicious herb in many parts of the world due to its rapid growth. However, for its high content of cellulose and hemicellulose, it could be considered as raw material to produce fermentable sugars. In this work, the effect of sulfuric acid concentration by thermochemical pretreatment and enzymatic hydrolysis on the release of sugars from water hyacinth was evaluated. Initially, the effect of the sulfuric acid concentration from 1.5 to 9% at 120 ºC was evaluated. With 1.5%, the release of reducing sugars was 160 milligrams of reducing sugars per gram of dry matter (mg red-sug/g dm). After the thermochemical pretreatment, the enzymatic hydrolysis with the cellulase complex (NS22086) allowed obtaining a reducing sugars concentration up to 317 mg red-sug/g dm. These thermochemical and enzymatic approaches to recover reducing sugars from water hyacinth is promising and should be evaluated for bioprocess using reducing sugars as the main source of carbon, such as bioethanol production.

scholarly journals New particle formation in the sulfuric acid–dimethylamine–water system: reevaluation of CLOUD chamber measurements and comparison to an aerosol nucleation and growth model

2018 ◽  
Vol 18 (2) ◽  
pp. 845-863 ◽  
Author(s):  
Andreas Kürten ◽  
Chenxi Li ◽  
Federico Bianchi ◽  
Joachim Curtius ◽  
António Dias ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Detection Threshold ◽  
Sulfuric Acid Concentration ◽  
Water System ◽  
Particle Formation ◽  
New Particle Formation ◽  
Flow Tube ◽  
Aerosol Model ◽  
Wide Range ◽  
Good Agreement

Abstract. A recent CLOUD (Cosmics Leaving OUtdoor Droplets) chamber study showed that sulfuric acid and dimethylamine produce new aerosols very efficiently and yield particle formation rates that are compatible with boundary layer observations. These previously published new particle formation (NPF) rates are reanalyzed in the present study with an advanced method. The results show that the NPF rates at 1.7 nm are more than a factor of 10 faster than previously published due to earlier approximations in correcting particle measurements made at a larger detection threshold. The revised NPF rates agree almost perfectly with calculated rates from a kinetic aerosol model at different sizes (1.7 and 4.3 nm mobility diameter). In addition, modeled and measured size distributions show good agreement over a wide range of sizes (up to ca. 30 nm). Furthermore, the aerosol model is modified such that evaporation rates for some clusters can be taken into account; these evaporation rates were previously published from a flow tube study. Using this model, the findings from the present study and the flow tube experiment can be brought into good agreement for the high base-to-acid ratios (∼ 100) relevant for this study. This confirms that nucleation proceeds at rates that are compatible with collision-controlled (a.k.a. kinetically controlled) NPF for the conditions during the CLOUD7 experiment (278 K, 38 % relative humidity, sulfuric acid concentration between 1 × 106 and 3 × 107 cm−3, and dimethylamine mixing ratio of ∼ 40 pptv, i.e., 1 × 109 cm−3).

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