• Journal of Conservation Science
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• v.38 no.2
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• pp.117-123
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• 2022

In this study, investigated the possibility of quantitatively and qualitatively analyzing Korean ancient glasses via Raman Spectroscopy. We subjected four categories of Korean traditional glasses, namely, lead-BaO, lead, potash, and soda glasses (3, 3, 10, and 10 pieces, respectively), to this analytical technique. The results showed significant differences between the stretching and bending Raman vibration regions corresponding to these different Korean ancient glass types. Specifically, the stretching vibration regions corresponding to lead-BaO and lead glasses showed peaks at 1040 and 1000 cm^-1, respectively; the stretching vibration region of normal glass appears at 1100 cm^-1. The bending vibration regions corresponding to potash and soda glass showed Raman peaks at 490 and 560 cm^-1, respectively. Furthermore, the Raman spectra of the lead and lead-BaO glasses showed red shifts, which depended on the amount of PbO present. Thus, our findings highlighted the possibility of quantitatively determining the amount of PbO, a major component of lead glasses, via Raman Spectroscopy.

• Resources Recycling
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• v.9 no.1
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• pp.44-51
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• 2000

Red mud is generated as a by-product in the production of $Al(OH)_{3}/Al_2O_3$ from bauxite ore. In this study the pellet-type adsorbents have been made from the red mud, and their adsorption capacities of heavy metal ions have been tested. The pellet-type adsorbents were synthesized to utilize the excellent adsorption capacity of the powder-type adsorbent for industrial application. The pellet-type adsorbents were prepared by mixing several kinds of additives with the red mud. It is found that the pellet-type adsorbent, made by sintering a mixture of red mud (96.0 wt%), polypropylene (2.5%), fly ash (0.5 w%), and sodium metasilicate(1.0 wt%) at $1200^{\circ}C$ for 30 minutes, has the highest adsorption capacity. in this work, the two kinds of pellet-type adsorbents (bead-type, crushed-type) were prepared. The crushed-type adsorbent was found to show a better adsorption/desorption performance than the bead-type adsorbent. The crushed-type adsorbent showed a good adsorption capacity of $Pb^{2+}$ like the powder-type adsorbent.

• Applied Chemistry for Engineering
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• v.24 no.5
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• pp.551-557
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• 2013

In the present study, pristine carbon nanotube (p-CNT) and thiolated carbon naotube (t-CNT) electrodes were investigated to improve their detectabilities for cadmium (Cd) and lead (Pb). In addition, we evaluate which reaction mechanism is used when the electrolyte contains both Cd and Pb metals. Square wave stripping was employed for analyzing the sensitivity for the metals. A frequency of 30 Hz, a deposition potential of -1.2 V vs. Ag/AgCl and a deposition time of 300 s were used as optimal SWSV parameters. t-CNT electrodes show the better sensitivity for both Cd and Pb metals than that of p-CNT electrodes. In case of Cd, sensitivities of p-CNT and t-CNT electrodes were $3.1{\mu}A/{\mu}M$ and $4.6{\mu}A/{\mu}M$, respectively, while the sensitivities for Pb were $6.5{\mu}A/{\mu}M$ (p-CNT) and $9.9{\mu}A/{\mu}M$ (t-CNT), respectively. The better sensitivity of p-CNT electrodes is due to the enhancement in the reaction rate of metal ions that are facilitated by thiol groups attached on the surface of CNT. When sensitivity was measured for the detection of Cd and Pb metals present simultaneously in the electrolyte, Pb indicates better sensitivity than Cd irrespective of electrode types. It is ascribed to the low standard electrode potential of Pb, which then promotes the possibility of oxidation reaction of the Pb metal ions. In turn, the Pb metal ions are deposited on the electrode surface faster than that of Cd metal ions and cover the electrode surface during deposition step, and thus Pb metals that cover the large portion of the surface are more easily stripped than that of Cd metals during stripping step.

• Korean Journal of Heritage: History & Science
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• v.57 no.1
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• pp.146-159
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• 2024

In this study, a study on the production technology of the Buddha statue and the production of raw material origin was conducted through scientific analysis on the Bronze seated Bodhisattva Statue of Goseongsa Temple, a treasure. As a result of microstructure analysis through a metal microscope, it was confirmed that the microstructure of the Bronze seated Bodhisattva Statue of Goseongsa Temple was a process-type dendritic structure, and the casting structure of bronze was well represented, so it was manufactured through casting. Subsequently, as a result of analyzing the alloy composition ratio through SEM-EDS, it was identified as a ternary alloy with 81.26 wt% of copper (Cu) and 16.42 wt% of tin (Sn) and 1.72 wt% of lead (Pb). The results of the analysis of lead isotope ratios using a thermal ionization mass spectrometer (TIMS) were substituted into the distribution of lead isotope ratios on the Korean Peninsula, it was shown in corresponding to Jeolla-do and Chungcheong-do regions and North and South Gyeongsang Province. This suggests that the raw materials used in their production were likely sourced from the mines around Goseong Temple in Gangjin. Despite the fact that the statue is a medium and large Buddha with a total height of 51 centimeters, 1.72 wt% of lead (Pb) was found as a result of alloy composition ratio analysis, which showed a similar composition to the lead content ratio of small bronze and gilt-bronze Buddha statues. Therefore, we compared and analyzed the results of the analysis of the composition ratio of the alloys of bronze and gilt bronze statues, which has been scientifically analyzed with a compositional age similar to that of the Bronze seated Bodhisattva Statue of Goseongsa Temple. Comparison results, Various factors, such as the size of the Buddha statue as well as its stylistic characteristics and the age of composition, may exist in determining the alloy composition ratio of the bronze and gilt bronze Buddha statues, and it was confirmed that the alloy composition ratio or casting technology was properly adjusted when the Buddha statue was created. In other words, it is judged that a more comprehensive system of Buddha statue production technology should be investigated by conducting archaeological and art history studies on stylistic characteristics and age of composition, as well as scientific analysis results such as observation of internal structure, microstructure observation, and analysis of alloy composition ratio using radiation transmission irradiation.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.1
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• pp.3-10
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• 2016

Effects of acid ($HNO_3$ and HCl) modification on the adsorption properties of Pb(II) and Cu(II) onto bamboo-based activated carbon (BAC) were investigated through a series of batch experiments. The carbon content increased and oxygen content decreased with acid treatment. $HNO_3$ induced carboxylic acids and hydroxyl functional groups while HCl added no functional group onto BAC. The pseudo-second order model better described the kinetics of Pb(II) and Cu(II) adsorption onto experimented adsorbents, indicating that the rate-limiting step of the heavy metal sorption is chemical sorption involving valency forces through sharing or exchange of electrons between the adsorbate and the adsorbent. The equilibrium sorption data followed both Langmuir and Freundlich isotherm models. The adsorption capacities of BAC were affected by the surface functional groups added by acid modification. The adsorption capacities were enhanced up to 36.0% and 27.3% for Pb(II) and Cu(II), respectively by the $HNO_3$ modification, however, negligibly affected by HCl.

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.441-448
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• 2016

Heavy metal removal study is conducted from synthetic waste water by reduction and oxidation(redox) reaction of Cu-Zn metal alloy and adsorption reaction of aluminium silicate. Heavy metal whose ionization tendency is smaller than zinc are reducted in an aqueous solution, and the concentration of ionized zinc is reduced by adsorption reaction. The average diameter of metal alloy micro fiber is about $200{\mu}m$, and the surface area is wide enough to get equilibrium in a single cycle treatment. A single cycle treatment of redox reaction of Cu-Zn metal alloy, could remove 100.0 % of Cr(III), 98.0 % of Hg, 92.0 % of Sn and 91.4 % of Cu respectively. An ionization tendency of chromium is very close to zinc, but removal efficiency of chromium by redox reaction is significant. This result shows that trivalent chromium ion is expected to generate hydroxide precipitation with $OH^-$ ion generated by redox reaction. Zinc ion generated by redox reaction is readily removed by adsorption reaction of aluminium silicate in a single cycle treatment. Other heavy metal components which are not perfectly removed by redox reaction also showed very high removal efficiency of 98.0 % or more by adsorption reaction. Aluminium ion is not increased by adsorption reaction of aluminium silicate. That means heavy metal ion removal mechanism by adsorption reaction is turned out to be not an ion exchange reaction, but an adsorption reaction.

• Analytical Science and Technology
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• v.24 no.4
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• pp.275-281
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• 2011

$AlPO_4$-type material was synthesized by a reaction of $Al(OH)_3$ and H3PO4 with organic templates from wastewater of detergent manufacturer. The surface of material was coated with carboxylate groups by the reaction of succinic anhydride with surface amino groups which were formed by treatment of the material with APTMS. Powder XRD patterns showed the characteristic patterns of $AlPO_4$. Morphology of the material was examined using a SEM and the functional groups were investigated by FT-IR analysis. The surface charge of a aqueous suspension was analyzed: $AlPO_4-NH_2$ has positively charged surface while $AlPO_4$-COOH has negatively charged one. They were used for the removal of toxic metals from aqueous solution. The lead ions were adsorbed on the surface by the formation of complexes with carboxylate of surface and $K_d$ was 91.1 mL/g. In conclusion, the $AlPO_4$-COOH might be applicable in the removal of toxic metal ions from aqueous system.

• Korean Journal of Environment and Ecology
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• v.22 no.3
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• pp.260-267
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• 2008

This study was carried out to investigated the relation between air depositions and soil properties in Gyeongsanman province. Soil pH was average 4.40 in regions, and was the highest soil pH value in Miryang-sanne(pH 5.02), the lowest pH value in Namhae-seomyeon(pH4.08). Soil pH, soil organic matter content, avail phosphorus, K, Ca and cation exchange capacity(CEC) were significantly different among regions(p<0.05). Pb in Heavy metal content was 3.86mg/kg average value, and was the highest in Keo-je region(9.87mg/kg), the lowest in Mryang-sanne (0.86mg/kg). Zn, Cd, Cr and Ni were significantly different among regions(p<0.05). Correlation between rainfall pH and soil properties were positive in soil $pH(r=0.7826^{**})$, Ca$(r=0.6278^*)$, Mg$(r=0.5841^*)$, CEC$(r=0.6341^{**})$ and Cd$(r=0.5995^*)$, and were negative in Pb$(r=-0.5283^*)$. Correlation between $SO_2$ concentration and soil properties was negative in soil pH$(r=-0.6796^{**})$, Ca$(r=-0.5810^*)$, Mg$(r=-0.5522^*)$) and CEC$(r=-0.5905^*)$. Correlation between $NO_2$ concentration and soil properties were positive in organic matter $(r=0.6208^*)$, K$(r=0.5380^*)$. It was predicted that rainfall and $SO_2$ concentration would affect soil acidification, and soil heavy metal content related Cd and Pb. Others soil heavy metal were not related.

• Clean Technology
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• v.12 no.3
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• pp.171-174
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• 2006

The adsorbent for removal of heavy metal ions is prepared reutilizing the leached sludge generated in process of making the red mud coagulant we have develope. The pellet-type adsorbent is made by heat-treating a mixture of 10g of the leached sludge, 1g of kaolin, and 2 g of sodium silicate solution at $600^{\circ}C$ for 2 hours. In experiments of batch adsorption, the adsorbent shows good performance in adsorption of $Pb^{2+}$ ion.

• Journal of the Korean Chemical Society
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• v.60 no.6
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• pp.402-409
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• 2016

Thin films of lead sulfide colloidal quantum dots (CQDs) of 2.8 nm in diameter are fabricated and their surfaces are passivated by 3-mercaptopropionic acid (MPA) ligand or hybrid type ($MPA+CdCl_2$) ligand, respectively. The changes in valence band electronic structure and atomic composition of each PbS CQD film upon post-treatment such as air, N2 annealing or UV/Ozone have been studied by photoelectron spectroscopy. The air annealing makes the CQD fermi level to move toward the valence band leading to "p-type doping" regardless of ligand type. The UV/Ozone post-treatment generates $Pb(OH)_2$, $PbSO_x$ and PbO on both CQD surfaces. But the amount of the PbO has been reduced in hybrid type ligand case, especially. That is probably because the extra Pb cations in (111) surface are additionally passivated by $Cl_2$ ligand, which limits the reaction between the Pb cation and ozone.