• Resources Recycling
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• v.18 no.2
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• pp.56-61
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• 2009

The dissolution of domestic aluminum hydroxide of 99.7% purity has been performed with mineral and organic acid prior to the synthesis of aluminum compounds from aluminum solution. Mean particle size of aluminum hydroxide used in the work was $14.4{\mu}m$, $22.9{\mu}m$ and $62.3{\mu}m$, respectively and the effect of reaction temperature, concentration of acid and reaction time on the dissolution of aluminum hydroxide has been examined. As a result, the dissolution of aluminum hydroxide was increased with the concentration of HCl and more than 70% dissolution was obtained with 5 mole/l HCl at $70^{\circ}C$ for reaction time of 4 hr. As far as the dissolution of aluminum hydroxide with sulfuric acid was concerned, it was found that the optimum concentration of sulfuric acid was about 6 mole/l for the effective dissolution of aluminum hydroxide. When oxalic acid was used for the dissolution of aluminum hydroxide, nearly complete dissolution could be obtained by the dissolution for 16 hr with 1.0 mole/l oxalic acid at $90^{\circ}C$.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.2
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• pp.179-186
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• 2006

Chemical wastes are generated from nuclear facilities and R&D laboratories, but the uranium concentration in the final dried cake is evaluated into 11.2 Bq/g, which exceeds the exemption level of 10 Bq/g for each U isotopes, so the cake is categorized into a radioactive waste. Acid dissolution was applied to extract uranium from the waste sludge, and uranium adsorption on the dissolved solution was experimented by using IRN-77 and Diphosil bead. A large amount of resin was required to get above 80% of uranium removal, which was found to be due to a large amount of metal ions simultaneously dissolved from the precipitates with uranium. As an alternative method, acid dissolution is applied to the dewatered wet cake of the sludge, and the natural evaporation method is adopted for the dissolved solution. The uranium concentration of the dissolved solution was estimated to be 6.97E-01 Bq/ml, and the specific activity of the final waste sheets is evaluated to be 4.3 Bq/g. These results lead to the suggestion that the application of acid dissolution to the wet cake and the natural evaporation for the dissolved solution is an effective treatment method for chemical wastes containing uranium.

• The Korean Journal of Food And Nutrition
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• v.23 no.1
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• pp.45-51
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• 2010

The 2%, 3% of deer young antler, deer antler, oystershell, crabshell, eggshell were add into the 5%, 10%, 15% solution of glacial acetic acid and vinegar and after incubating it for 4 days at $30^{\circ}C$ respectively, solubility was analyzed. The result shows the difference was minute between glacial acetic acid and vinegar. In the 2% content of deer young antler, solubility was 42~47%, in the 3% content of it, solubility was 41~47%, with the acid concentration becoming higher, solubility increased slightly. In the 2% content of deer antler, solubility was 59~63%, in the 15% content of acid, solubility rather decreased. In the 2% content of oystershell, solubility was 85~96%, in the 3% content, solubility was 95~98%, in the 15% of acid density, it decreased. In the 2% content of crabshell, solubility was 79~88%, in the 3% content, solubility was 81~95%, and in case that acid density was high, solubility increased rather slightly. In the 2% content of eggshell, solubility was 84~96%, in the 3% content, solubility was 84~93%. When young deer antler and deer antler were heated for two hours at $100^{\circ}C$, solubility increased 19~24%, and in the case of crabshell, 10~11% increased. The above result and condition, and the result of pH and acidity don't have much influence on solubility. Thus, the 5% of acidity was enough to melt the 3% of sample. Highest were glacial acetic acid and vinegar in solubility to the various organic acid, and wax gourd vinegar melted the 85% of oystershell, the 78% of crabshell, the 28% of the deer young antler, and in the precipitation was made. Citric acid melted the 57% of deer antler, but it was precipitated with all other samples. Ascorbic acid melted the 92% of eggshell, and did the 37~54% of other samples.

• 발명특허
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• v.27 no.5 s.311
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• pp.68-74
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• 2002

본 발명은 키토산으로 이루어진 무수히 많은 갯수의 박막필름이 시트 평면에 수직, 수평 또는 경사 방향으로 일정간격의 공간을 유지하면서 적충되어서 라멜라구조를 형성하고 이 박막필름들이 일정한 간격으로 가지런히 나열되어 형성된 키토산 마이크로 플레이크로 이루어진 층상 격막시트에 관한 것이다. 두께 $1\mu{m}$내지 $50\mu{m}$로 라멜라구조를 이루는 키토산 박막필름이 $1\mu{m}$내지 $10000\mu{m}$의 공기간격을 두고 누적층을 형성하고 시트평면과$0^{\circ}C$내지$180^{\circ}C$사이의 일정 각도로 균일하게 배열되어 있어 수직, 수평 또는 경사방향으로 키토산 박막필름이 가지런히 배열되어 있는 키토산으로 조성된 수용성 층상 격막시트에 관한 것이다. 본 발명은 키토산을 약산성 액상에서 용해, 숙성 시켜 추출 고화 시키는 과정에서 수직, 수평 및 경사방향으로 키토산 마이크로 플레이크가 층상 라멜라구조를 이루는 키토산 격막시트를 형성시켜 줌으로 임상의학적 적용시 각각의 키토산 박막필름 사이의 균일한 공간으로 다양한 약물의 적용이 가능하며 특히 액상의 약재를 적용시 모세관의 원리에 따라서 약물이 원활하게 공급되는 약전성이 매우 우수하고 약물의 포집성이 획기적으로 부과된 재료로 사용될 수 있으며 키토산을 용해시켜 이용하는 산업에서 물에 신속하고 완전한 용해특성을 나타내는 키토산 원료물질로 사용될 수 있는 것이다.

• Food Science and Preservation
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• v.12 no.5
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• pp.501-506
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• 2005

This study was conducted to investigate the effect of organic acids on solubility of calcium. As a results, acetic and lactic acid showed the most excellent solubility of calcium. Calcium solubility was increased at initial total acid (4%) in citric acid but calcium was insoluble in tartaric acid. After solving, pH and residuals were decreased where as total acidity and calcium content were increased as increment of initial acidity of acetic and lactic acid. Calcium content in seaweed calcium and calcium carbonate were higher than that of nano calcium. Solubility of calcium was more conspicuous at lactic acid than acetic acid.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.93-105
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• 2012

Activity coefficients and solubilities of L-Valine and L-Proline in aqueous solutions containing each of four electrolytes such as NaCl, KCl, $NaNO_3$ and $KNO_3$ were measured at 298.15 K. The measurements of activity coefficients were carried out in the electrochemical cell coupled with two ion-selective electrodes (cation and anion), and the solubilities were measured by the gravimetric analysis of saturated solutions in equilibrium with the solid phase of amino acid. The measured activity coefficients of electrolytes and amino acids were correlated with the theoretical thermodynamic model presented in the previous work [Korean Chem. Eng. Res. 48(4), 519(2010)]. It was found that the activity coefficients of amino acids and electrolytes described based on the our previous model were well agreeable with experimental data. Also the experimental solubility data of L-Valine and L-Proline were successfully correlated with the thermodynamic relation mentioned in the previous work.

• The Journal of the Korean dental association
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• v.19 no.5 s.144
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• pp.433-437
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• 1981

• Journal of Korea Soil Environment Society
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• v.5 no.3
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• pp.55-64
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• 2001

Many organochlorine pesticides are persistent in the environment and have a tendency to bioaccumulate significantly through food chains. Aquatic environments are particularly more affected because the pesticides applied to agriculture systems are eventually carried into water bodies, through surface runoff, rivers, and groundwater flow. The objective of this paper is to study the effect of the coexistence of a heavy metal on the solubility enhancement of the two representative organochlorine pesticides, lindane and dieldrin, by humic acids. The solubility enhancement of pesticides by humic acid in a single system was compared with that in a binary system. The extent of solubility enhancement of lindane by humic acids was constant. while that of dieldrin by humic acids increased. Also, the solubility enhancement of dieldrin by humic acid with Pb decreased than that by humic acid without Pb.

• KSBB Journal
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• v.17 no.6
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• pp.515-519
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• 2002

The changes in the levels of total soluble protein and some free amino acids were investigated in germinating brown rice. Nongerminated (N) brown rice was germinated for 72 hrs by applying following solutions: 1) distilled water (W), 2) 50 ppm chitosan in 5 mM lactic acid (CL), and 4) 50 ppm chitosan in 5 mM glutamic acid (CG). The level of total soluble protein was higher in the N extract than those of W, CL and CG. Alanine levels were enhanced and aspartic acid levels were decreased significantly in the germinated brown rice, highest increases of alanine were found in the CG germinated brown rice. The levels of serine, decreased during germination in solutions W and CL, were increased significantly by germination in CG solution. The levels of essential amino acids, such as Iysine, isoleucine and methionine were also increased significantly by germination in CG solution. Our results show that the germination of brown rice with CG solution can significantly increase the levels of alanine and some other essential amino acids and can restore the serine level.

• Analytical Science and Technology
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• v.23 no.6
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• pp.511-517
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• 2010

Dissolution procedure of vanadium pentoxide, which is widely used as a catalyst for production of sulfuric acid or an oxide reaction of the numerous organic compounds, was investigated. Reagent of vanadium pentoxide was completely dissolved in aqua regia-$H_2O_2$-HF solution, but plate type of vanadium pentoxide sample was not clearly dissolved with mixed acids. Thus, in order to establish the dissolution procedure for plate type of vanadium pentoxide, the solubility of vanadium pentoxide was investigated through comparison of acid treatment-fusion and microwave digestion methods. The optimized acid for dissolution of vanadium compound was found to be mixing acids of aqua regia, $H_2O_2$ and HF. Acid-fusion and microwave digestion methods have a similar property in the solubility of vanadium compound, but the latter was more quick and convenient procedure. The content of vanadium pentoxide was found to be $97.9{\pm}0.9%$ using an inductively coupled plasma atomic emission spectrometer after dissolution of a sample with the microwave digestion system.