• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.539-546
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• 2019

Global warming has mentioned as one of the international problems and these researches have conducted. Carbon Capture, Utilization and Storage (CCUS) technology has improved due to increasing importance of reducing emission of carbon dioxide. Among of various CCUS technologies, mineral carbonation can converted $CO_2$ into high-cost materials with low energy. Existing researches has been used ions extracted solid wastes for mineral carbonation but the procedure is complicated. However, the procedure using seawater is simple because it contained high concentration of metal cation. This research is a basic study using seawater-based wastewater for mineral carbonation. 3 M Monoethanolamine (MEA) was used as $CO_2$ absorbent. Making various concentrations of seawater solution, simulated seawater powder was used. Precipitated metal carbonate salts were produced by mixing seawater solutions and $rich-CO_2$ absorbent solution. They were analyzed by X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Thermogravimetric Analysis (TGA) and studied characteristic of producing precipitated metal carbonate and possibility of reusing absorbent.

• Resources Recycling
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• v.31 no.3
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• pp.61-72
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• 2022

We investigated the electrochemical behavior of Sn (93.0 %)-Ag (4.06 %)-Cu (0.89 %) during electrolysis of Pb-free solder waste to recover tin and silver. A thin strip of the solder waste produced by high-temperature melting and casting was used as a working electrode to perform electrochemical analysis. During anodic polarization, the current peak of an active region decreased with an increase in the concentration of sulfuric acid used as an electrolyte. This resulted in the electro-dissolution of the working electrode in the electrolyte (1.0 molL^-1 sulfuric acid) for a constant current study. The study revealed that the thickening of an anode slime layer at the working surface continuously increased the electrode potential of the working electrode. At 10 mAcm^-2, the dissolution reaction continued for 25 h. By contrast, at 50 mAcm^-2, a sharp increase in the electrode potential stopped the dissolution in 2.5 h. During dissolution, silver enrichment in the anode slime reached 94.3% in the 1 molL^-1 sulfuric acid electrolyte containing a 0.3 molL^-1 chlorine ion, which was 12.7% higher than that without chlorine addition. Moreover, the chlorine enhanced the stability of the dissolved tin ions in the electrolyte as well as the current efficiency of tin electro-deposition at the counter electrode.

• Journal of the Korean Geotechnical Society
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• v.28 no.3
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• pp.67-75
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• 2012

This paper presents an environment-friendly sand cementation method by precipitating calcium carbonate using plant extracts. The plant extracts contain urease like $Sporosarcina$ $pasteurii$, which can decompose urea into carbonate ion and ammonium ion. It can cause cementation within sand particles where carbonate ions decomposed from urea combine with calcium ions dissolved from calcium chloride or calcium hydroxide to form calcium carbonate. Plant extracts, urea and calcium chloride or calcium hydroxide were blended and then mixed with Nakdong River sand. The mixed sand was compacted into a cylindrical specimen and cured for 3 days at room temperature ($18^{\circ}C$). Unconfined compression test, SEM and XRD analyses were carried out to evaluate three levels of urea concentration and two different calcium sources. As urea concentration increased, the unconfined compressive strength increased up to 10 times those without plant extracts because calcium carbonate precipitated more, regardless of calcium source. It was also found that the strength of specimen using calcium chloride was higher than that of specimen using calcium hydroxide.

• Journal of the Korean GEO-environmental Society
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• v.7 no.4
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• pp.35-41
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• 2006

This paper analyzed elution and ingredients of soil components which consist of soil and rocks in 6 regions in Yeongyang and Cheongsong to identify substantial matters that cause muddy water in Imha reservoir. We identified that more than 80% of major ingredients in collected soil and rocks are vermiculite(V), illite(I), kaolinite(Ka), quartz(Q), feldspar(F). Sodium and calcium are eluted in large quantities from soil of Sanseong and Cheongki. When calcium is in contact with water, much ions are eluted rapidly. We confirmed these ions are alkali minerals rising pH. We consider clay components distributed in Yeongyang as major cause of muddy water and rising pH of Imha reservoir because its ingredient calcite easily is dissolved in rainwater and splits other mineral particles into ${\mu}m$ sized particles.

• Journal of Korea Soil Environment Society
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• v.4 no.1
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• pp.57-68
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• 1999

Adsorption behavior of metal elements onto soil minerals such as illite, halloysite. zeolite(clinoptilolite). and goethite was comparatively investigated at $25^{\circ}C$ using pollutant water collected from a gold-bearing metal mine. Speciation of solutions reacted was determined by WATEQ4F program, indicating that most of metal ions exist as free ions and that there is little difference in chemical species and their relative abundances between initial soultion and reacted solutions. The experimental data exhibit that the adsorption extent of elements varies depending on mineral types and reaction time. The adsorption process practically took place within one hour, with Fe and As significantly removed from solutions. On the whole, halloysite is regarded as the most effective adsorbent among minerals used in the experiment. Adsorption properties of alkali elements do not consistent with a manner predicted from hydrated ionic radii.

• The Journal of the Petrological Society of Korea
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• v.10 no.3
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• pp.222-232
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• 2001

Secondary ion mass spectrometry (SIMS) uses focused high-speed primary ions to produce secondary ions from sample surface that are analyzed through a mass filter. SIMS is often called as ion microprobe, since it offers a micrometer-scale spatial resolution. Although the precision and accuracy of SIMS are not as good as many conventional mass spectrometers, it has several advantages such as small sample-size requirement, high spatial resolution and capability of in-situ analysis. In the field of geochemistry/cosmochemistry, SIMS is widely used for (1) stable isotope geochemistry of H, C, O, S, etc., (2) geochronology of U/Th-bearing minerals, (3) lateral distribution of trace elements in a mineral, and (4) discovery of presolar grains and investigation of their isotopic compositions.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.2
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• pp.97-107
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• 2017

Columnar aerosol properties retrieved from solar radiation were investigated at the Yongin (YGN) SKYNET site over seven years from October 2008 to October 2015. Hourly averages were calculated when the data were available, and back trajectories were calculated to examine the effects of regional transport. Data recovery rate was low at 6.6%, primarily because solar radiation was measured only under daytime clear-sky conditions. Mean values of the fine-mode volume fraction (FMVF) as well as its seasonal variation were similar to those of $PM_{2.5}/PM_{10}$ although the coarse-mode fraction of column aerosols tended to be slightly larger. The values of single scattering albedo (SSA) and FMVF were lower in spring due to the effects of mineral dust, and higher in summer due to secondarily-formed inorganic ions. Back trajectories were grouped into five clusters according to the directions of transport paths. Aerosol loading was highest for Cluster 2 from the northwest, but SSA and FMVF were not particularly high or low because aerosols were composed of various materials with different properties. Aerosol loading was lowest for Cluster 5 from the Pacific Ocean passing through the south end of Japan, whose SSA and FMVF were highest as secondarily-formed inorganic ions were mixed.

• Archives of Plastic Surgery
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• v.35 no.4
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• pp.407-412
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• 2008

Purpose: Hydrofluoric acid(HF) is one of the most dangerous mineral acids with the dissociated fluoride ions. The initial corrosive burn is caused by free hydrogen ion, and the second and more severe burn is caused by penetration of fluoride ions into subcutaneous tissues. Silver is a cation producing dressing, an effective antimicrobial agent, but older silver-containing formulations are rapidly inactivated by wound environment, requiring frequent replenishment. But, $Acticoat^{(R)}$ is a relatively new form of silver dressing which helps avoid the problems of earlier agents. The aim of this study is to evaluate effects of $Acticoat^{(R)}$, silver-containing dressing on the treatment for HF injury wound. Methods: From september 2006 to september 2007, the study was carried out with 10 patients who had HF partial thickness burns. $Acticoat^{(R)}$ dressing and 10% calcium gluconate wet gauze dressings in 10 cases. As a principle, in the emergency treatment, partial or complete removal of the nail and early bullectomy along with copious washing with normal saline was done, depending on the degree of HF invasion of the wound. Wound was dressed with $Acticoat^{(R)}$ and 10% calcium gluconate solution. The effect of dressing was investgated by serial bacterial culture and wound exudates assessment. Results: We therefore reviewed 10 cases of HF-induced chemical burns and treatment principle. The 10 cases who came to the hospital nearly immediately after the injury healed completely without sequelae. Conclusion: As the industrial sector develops, the use of HF is increasing more and more, leading to increased incidences of HF-induced chemical burns. The education of patients regarding this subject should be empathized accordingly. In conclusion, $Acticoat^{(R)}$ dressing is a better choice for HF partial thickness burn injuries because of shorter healing time, less pain and more comfortable dressing.

• Journal of the Mineralogical Society of Korea
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• v.11 no.1
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• pp.20-31
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• 1998

Adsorption of metal elements onto illite and halloysite was investigated at $25^{\circ}C$ using pollutant water collected from the gold-bearing metal mine. Incipient solution of pH 3.19 was reacted with clay minerals as a function of time: 10 minute, 30 minute, 1 hour, 12 hour, 24 hour, 1 day, 2 day, 1 week, and 2 week. Twenty-seven cations and six anions from solutions were analyzed by AAs (atomic absorption spectrometer), ICP(induced-coupled plasma), and IC (ion chromatography). Speciation and saturation index of solutions were calculated by WATEQ4F and MINTEQA2 codes, indicating that most of metal ions exist as free ions and that there is little difference in chemical species and relative abundances between initial solution and reacted solutions. The adsorption results showed that the adsorption extent of elements varies depending on mineral types and reaction time. As for illite, adsorption after 1 hour-reaction occurs in the order of As>Pb>Ge>Li>Co, Pb, Cr, Ba>Cs for trace elements and Fe>K>Na>Mn>Al>Ca>Si for major elements, respectively. As for halloysite, adsorption after 1 hour-reaction occurs in the order of Cu>Pb>Li>Ge>Cr>Zn>As>Ba>Ti>Cd>Co for trace elements and Fe>K>Mn>Ca>Al>Na>Si for major elements, respectively. After 2 week-reaction, the adsorption occurs in the order of Cu>As>Zn>Li>Ge>Co>Ti>Ba>Ni>Pb>Cr>Cd>Se for trace elements and Fe>K>Mn>Al, Mg>Ca>Na, Si for major elements, respectively. No significant adsorption as well as selectivity was found for anions. Although halloysite has a 1:1 layer structure, its capacity of adsorption is greater than that of illite with 2:1 structure, probably due to its peculiar mineralogical characteristics. According to FTIR (Fourier transform infrared spectroscopy) results, there was no shift in the OH-stretching bond for illite, but the ν1 bond at 3695 cm-1 for halloysite was found to be stronger. In the viewpoint of adsorption, illite is characterized by an inner-sphere complex, whereas halloysite by an outer-sphere complex, respectively. Initial ion activity and dissociation constant of metal elements are regarded as the main factors that control the adsorption behaviors in a natural system containing multicomponents at the acidic condition.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.296-300
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• 2002

Bacterial cell surface components are the major factors responsible for pathogenesis and bioremediation. In particular, the surface of a Gram-negative bacterium cell has a variety of components compared to that of a Gram-positive cell. In our previous study, we isolated an isogenic mutant of Bradyrhizobium japonicum, which exhibited altered cell surface characteristics, including an increased hydrophobicity. Polyacrylamide gel electrophoretic analysis of the lipopolysaccharide (LPS) in the mutant demonstrated that the O-polysaccharide part was completely absent. Meanwhile, a gel permeation chromatographic analysis of the exopolysaccharide (EPS) in the mutant demonstrated that it was unaltered. Since LPSs are known to have several anion groups that interact with various cation groups and metal ions, the mutant provided an opportunity to examine the direct role of LPS in metal binding by B. japonicum. Using atomic absorption spectrophotometry, it was clearly demonstrated that LPS was involved in metal binding. The binding capacity of the LPS mutant to various metal ions $(Cd^{2+},\;Cu^{2+},\;Pb^{2+},\;and\;Zn^{2+})$ was 50-70% lower than that of the wild-type strain. Also, through an EPS analysis and desorption experiment, it was found that EPS and centrifugal force had no effect on the metal binding. Accordingly, it would appear that LPS molecules on B. japonicum effect the properties, which precipitate more distinctly metal-rich mineral phase.