• Journal of Food Hygiene and Safety
• /
• v.17 no.4
• /
• pp.183-187
• /
• 2002

This study was performed to investigate the utility of egg-shell calcium with calcium soak egg-shell in the vinegar. We compared examination eluted quantity with ionization rate in each condition. The results were as follows. 1 The degree of elution and ionization of calcium was proportional to the amount of vinegar and added acetic acid in the vinegar for elution. And ionization rate was the most high in case of 200 ml vinegar volume. 2. fluted quantity were increased in the rank order to 4$0^{\circ}C$ > 3$0^{\circ}C$ > 2$0^{\circ}C$ by temperature but the rank order of ionization of calcium was 3$0^{\circ}C$ > 2$0^{\circ}C$ > 4$0^{\circ}C$ by temperature. The occurrence of unacceptable flavor resulting from the immersion at 4$0^{\circ}C$ was another obstacle to adopt. 3. Eluted quantity and ionization rate of the egg-shell calcium were appeared excellent in case of the brewage vinegar at ventilation condition. The case of brown rice vinegar did not show a considerable difference, but eluted quantity and ionization rate were appeared the most excellent to the other sample. 4. The optimum condition for elution and ionization of the egg-shell calcium was appeared Immersing egg-shells in the brewed rice-bran vinegar at 3$0^{\circ}C$ for three days.

• Proceedings of the KAIS Fall Conference
• /
• 2008.11a
• /
• pp.459-462
• /
• 2008

본 논문에서는 $10K_2O$-30CaO-$60P_2O_5$ mol%를 기본조성으로 하여 Fe, Cu, Zn의 미량성분을 첨가하여 유리를 제조하고 용출 특성을 평가 하였다. 제조된 유리는 미량성분의 첨가량에 따라 유리의 투명도가 변하는 것이 관찰되었다. 용출특성은 측정 4시간 뒤 pH값 증가되는 것으로 16시간 후 pH가 증가하는 것으로 관찰되었다. 여기서 pH의 증가는 염기성산화물이 용출되는 것으로, 감소는 $P_2O_5$구조인 망목형성구조가 붕괴되어지면서 산성이온이 용출되어지는 것으로 판단되어진다. ICP관찰시에는 함량이 증가하면서 K, Ca, P이온의 용출량이 감소되었고, Zn, Cu, Fe이온의 용출량이 증가하는 경향이 관찰되었다.

• Korean Journal of Mineralogy and Petrology
• /
• v.36 no.1
• /
• pp.33-40
• /
• 2023

Todorokite is a manganese oxide mineral containing Mg²⁺ in a tunnel structure in which MnO₆ octahedra share corners. In order to investigate the suitability and efficiency of high temperature-treated todorokite as a material for adsorption and fixation of Cs, Cs was ion exchanged and the amount of leached Cs from todorokite was measured. The todorokite used in this study was synthesized by transforming Na-birnessite to Mg-buserite and used as a precursor. After high temperature treatment, Cs exchanged todorokite changed to birnessite and hausmannite as the temperature increased. The amount of leached Cs was investigated for Cs exchanged todorokite which was reacted with distilled water and 1 M NaCl solution at different reaction times. In general, for the samples reacted with 1 M NaCl solution, the fixation of Cs was quite effective, although the amount of leached Cs was greater due to the ion exchange reaction with Na. As the treatment temperature increased, the amount of leached Cs increased and then decreased again, which was related to the mineral phases formed at each temperature. As birnessite was formed, the amount of leached Cs increased, but as birnessite decreased, that decreased again. As the mineral phase changed to hausemanite, the amount of Cs decreased rapidly. The results of our study show that Cs exchanged todorokite can be used as a material that effectively fixes Cs and prevents its diffusion by high temperature treatment.

• Korean Journal of Mineralogy and Petrology
• /
• v.36 no.4
• /
• pp.313-321
• /
• 2023

Numerous studies have investigated the adsorptive sequestration of radioactive cesium in the natural environment. Among these studies, adsorption onto minerals and high-temperature treatment stand out as highly effective, as demonstrated by the use of zeolite. In this study, cesium was ion-exchanged with birnessite and subsequently underwent high-temperature treatment up to 1100℃ to investigate both mineral phase transformation and the leaching characteristics of cesium. Birnessite has a layered structure consisting of MnO₆ octahedrons that share edges, demonstrating excellent cation adsorption capacity. The high-temperature treatment of cesium-ion-exchanged birnessite resulted in changes in the mineral phase, progressing from cryptomelane, bixbyite, birnessite to hausmannite as the temperature increased. This differs from the phase transformation observed in the tunneled manganese oxide mineral todorokite ion-exchanged with cesium, which shows phase transformation only to birnessite and hausmannite. The leaching of cesium from cesium-ion-exchanged birnessite was estimated by varying the reaction time using both distilled water and a 1 M NaCl solution. The leaching quantity changed according to the treatment temperature, reaction time, and type of reaction solution. Specifically, the cesium leaching was higher in the sample reacted with 1 M NaCl compared to the sample with distilled water and also increased with longer reaction time. For the samples reacted with distilled water, the cesium leaching initially increased and then decreased, while in the NaCl solution, the leaching decreased, increased again, and finally nearly stopped like the sample in the distilled water for the sample treated at 1100℃. These changes in leaching are closely associated with the mineral phases formed at different temperatures. The phase transformation to cryptomelane and birnessite enhanced cesium leaching, whereas bixbyite and hausmannite hindered leaching. Notably, hausmannite, the most stable phase occurring at the highest temperature, demonstrated the greatest ability to inhibit cesium leaching. This results strongly suggest that high-temperature treatment of cesium-ion-exchanged birnessite effectively immobilizes and sequesters cesium.

• Ecology and Resilient Infrastructure
• /
• v.5 no.1
• /
• pp.19-24
• /
• 2018

Water quality is affected by the pollutants flowing into rivers since the interaction between water bodies and sediments in various environmental conditions. Especially, accumulation of sediments increases in the stagnant water areas due to a relative long hydrological retention time in the water bodies. Therefore, it is an important factor of water quality to understand characterization of the material behavior in water bodies and sediments. In this study, the objective of the conditional experiments was small and medium sized streams located in Gyeonggi-do. To estimate how the changes of fluoride behavior, depending on the pH, ion type, concentration, and clay contents. The pH results showed a trend that adsorption amount of fluorine decreased and the dissolution of fluorine increased following by pH increasing. The concentration and type of ions results showed that $Cl^-$ and $SO{_4}^{2-}$ ions had no significant effect on the adsorption ability of fluorine, the amount of dissolution was increased because $OH^-$ ion had active competition with fluorine in the reaction. The ingredient of sediment results showed that the amounts of fluoride adsorption and dissolution were reduced in samples, which contain relatively large amounts of Silt and Clay components. This means that the environmental conditions of water bodies greatly affect the adsorption and dissolution of fluoride in the sediments, so that proper management of fluoride in the sediments must precede an understanding of the environmental conditions of the water bodies.

• Journal of Korea Foundry Society
• /
• v.43 no.5
• /
• pp.260-263
• /
• 2023

이 보고서에서는 무기 공정에서의 무기 인공 재생 모래의 특성을 중심으로 다음과 같이 정리할 수 있다. 1) ICP 발광 분광 분석을 통한 재생 모래의 Na⁺ 용출량, TP 휨강도 및 충전 밀동에는 높은 상관 관계가 확인되었다. 2) 현행 재생 방법 대비, 습식 연마 처리를 첨가함으로써 잔류 점결재가 제거되고 Na+ 용출량이 저감된 결과, 재생 모래의 TP 휨강도를 보다 개선 가능한 것이 확인되었다. 3) 재생 처리 공정 순서를 건식 연마 → 습식 연마 → 배소 처리로 함으로써, 가장 Na⁺ 용출량이 낮고, 높은 휨강도를 얻을 수 있는 것이 확인되었다. 4) 습식 연마 단계를 거치지 않고 배소 처리 온도와 처리 시간을 궁리함으로써 충분한 품질의 재생 모래를 얻을 수 있는 가능성이 시사되었다. 마지막으로, 무기 공정은 유기 공정에 비해 압도적으로 냄새가 적고 생산성이 높으며 인공 모래와의 병용을 통한 재생 처리시의 폐기물량 저감, 주조품의 고품질화 등 이점이 기대되는 공정이다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.2
• /
• pp.604-607
• /
• 2010

The glass formation and the dissolution property in $P_2O_5-K_2O$-FeO-CuO system were studied. In the batch process, the content of P2O5 was fixed at 60mol% and the other elements were varied from 10~40mol%. The prepared glasses were soaked in the D.I. water up to 13hr and the dissolution properties were investigated with the solutions sampled every 2 hr. The result shows that the $P_2O_5$ was leached out firstly from Phosphate glass system and then Cu and Fe ions were observed according to atmosphere change in solution. ICP shows that the dissolution amount in Phosphate was depended on the glass structure and the highest dissolution amount of CuO and FeO ions was observed when the 10mol% $K_2O$ was added in batch process.

• Journal of the Korean Wood Science and Technology
• /
• v.42 no.4
• /
• pp.460-466
• /
• 2014

To evaluate wood charcoal as raw material for mineral water production, dissolution of inorganic ions from charcoal to water, pH and adsorption ability of chlorine in water were investigated as main variables. More potassium ion was dissolved in water as higher temperature manufactured charcoal but other ions showed no difference with different charcoal making temperatures. Highest dissolved cation was potassium followed by calcium and sodium. Among wood species, charcoal from Quercus variabilis and Platanus occidentalis showed significantly higher potassium content in water than that of larch, red pine and white pine. Other cations had similar pattern to the potassium but their difference was not apparent as much as potassium. pH value of water treated with charcoal was higher for wood charcoals from Platanus occidentalis (pH 8.5) and Quercus variabilis (pH 8.4) which contained higher inorganic cations. In chlorine removal in water by charcoal, all wood charcoals showed greater chlorine removal than that of the control, but softwood charcoals resulted in higher removal than those of hardwoods. There was no significant difference in the dissolution of cations and pHs between particle charcoal and whole charcoal. With easy of control, whole charcoal is better for mineral water making raw material than particle charcoal does.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.16 no.2
• /
• pp.76-81
• /
• 2006

The leaching behavior of heavy metal ions with pH and colloid/interface property was analyzed by ICP and SEM. The heavy metals in EAF dust are 'amphoteric metal' and the heavy metal ions leached a little at pH 10. And the leaching concentrations of heavy metals at pH 12 were higher than the that at pH 8. The leaching concentrations of heavy metal ion were decreased with adding the clay to the EAF dust. Especially, the leaching concentrations of heavy metal ion were effectively decreased at pH 12. The observation of colloid/interface properties shows that the soluble silicon hydroxide from clay at pH 12 was precipitated at the surface of the heavy metal and clay particles. This silicon hydroxide precipitates were named the PSHP. The leaching concentrations of heavy metal ion were effectively decreased by the formation of PSHP when adding the clay to the EAF dust and controlling the pH of the slurry at 12.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.02a
• /
• pp.137-137
• /
• 2012

인공관절은 노인성 질환이나 자가 면역질환, 신체적인 외상 등으로 인하여 발생하는 관절의 손상 부위를 대체하기 위하여 고안된 관절의 인공 대용물이다. 인공 관절 중 인공 고관절의 경우 라이너(Liner)와 헤드(Head) 부분이 직접적인 마모 운동을 수행하게 되므로, 이 부분의 소재 특성에 따라 인공관절의 수명이 결정 되게 된다. 현재 헤드 소재로서는 Co-Cr-Mo 합금이, 라이너 소재로서는 고분자 소재인 UHMWPE (Ultra High Molecular Weight Polyethylene)가 주로 사용되고 있다. 이러한 MOP (Metal-On-Polymer) 구조의 인공관절의 경우, 충격흡수의 장점이 있는 반면, 관절 운동시 발생하는 UHMWPE 의wear debris에 의해 골용해가 발생하게 되어 인공관절의 수명이 저하되는 문제점이 있으며, 금속 헤드의 마모로 인한 금속이온의 용출은 세포 독성의 문제를 야기하여 인공관절의 수명을 저하시키는 또 다른 원인이 되고 있다. 따라서 본 연구에서는 PIII&D (Plasma Immersion Ion Implantation & Deposition) 공정을 이용하여 금속 (Co-Cr-Mo 합금)소재 위에 세라믹 (niobium nitride) 박막을 증착하여 상대재인 UHMWPE의 마모를 줄이고자 하는 연구를 진행하였다. 금속 소재 위에 증착된 세라믹 박막은 상대재인 UHMWPE의 마모량을 줄여줄 뿐만 아니라 금속이온의 용출을 막아준다는 장점이 있으나, 장시간의 마모 운동에 의하여 발생하는 박막의 박리 현상은 인공관절의 수명을 급격히 저하시키는 또 다른 원인이 된다. 이러한 단점을 해결하기 위하여, 박막의 증착 초기에 이온주입과 증착을 동시에 수행하는 dynamic ion mixing공정을 수행하였다. Dynamic ion mixing 공정을 수행함에 따라 박막과 금속 사이의 접착력이 증가하게 되어, UHMWPE의 마모량이 2배 가까이 감소하는 것을 확인할 수 있었으며, 장시간의 마모시험에서도 우수한 결과를 얻을 수 있었다. 또한 UHMWPE의 마모량을 감소시키기 위하여 박막을 증착하기 전에 금속 소재에 질소 이온주입을 수행하는 pre-ion implantation 공정을 도입하였다. 질소 이온주입 결과 Co-Cr-Mo 합금 표면에 부분적으로 CrN, Cr2N의 세라믹 상이 형성 되는 것을 확인할 수 있었으며, 그에 따라 UHMWPE의 마모량이 2배 이상 감소 되는 것을 확인 할 수 있었다.