• Resources Recycling
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• v.13 no.6
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• pp.43-48
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• 2004

For the separation of neodymium from NdFeB permanent magnet scrap, the scrap was roasted for oxidizing, and leached with acetic acid followed by fractional crystallization for selective separation. From the analysis results of the leached solution, the optimum condition for the recovery of neodymium was found that leaching temperature, leaching time and pulp density are 80$^{\circ}C$, 3 hours, and 35%, respectively. At this optimum condition, more than 90% of neodymium could be recovered. Concentration of neodymium acetate in acetic acid. The optimum condition for the recovery of neodymium acetate crystal from the leached solution was that the initial leaching solution was evaporated until the remaining volume was about 1/5 of the initial volume. At this condition, 67.5% of neodymium was recovered from the leached solution. The neodymium remaining in the concentrated solution was recovered by reacting it with oxalic acid.

• Resources Recycling
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• v.26 no.1
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• pp.37-42
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• 2017

It has been reported that aqueous indirect carbonation process of calcium silicate mineral could be one of the most promising methods for $CO_2$ sequestration. The process consists of two main steps, extraction of Ca from calcium silicate and carbonation of the extracted solution by $CO_2$. Many types of acids such as HCl and $HNO_3$ can be used in the extraction step of the process. In the case of using aqueous acetic acid solution as the extraction solvent, acetic acid can be reproduced at the carbonation step of the extracted solution by $CO_2$ and recycled to extraction step for reuse it. Industrial by-products such as iron and steel slags are potential raw materials of the indirect carbonation process due to their high contents of calcium silicate. In this study, in order to examine the extraction efficiency of domestic electric arc furnace steel slag by aqueous acetic acid solution, extraction experiments of the slag were performed by using the aqueous acetic acid solutions of varying extraction conditions ; acetic acid concentrations, extraction temperatures and times.

• Resources Recycling
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• v.22 no.1
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• pp.64-71
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• 2013

Mineral carbonation has been proposed as a possible way for $CO_2$ sequestration. The electric arc furnace slags consist of calcium, magnesium and aluminum silicates in various combinations. If they could be used instead of natural mineral silicates for carbonation, considerable energy savings and $CO_2$ emissions reductions could be achieved. Indirect aqueous carbonation of the slags consists of two steps, extraction of calcium and carbonation. Acetic acid leaching of electric arc furnace slags had been already studied to extract Ca in them, but it was reported that the carbonation of the extracted $Ca^{2+}$ in the leached solution would suffer from too slow kinetics, even at high pressure of $CO_2$. In this work, to develop more efficient extraction of the electric arc furnace slags, hydrochloric acid leaching to separate calcium from them was studied, and the results were compared with the acetic acid ones. The phase boundary between $Ca^{2+}$ and $CaCO_3$ in the solution with pH was determined by thermodynamic calculations. Hydrochloric acid was more effective than acetic acid for the extraction of Ca in electric arc furnace slag, and there is a possibility to recycle an unreacted hydrochloric acid in the leached solution by electrolysis or evaporation.

• Microbiology and Biotechnology Letters
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• v.9 no.4
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• pp.191-196
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• 1981

In order to utilize the Koryangju distillers' grain for the acetic acid fermentation, the extracting methods and effects of the extracts on the fermentations were investigated. The result obtained are as follows. 1. Cold extracting method by which the distillers grain is extracted with 3 times of water for 60 hours at room temperature was better than hot extracting method in terms of the fermentation rate and the quality of vinegar product. 2. Optimum conditions and some results of surface fermentation based on the medium added by the extracts are as follows, optimum amount of the extracts to be added to the medium is 20-30% of total media; acetic acid production rate at log phase was 0.16g/100$m\ell$, hr.; recovery was 91.17%; and the time of 40 hours was required for the completion of fermentation. 3. Organoleptic quality of the vinegar which is produced by adding the extracts was superior to two commercial products examined.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2002.05a
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• pp.127-131
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• 2002

Migration of di-(ethylhexyl)phthalate (DEHF) from PVC food packaging materials detected plasticizer into food simulanting solvents(4% Acetic acid, 8% Ethanol, 50% Ethanol, 95% Ethanol, Heptane) were studied. For executing this study ,2 PVC food packaging materials detected DEHP were used. Analysis was by GC-FID and GC-MSD(selected ion monitoring) for DEHP, and optimized for quantification of plasticizer. The recovery of DEHP into food simulanting solvents were min. 87.4${\pm}$ 3.6 ∼ max. 109.9 ${\pm}$ 10.7% respectively. Following exposure to food simulants 95% Ethanol for 24hours at 60$^{\circ}C$ the migration results of 1020.90 ${\pm}$ 10.15$\mu\textrm{g}$/g, 563.54 ${\pm}$ 5.60$\mu\textrm{g}$/dm$^2$and 73.51 ${\pm}$ 5.09$\mu\textrm{g}$/g 149.22 ${\pm}$ 10.34$\mu\textrm{g}$/dm$^2$were detected from the container for lunch and for stock fish respectively.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.5
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• pp.342-351
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• 2014

The present paper investigates the performance of direct wet mineral carbonation technology to fix carbon dioxide ($CO_2$) from relatively high $CO_2$ concentration feeding gas using wollastonite ($CaSiO_3$)-water (and 0.46 M acetic acid) suspension solution. To minimize the energy consumed on the process, the carbonation in this work is carried out at atmospheric pressure and slightly higher room temperature. As a result, carbon fixation is confirmed on the surface of $CaSiO_3$ after carbonation with wollastonite-water suspension solution and its amount is increased according to the $CO_2$ composition in the feeding gas. The leaching and carbonation ratio of wollastonite-water suspension system obtained from the carbonation with 50% of $CO_2$ composition feeding gas is 13.2% and 10.4%, respectively. On the other hand, the performance of wollastonite-acetic acid in the same condition is 63% for leaching and 1.39% for carbonation.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.4
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• pp.151-160
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• 2006

Anaerobic treatment of landfill leachate was studied to investigate the behaviors of pollutant and the characteristics of microorganism for 10 months. The upflow anaerobic sludge blanket (UASB) reactor achieved about 90% chemical oxygen demand (COD) removal at organic loading rates(OLR) up to $20kgCOD/m^3.d$. At higher OLR ($8-20kgCOD/m^3.d$), the propionate concentration increased, indicating that converting propionate to acetate was the rate-limiting step. Nevertheless, increase in the precipitate inside and on the surface of granules as well as on the wall of the reactor resulted in operational problems. The main inorganic precipitate in the granule was calcium compound. Although specific methanogenic activity (SMA) was not affected seriously in this study, metals had to be removed prior to anaerobic treatment so as to be free from the excessive inorganic accumulation that resulted in operational problems.

• Journal of Food Hygiene and Safety
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• v.3 no.2
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• pp.53-58
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• 1988

This study was carried out to discuss a colorimetric method for the determination of nitrite in meat products issued by the Ministry of Health and Social Affaires of Korea (1985). 1) The recovery rates of nitrite of test solution extracted in the room temperature were higher than those obtained by the heating extraction. 2) In the room temperature, samples prepared with the sUce were more effective than the blendina method and the distlled water as extractina solvent for nitrite was more effective tban tbe phospbate buffer solution. 3) The extracting time showed that thirty minutes were enough to extract nitrite and the diazotizingcoupling reagents, 30% of sulfanilamide and N-l-naphthylethyienediamine were better than others. 4) The nitrite in a test soiution greatly decreased when the solution was distilled. In this case, the test solution should be used as a control. 5) Ten minutes were enough to couple nitrite.

• Journal of Nutrition and Health
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• v.43 no.6
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• pp.551-560
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• 2010

The study aim was to investigate the effects of three types of mulberry products on the blood glucose and lipid statuses and peroxidative state under diabetic condition. The three types were mulberry liquor prepared by adding 30% ethanol to the crushed fresh fruit, mulberry wine and vinegar by fermentation. For diet experiment the mulberry liquor (M-Liquor), wine (M-Wine), and vinegar (M-Vinegar) were prepared as powders by freeze-drying of the respective product and were added to the diet at the level of 1% and mulberry fruit powder (M-Powder) at the level of 5%. Sprague- Dawley female rats weighing $150{\pm}10\;g$ were randomly assigned to one normal group, and five diabetic groups induced by one intraperitoneal injection of streptozotocin (STZ) at the level of 50 mg/kg. The normal and diabetic control (DM-Control) groups were fed diet without the mulberry products. During twenty-one days of experimental diet, blood glucose was maintained at a low level in the M-Liquor group compared with the DM-Control group. However, serum insulin level was higher in both M-Liquor and M-Vinegar groups after the experimental diet period. Serum levels of total cholesterol and triglyceride (TG) were lower in M-Liquor but HDL-/total cholesterol ratios were higher in the four M groups. The TG liver level was lower in M-Powder and M-Vinegar groups but the cholesterol level was lower in M-Powder than in the DM-Control group. Serum levels of thiobarbituric acid reactive substances were not different among the groups but the liver levels of these substances were lower in the four M groups than in DM-Control. Serum GOT and GPT levels were not changed by the mulberry products. These results indicated that mulberry liquor is the most effective among the four mulberry products for normalizing blood glucose and lipid status and that all the mulberry products were effective in enhancing antioxidant defense in the diabetic state.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.3
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• pp.372-376
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• 2009

Physicochemical changes in persimmon were examined during natural organic acid fermentation. Major organic acids in raw persimmon juices were lactic acid (980 mg%) and acetic acid (245 mg%). The content of acetic acid was continuously increased during the whole period of fermentation up to 3 years. Glucose was the dominant free sugar, but the content was decreased after 20 days of fermentation. Most of the glucose was converted to ethanol until 40 days after initiation of acid fermentation. L- and a values of Hunter's color in fermented persimmon juice, which was naturally exuded from persimmon fruit as fermentation continued, increased gradually, while b value decreased. Acetic acid (1584 mg%) was the most abundant organic acid followed by lactic acid (712 mg%) and citric acid (48 mg%) in a persimmon fruit juice after completion of 3 year fermentation. A minute amount of residual free sugars, mainly glucose, even after 3 years of fermentation may cause changes in quality characteristics while storage for edible use.