scholarly journals Recuperación de indio a partir de paneles LCD de desecho usando ácido como agente lixiviante

2020 ◽  
Author(s):  
◽  
Guadalupe Yunnuen Becerra Sánchez
Keyword(s):  
Acetic Acid ◽  
Fluid Layer ◽  
Liquid Crystal Display ◽  
Sodium Thiosulfate ◽  
Operating Conditions ◽  
Solid Sample ◽  
Secondary Process ◽  
Sodium Acetate Solution ◽  
Acetate Solution ◽  
Leaching Process

Technological advance has brought with it a high demand and the constant replacement of electronic devices. Many of these technological devices (e.g., cell phones, tablets, televisions, computers) use indium in the form of indium oxide and tin (ITO) for the manufacture of the liquid crystal display (LCD). Indium is an element that is not abundant in nature, it is obtained mainly through a secondary process in the extraction of zinc oxide. In 2019, about 760 metric tons of indium were produced worldwide (Garside, 2020). For all of the above, it has become necessary to propose novel methods for recovering indium from electronic waste. In this work, an indium recovery process is evaluated, which is viable both, from an economic and an environmental point of view. An indium leaching process is developed by using acetic acid as leaching agent. The LCD screens, mainly computer, were disassembled and reduced to a size <200 mesh, this through the use of a zircon pearl mill. According to the diagrams obtained from the MEDUSA program, leaching occurs at pH of 4, so it was adjusted with a sodium acetate solution. For each 5 g of solid sample, a solution of 250 ml of 0.5 M acetic acid was used, while 0.1 M sodium thiosulfate was used as a reducing agent. Tests were carried out at three different temperatures: 25 ºC, 60 ºC and 80 ºC, under the same operating conditions. At 80 ºC, the highest extraction of the species of interest was obtained after 24 h, which was 320 mg for each kg of solid sample. In this process of recovery of indium, an extraction percentage of approximately 70% was obtained. In order to explain the kinetics of the leaching process, the decreasing core kinetic model without ash formation was used. From this it was found that the stage that controls the process is the diffusion through the fluid layer, where according to the Damköhler number the process is controlled by the reaction on the solid surface.

Analytical Methods for Diethylstilbestrol in Feeds and Premixes

1966 ◽  
Vol 49 (5) ◽  
pp. 895-898
Author(s):  
Loyal R Stone
Keyword(s):  
Acetic Acid ◽  
Analytical Methods ◽  
Sodium Acetate ◽  
Buffer System ◽  
Official Method ◽  
Sodium Acetate Solution ◽  
Acetate Solution ◽  
Acid Buffer System ◽  
Acetic Acid Buffer

Abstract Methods are presented in which diethylstilbestrol is extracted from feeds in the Goldfisch apparatus, transferred into alkaline sodium acetate solution to avoid emulsions, and measured colorimetrically in a sodium acetate-acetic acid buffer system. The procedure is rapid, and results agree closely with those obtained by the official method. Procedures are also presented for determination of diethylstilbestrol in molasses and fat mixtures.

175. The precipitation of the proteins in milk. I. Casein. II. Total proteins. III. Globulin. IV. Albumin and Proteose-peptone

1938 ◽  
Vol 9 (1) ◽  
pp. 30-41 ◽  
Author(s):  
Samuel J. Rowland
Keyword(s):  
Acetic Acid ◽  
Total Protein ◽  
Trichloroacetic Acid ◽  
Sodium Acetate ◽  
Acetic Acid Solution ◽  
Acid Mixture ◽  
Sodium Acetate Solution ◽  
Acetate Solution ◽  
Maximum Precipitation ◽  
Proteose Peptone

Improved methods have been evolved for the separation of the total protein, casein, albumin, globulin, and proteose-peptone substances of milk.I. The use of acetic acid-sodium acetate solutions for the precipitation of casein is elucidated, and it is shown that the maximum precipitation of casein is rapidly effected from milk samples of varying casein content by the addition to 10 ml. of milk of about 80 ml. of water at 40° C. and 1·0 ml. of 10% acetic acid solution, followed, after 10 min., by 1·0 ml. of N sodium acetate solution.This maximum precipitation was found to be 1·0–1·4% greater than by Moir's method, and 2·4–3·8% greater than by the method of the Association of Oflicial Agricultural Chemists.A procedure is suggested for the determination of casein which avoids the tedious transfer and washing of the precipitate, and gives enhanced ease, accuracy and speed of working.II. The advantages of trichloroacetic acid for the precipitation of proteins in determinations of the total protein and the non-protein nitrogenous substances of milk are discussed.The trichloroacetic acid methods at present in use are shown not to give complete precipitation, and for this a rapid method employing, at room temperature, a final concentration of 12% acid in the milk-acid mixture is recommended.III. An accurate method for the precipitation of globulin uncontaminated with either albumin or casein is described.IV. Methods are given for the precipitation and separation of the albumin and proteose-peptone substances.

scholarly journals Structure of aqueous sodium acetate solutions by X-Ray scattering and density functional theory

2020 ◽  
Vol 92 (10) ◽  
pp. 1627-1641
Author(s):  
Guangguo Wang ◽  
Yongquan Zhou ◽  
He Lin ◽  
Zhuanfang Jing ◽  
Hongyan Liu ◽  
...  
Keyword(s):  
Sodium Acetate ◽  
Density Functional ◽  
Hydration Shell ◽  
Ion Pair ◽  
Water Molecules ◽  
Sodium Acetate Solution ◽  
Acetate Solution ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

AbstractThe structure of aq. sodium acetate solution (CH3COONa, NaOAc) was studied by X-ray scattering and density function theory (DFT). For the first hydrated layer of Na+, coordination number (CN) between Na+ and O(W, I) decreases from 5.02 ± 0.85 at 0.976 mol/L to 3.62 ± 1.21 at 4.453 mol/L. The hydration of carbonyl oxygen (OC) and hydroxyl oxygen (OOC) of CH3COO− were investigated separately and the OC shows a stronger hydration bonds comparing with OOC. With concentrations increasing, the hydration shell structures of CH3COO− are not affected by the presence of large number of ions, each CH3COO− group binds about 6.23 ± 2.01 to 7.35 ± 1.73 water molecules, which indicates a relatively strong interaction between CH3COO− and water molecules. The larger uncertainty of the CN of Na+ and OC(OOC) reflects the relative looseness of Na-OC and Na-OOC ion pairs in aq. NaOAc solutions, even at the highest concentration (4.453 mol/L), suggesting the lack of contact ion pair (CIP) formation. In aq. NaOAc solutions, the so called “structure breaking” property of Na+ and CH3COO− become effective only for the second hydration sphere of bulk water. The DFT calculations of CH3COONa (H2O)n=5–7 clusters suggest that the solvent-shared ion pair (SIP) structures appear at n = 6 and become dominant at n = 7, which is well consistent with the result from X-ray scattering.

Mitigating the Antimicrobial Activities of Selected Organic Acids and Commercial Sanitizers with Various Neutralizing Agents

2011 ◽  
Vol 74 (5) ◽  
pp. 820-825 ◽  
Author(s):  
YOEN JU PARK ◽  
JINRU CHEN
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Organic Acids ◽  
Shiga Toxin ◽  
Room Temperature ◽  
Sodium Thiosulfate ◽  
Antimicrobial Activities ◽  
Phosphate Buffered Saline ◽  
Lactic Acids

This study was conducted to evaluate the abilities of five neutralizing agents, Dey-Engley (DE) neutralizing broth (single or double strength), morpholinepropanesulfonic acid (MOPS) buffer, phosphate-buffered saline (PBS), and sodium thiosulfate buffer, in mitigating the activities of acetic or lactic acid (2%) and an alkaline or acidic sanitizer (a manufacturer-recommended concentration) againt the cells of Shiga toxin–producing Escherichia coli (STEC; n = 9). To evaluate the possible toxicity of the neutralizing agents to the STEC cells, each STEC strain was exposed to each of the neutralizing agents at room temperature for 10 min. Neutralizing efficacy was evaluated by placing each STEC strain in a mixture of sanitizer and neutralizer under the same conditions. The neutralizing agents had no detectable toxic effect on the STEC strains. PBS was least effective for neutralizing the activity of selected organic acids and sanitizers. Single-strength DE and sodium thiosulfate neutralized the activity of both acetic and lactic acids. MOPS buffer neutralized the activity of acetic acid and lactic acid against six and five STEC strains, respectively. All neutralizing agents, except double-strength DE broth, had a limited neutralizing effect on the activity of the commercial sanitizers used in the study. The double-strength DE broth effectively neutralized the activity of the two commercial sanitizers with no detectable toxic effects on STEC cells.

The Basis of Bentazon Antagonism on Sethoxydim Absorption and Activity

Weed Science ◽  
1989 ◽  
Vol 37 (3) ◽  
pp. 400-404 ◽  
Author(s):  
Gunawan Wanamarta ◽  
Donald Penner ◽  
James J. Kells
Keyword(s):  
Sodium Salt ◽  
Sodium Acetate ◽  
Tomato Fruit ◽  
Weak Acid ◽  
Antagonistic Effect ◽  
Hydroxyl Group ◽  
Sodium Acetate Solution ◽  
Acetate Solution ◽  
Spray Solution ◽  
Leaf Surfaces

The antagonistic effect of bentazon on sethoxydim adsorption and activity was studied in quackgrass. The diffusion of14C-sethoxydim into and through an isolated tomato fruit cuticle was inhibited in the presence of the sodium salt of bentazon. Bentazon also increased the partitioning of14C-sethoxydim into CH2Cl2and water; however, it decreased partitioning into ethyl acetate. Removal of epicuticular wax from quackgrass leaf surfaces did not prevent the antagonism. Addition of sodium acetate or sodium bicarbonate to the sethoxydim spray solution at 10 mM reduced uptake of14C-sethoxydim by quackgrass similar to the effect of bentazon. Sodium ions in the bentazon formulation appeared responsible for the antagonism by exchanging with the H+of the sethoxydim hydroxyl group to form a more polar sodium salt of sethoxydim. The addition of Li+, K+, Cs+, Ca++, and Mg++cations associated with a weak acid also reduced14C-sethoxydim absorption. Addition of organic acids to the spray solution overcame the antagonism by preventing the formation of sodium salt of sethoxydim. In the field, the addition of a 3000 ppm sodium acetate solution delivering 0.56 kg/ha produced the same antagonism as bentazon on quackgrass control with sethoxydim.

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