• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.158-159
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• 2005

This study showed that the highest temperature point of the Dongrae thermal spring in Pusan was moved to the north direction of the Dongrae fault as times goes by. The Br concentration(1.5mg/L) in Dongrae thermal waters indicated the influence of 2% seawater mixing. If the simple mixing without hydrochemical reaction occurs between seawater and thermal water, the concentration of Mg will be about 20mg/L. But the low concentration(0.1 mg/L) of Mg, contrary to high concentration(10 mg/L) of surrounding groundwater not affected by thermal water, suggested the thermal water, seawater and rock interactions. The calculation of saturation index(SI) by using the geochemical code of EQ3NR showed that the Mg in thermal groundwater, which was introduced by seawater, was removed by the precipitation of Antigorite (SI: log Q/K =71.753, $Mg_{48}Si_{24}O_{85}(OH)_{62}$) and Tremolite (SI: 8.463, $Ca_2Mg_5Si_8O_{22}(OH)_2$), Talc (SI: 6.409, $Mg_3Si_4O_{10}(OH)_2$), Dolomite (SI: 2.014, $CaMg(CO_3)_2$), Chrysotile (SI: 3.698, $Mg_3Si_2O_5(OH)_4$) in the crack of fault zone. The highest temperature point in the study area will move to north direction and stop in the Jangjun area without the input of seawater.

• Microbiology and Biotechnology Letters
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• v.38 no.2
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• pp.216-221
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• 2010

This study shows an application of microbiologically induced carbonate precipitate for strength improvement and crack remediation of cement-sand mortar. Seven calcium carbonate-forming bacteria (CFB) were isolated from Dok-do and partially identified by DNA sequence analysis of the 16s rRNA gene. Crystal aggregates were apparent around the bacterial colonies grown on an agar medium. These strains showed strain specific $CaCO_3$ precipitation on urea-$CaCl_2$ medium. Among 7 isolates, Arthrobacter nicotinovorans KNUC601, Microbacterium resistens KNUC602, Agrobacterium tumefaciens KNUC603, Exiguobacterium acetylicum KNUC604, and Bacillus thuringiensis KNUC606 showed a repairing of artificial forced cracks in cement-sand mortar. Compressive strength of cement-sand mortar consolidated with Stenotrophomonas maltophilia KNUC605 was increased around 14.07% compared with that of negative control.

• Journal of the Korea Concrete Institute
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• v.21 no.4
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• pp.501-511
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• 2009

This study was conducted to develop self-healing ability of concrete so that inspection could be available even in the event of minute cracks without complex works at any time for more economic concrete structure maintenance and longevity. A completely different method has been carried out in comparison with many of similar researches on self-healing concrete. This is a basic study on the development of self-healing concrete using microbial biomineralization. Compounds were generated except for cells by precipitation reaction of CaC$O_3$ during the microbial metabolism and we examined the use as a binder that hardens the surface of sand using biomineralization that Sporosarcina pasteurii precipitates CaC$O_3$. In result, the formation of new mineral and hardening of sand surface could be verified partly, and it was available for cracks to be repaired by calcite with organic (microorganism) and inorganic (CaC$O_3$) complex structure through the basic experiment a little bit. Therefore the use of biomineralization by this sort of microbial metabolism for concrete structure helps to develop absolute repair-concrete like this concrete with microorganism. The effect of microbial application will be one of the most important research tasks having influence on not only repair for concrete structure but also development of new materials able to reduce environmental problems.

• BMB Reports
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• v.37 no.3
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• pp.275-281
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• 2004

Rhodanese was isolated and purified from the cytosolic fraction of liver tissue homogenate of the fruit bat, Eidolon helvum, by using ammonium sulphate precipitation and CM-Sephadex C-50 ion exchange chromatography. The specific activity was increased 130-fold with a 53% recovery. The $K_m$ values for KCN and $Na_2S_2O_3$ as substrates were $13.5{\pm}2.2\;mM$ and $19.5{\pm}0.7\;mM$, respectively. The apparent molecular weight was estimated by gel filtration on a Sephadex G-100 column to be 36,000 Da. The optimal activity was found at a high pH (pH 9.0) and the temperature optimum was $35^{\circ}C$. An Arrhenius plot of the heat stability data consisted of two linear segments with a break occurring at $35^{\circ}C$. The apparent activation energy values from these slopes were 11.5 kcal/mol and 76.6 kcal/mol. Inhibition studies on the enzyme with a number of cations showed that $Mg^{2+}$, $Mn^{2+}$, $Ca^{2+}$, and $Co^{2+}$ did not affect the activity of the enzyme, but $Hg^{2+}$ and $Ba^{2+}$ inhibited the enzyme.

• Journal of Soil and Groundwater Environment
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• v.20 no.3
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• pp.83-91
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• 2015

Mine soil contamination by high levels of metal ions that prevents the successful vegetation poses a serious problem. In the study presented here, we used the microbial biocatalyst of urease producing bacterium Sporosarcina pasteurii or plant extract based BioNeutro-GEM (BNG) agent. The ability of the biocatalysts to bioremediate contaminated soil from abandoned mine was examined by solid-state composting vegetation under field conditions. Treatment of mine soil with the 2 biocatalysts for 5 months resulted in pH increase and electric conductivity reduction compared to untreated control. Further analyses revealed that the microbial catalysts also promoted the root and shoot growth to the untreated control during the vegetation treatments. After the Sporosarcina pasteurii or plant extract based BNG treatment, the microbial community change was monitored by culture-independent pyrosequencing. These results demonstrate that the microbial biocatalysts could potentially be used in the soil bioremediation from mine-impacted area.

• Advances in concrete construction
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• v.15 no.3
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• pp.149-159
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• 2023

Water glass (WG) and sodium sulfate (SS) were used to prepare polymeric aluminum chloride residue cement mortar (PACRM) by single and compound blending with polymeric aluminum chloride waste residue, respectively. The structural strength and textural characteristics examinations showed that PACRM consistency increased by incorporating WG, but decreased by incorporating SS. When WG and SS were compounded, the mortar consistency initially rose before falling. The compressive strength of PACRM increased and then decreased as WG was increased. The mechanical properties of PACRM were better enhanced by SS than WG, showing no strength deterioration. The main reason for the improved mechanical properties of polymeric aluminum chloride waste residue in the presence of activators is the increased precipitation of reactive substances, such as C-S-H gels, calcium silica, and Ca(OH)₂. The density of the specimens with PACRM and the degree of aggregation of hydration products were significantly enhanced by generating more hydration products in the mortar. Further, the cracks and pores were significantly reduced, and the matrix structure was continuous and dense at 5% SS doping and 3% compound doping.

• Economic and Environmental Geology
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• v.32 no.6
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• pp.611-631
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• 1999

Enviromental geochemisty and heary metal contamination at the Kongjueil mine creek were underaken on the basis of physicohemical properties and mineralogy for various kinds of water (surface, mine and ground water),soil, precipitate and sediment collected of April and December in 1998. Hydrgeochemical composition of the water samples are characterized by relatively significant enricant of Ca+Na, alkiali ions $NO_3$ and Cl inground and surfore water, wheras the mine waters are relatively eneripheral water of the mining creek have the characteristics of the (Ca+Mg)-$(HCO_3+SO_4)$type. The pH of the mine water is high acidity (3.24)and high EC (613$\mu$S/cm)compared with those of surface and ground water. The range of $\delta$D and $\delta^{18}O$ values (relative to SMOW) in the waters are shpwn in -50.2 to -61.6% and -7.0 to -8.6$\textperthousand$(d value=5.8 to 8.7). Using computer program, saturation index of albite, calcite, dolomite in mine water are nearly saturated. The gibbiste, kaolinite and smectite are superaturated in the surface and ground water, respectively. Calculated water-mineral reaction and stabilities suggest that weathing of silicate minerals may be stable kaolinite owing to the continuous water-rock reaction. Geochemical modeling showed that mostly toxic heavy metals may exist larfely in the from of metal-sulfate $(MSO_4\;^2)$and free metal $(M^{2+})$ in nmine water. These metals in the ground and surface water could be formed of $CO_3$ and OH complex ions. The average enrichment indices of water samples are 2.72 of the groundwater, 2.26 of the surface water and 14.15 of the acid mine water, normalizing by surface water composition at the non-mining creek, repectively. Characteristics of some major, minor and rate earth elements (Al/Na, K/Na, V/Ni, Cr/V, Ni/Co, La/Ce, Th/Yb, $La_N/Yb_N$, Co/Th, La/Sc and Sc/Th) in soil and sediment are revealed a narrow range and homogeneous compositions may be explained by acidic to intermediate igneous rocks. And these suggested that sediment source of host granitic gneiss colud be due to rocks of high grade metamorphism originated by sedimentary rocks. Maximum concentrations of environmentally toxic elements in sediment and soil are Fe=53.80 wt.% As=660, Cd=4, Cr=175, Cu=158, Mn=1010, Pb=2933, Sb=4 and Zn=3740 ppm, and extremely high concentrations are found are found in the subsurface soil near the ore dump and precipitates. Normalizing by composition of host granitic gneiss, the average enerichment indices are 3.72 of the sediments, 3.48 of the soils, 10.40 of the precipitates of acid mine drainage and 6.25 of the soils near the main adit. The level of enerichment was very severe in mining drainage sediments, while it was not so great in the soils. mineral composition of soil and sediment near the mining area were partly variable being composed of quartz, mica, feldspar, chlorite, vermiculite, bethierin and clay minerals. reddish variable being composed of quartz, mica, feldspar, chlorite, vermiculite, bethierin and clay minerals. Reddish brown precipitation mineral in the acid mine drainage identifies by schwertmanite. From the separated mineralgy, soil and sediment are composed of some pyrite, arsenopyite, chalcopyrite, sphalerite, galena, malachite, goethite and various kinds of hydroxied minerals.

• Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.149-154
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• 1999

Response Surface Methodology was applied for optimizing the processing parameters of ultrasound treatment in order to produce low-molecular alginate. The use of ultrasound significantly reduced viscosity of alginate solutions. Suggested parameters of ultrasound treatment for maximum reduction of alginate molecular weight were: specific intensity, 115.81 $W/cm^2$ at 20kHz frequency; treatment time, 35.55 min; temperature, $20.08^{\circ}C$; alginate concentration, $2.5\%$. Low-molecular alginate obtained by ultrasound had two peaks on Sepharose CL-6B gel filtration. The viscosities of control, fraction I, and fraction II at $0.1\%$ concentration and $25^{\circ}C$ were 3.07, 1.23, and 0.82cps, respectively. Molecular weights of control, fraction I, and fraction II alginates were 336,500, 70,400, and 52,800 daltons, and their solubilities were 3, 6, and $14\%$, respectively. The lower molecular weight of alginate, the lower the alcohol precipitation and the higher $Ca^{2+}$ ion binding capacities. Heavy metal ion binding capacities of alginates were high in the following order of Pb, Cd, Zn, and Co.

• Clean Technology
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• v.17 no.2
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• pp.166-174
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• 2011

The xAl-yCe oxide catalysts with different mol ratios of Al/(Al+Ce) were prepared by a co-precipitation method and Pt supported on xAl-yCe oxide catalysts were synthesized by an incipient wetness impregnation method. The catalysts were characterized by X-ray Diffraction (XRD), $N_2$ sorption, and $H_2$/CO-temperature programmed reduction ($H_2$/CO-TPR) to correlate with catalytic activities in co oxidation. Among the catalysts studied here, Pt/1Al-9Ce oxide catalyst showed the highest activity in dry and wet reaction conditions and the catalytic activity showed a typical volcano-shape curve with respect to Al/(Al+Ce) mol ratio. When the presence of 5% water vapor in the feed, the temperature of $T_{50%}$ was shifted ca. $30^{\circ}C$ to lower temperature region than that in dry condition. From CO-TPR, the desorption peak of $CO_2$ on Pt/1Al-9Ce oxide catalyst showed the highest value and well correlated the catalytic performance. It indicates that the Pt/1Al-9Ce oxide catalyst has a large amount of active sites which can be adsorbed by co and easy to supplies the needed oxygen. In addition, the amount of pentacoordinated $Al^{3+}$ sites obtained through $^{27}Al$ NMR analysis is well correlated the catalytic performance.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.4
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• pp.403-415
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• 1999

To properly assess air pollution levels, application of quality assurance and quality control(QA/QC) is believed to be an essential step. In order to cope with such scientific principle, a field study was designed with an aim of comparing: 1) the methods of calibration for airborne pollutants and 2) the protocols developed for their measurements. Measurements were made at Han Yang University, Seoul during 29 May through 1 June 1998 under the management of the Division of Measurements and Analysis(DMA) of Korean Society for Atmospheric Environment(KOSAE). In this work, we report our results of intercomparative measurements on several gaseous criteria pollutants that were investigated mainly by the two institutes-Seoul National University(SNU) and the Korean Research Institute for Standards and Science(KRISS). Although measurements of major gaseous pollutants had been made routinely by many scientific institutes and organizations in Korea, most scientists involved in those studieswere obliged to do their experiments on the basis of their own procedural steps spaning from the preparation of gaseous standards to the methodological selections for the calibration. Hence, this campaign offered a unique opportunity to examine many important aspects on the measurements of these important gaseous pollutants. In the course of our study, we investigated the compatibility of data sets obtained by the two institutes in concert with reference data sets collected concurrently from a government-managed monitoring station. On the basis of our study, we conclude that different data sets made by different participants during this campaign agree well within the reasonable range of uncertainties.low, which indicated that during this period the potential acidity of precipitation was high but the neutralizing capacity was low. For Spring, pAi was very low but pH was slightly high. This was likely due to the large amount of $CaCO_3$ in the soil particles transported over a long range from the Chinese continent that were incorporated into the precipitation, and then neutralized the acidifying species with its high concentraton.