• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.399-406
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• 2004

본 연구에서는 국내 원전이 위치한 지역의 토양에서 $Cs^{137}$의 축적 경향을 파악하기 위하여 원전이 위치한 영광군 관내의 평지와 고산지대인 금정산, 불갑산 및 영광원전으로부터 원거리에 위치한 내장산 등을 대상으로 토양 중 $Cs^{137}$의 화학적인 특성과 고도에 따른 $Cs^{137}$의 축적 경향을 평가하기 위하여 실험을 통한 연구를 수행하였다. 일반적으로 국내 토양 중 $Cs^{137}$의 농도는 불검출 - 2523q/kg-dry의 범위 내에 포함되었으며 본 연구에서 수행한 평지부분과 고산지대인 원전으로부터 2km 떨어진 금정산, 약 20km 떨어진 불갑산 및 원거리에 위치한 내장산에서도 지금까지의 $Cs^{137}$ 농도 범위에 들었다. 그러나 고산지대는 평지에서와는 다르게 고도가 증가함에 따라 $Cs^{137}$ 농도도 증가하는 경향을 보이고 있고, 정상 부분보다 $Cs^{137}$의 농도가 하부 부분보다 더 높게 나타났고 영광원전 인근 일반평지부분보다는 $Cs^{137}$의 방사능 농도가 2~6배 정도의 높은 경향을 나타내었다. 연구결과 $Cs^{137}$의 분포는 지형적 요인(고도, 강수량 등)과 토양의 화학적 요인(양이온치환용량)과 상관성이 근 것으로 나타났다. 지형적 요인으로는 주로 고도를 들수가 있는데 높은 고도의 산의 경우 대기중 $Cs^{137}$이 토양에 침투되는 기회가 커짐으로 동일한 토질 조건의 평지 토양에 비해 높은 $Cs^{137}$ 준위를 나타내었다. 토양의 화학적 요인으로는 양이온치환용량이 주요 인자임이 규명되었다. 양이온치환용량은 침적된 $Cs^{137}$을 토양에 고정시키는 능력을 나타내며 같은 지형조건에서 높은 양이온치환용량을 가진 시료가 낮은 양이온치환용량을 가진 토양에 비해 $Cs^{137}$ 농도가 높은 값을 보였다.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2005.12a
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• pp.55-64
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• 2005

1. 지렁이 분립량이 증가할수록 용적비중(bulk density), 유효수분함량(available water content), pH, 전기전도도(electrolytic conductivity), 무기물(ash), 전질소(total nitrogen), 양이온치환능력(cation exchange capcaity), 유효인산(available $P_{2}O_{5}$), 치환성양이온(exchangeable cation)이 증가하였다. 2. 근대는 분립 40${\sim}$100%의 혼합비율에서 초장(PL), 엽면적(LA), 엽수(NL), 엽면적(LA), 지상부 건물중(SHW), 근중(RW), 줄기두께(SD), 근중(RW) 및 생물학적수량(BY)이 다른 처리구보다 유의하게 높았다. 3. 열무는 분립 40${\sim}$60%의 혼합비율에서 초장(PL), 지상부 건물중(SHW), 근중(RW), 생물학적수량(BY)이 다른 처리구보다 유의하게 높았다. 3. 시금치와 상추는 40%의 혼합비율에서 지상부중(SHW), 근중(RW), 생물학적수량(BY)이 다른 처리구에 비해 유의하게 높았다(p${\leq}$0.05).

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.6
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• pp.371-377
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• 2004

Sulfate adsorption in forest soils is a process of sulfur dynamics playing an important role in plant uptake, cation movement, acid neutralization capacity and so on. The relationship between sulfate adsorption and some physicochemical properties of four forest soils was investigated. Extractable sulfate contents and sulfate adsorption capacity (SAC) in the forest soils varied much among study sites. Extractable sulfate contents were more in sub-surface soils with lower organic matter and greater Al and Fe oxides than in surface soils. The average contents of $Al_d$ and $Fe_d$ in the sub-surface soils were 8.49 and $12.45g\;kg^{-1}$, respectively. Soil pH, cation exchange capacity and clay content were positively correlated with the extractable sulfate contents and SAC. Organic carbon content, however, was negatively correlated with the extractable sulfate contents, implying the competitive adsorption of sulfate with soil organic matter. Considerably significant correlation was found between inorganic + amorphous Al and Fe oxides and the sulfate adsorption, but crystalline Al and other fractions of Fe oxide showed no correlation. Relatively close relationship between the adsorbed sulfates and soil pH, cation exchange capacity, or amorphous Al oxides indicates that the accelerated soil acidification may substantially reduce the potential for sulfate adsorption contributing to sulfur flux in forest ecosystems.

• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.14-20
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• 2007

In order to examine the differences in antioxidant enzyme activities which represent defence mechanism to stressful environments, and soil properties between healthy and declining (or unhealthy) trees, we selected three sites, Witseorum, Youngsil and Sungpanak (Jindallebat). Antioxidant enzymes including Ascorbate peroxidase (APX) and Glutathione Reductase (GR), forest soil properties including soil texture, soil pH, organic matter, total nitrogen, available phosphate, cation exchange capacity, exchangeable cation content and nutrient contents in leaves of Abies koreana (Korean fir) trees were analyzed. There were no significant differences between healthy and declining trees in GR activity. However, seasonal difference in antioxidant enzyme activity was observed. GR activity was lower in June and August than that of September. Soil chemical and physical properties of each site showed a tendency that organic content, total nitrogen content, available phosphorus, cation exchange capacity and cation content were lower at the site of declining trees than the site of healthy trees.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.1
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• pp.143-148
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• 2007

The objective of this study was to investigate the proper conditions of calcination and calcium extraction from powdered oyster shell. The physical characteristics such as particle size distribution, surface morphology, and thermal gravity were examined. The following result were obtained. As the powdered oyster shell was ignited in high temperature of $650^{\circ}C$ to $950^{\circ}C$, the calcination reactions was effectively progressed. The amount of weight loss during calcination would be matched with the generation of carbon dioxide gas. In the calcination of powdered oyster shell, the amount of weight loss increased according to the increased of calcination temperature and the decrease of mean particle size. It was founded that the proper temperature and retention time of calcination was $850^{\circ}C$ and 40 minute. In the extraction of calcium into liquid form using acid addition, the calcination oyster shell was more effective than the non-calcinated shell. The liquid calcium extraction technique using the calcinated oyster shell needed more researches considering cost evaluation.

• Polymer(Korea)
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• v.37 no.4
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• pp.533-538
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• 2013

Sodium chloride is present in our body fluids, and the blood contains approximately 0.9 wt% salt, which plays an important role in maintaining the osmotic pressure. However, the amount of salt intake has consistently increased, and an excessive intake can be the cause of high blood pressure, etc. In this study, it was investigated in vivo and in vitro whether biocompatible ionic polymers with K or Ca ions can be replaced by Na ions through an ion exchange process to be excreted. Among the polymers, Ca-polystyrene sulfonate, K-polystyrene sulfonate, Ca-carrageenan, and Ca-tamarind had an excellent Na exchange ability in the body temperature, simulated gastric fluid and also simulated intestinal fluid. The mechanism of Na removal by absorption and excretion without changing food taste in the mouth through the insolubility properties of these polymers is expected to be a solution for the current problems related with excess sodium intake.

• Journal of Animal Environmental Science
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• v.18 no.2
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• pp.63-74
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• 2012

This experiment was carried out to investigate the effect of different stocking rate on growth, cast production and conversion efficiency of organic matter to tissues of earthworm. The carbon and nitrogen ratio (C/N) of tested Korean cow manure was 25.1, it was estimated an adequate ratio as feed for earthworms. The different stocking rates were 1:8(S-1), 1:16(S-2), 1:32(S-3) 1:64(S-4) 1:128(S-5) and 1:256 (S-6) as the ratios of earthworm fresh weight to biomass of Korean cow manure, respectively. A stocking rate of 1:32(S-3) was obtained a significantly highest values of increasing rate and conversion efficiency of organic matter to earthworm tissues. The mean values of increasin g rate of fresh weight and conversion efficiency of organic matter to earthworm tissues were 10.63 mg/day and 6.65% at the ratio of 1:32(S-3) with a rearing volume was $56.6cm^3$. A stocking rate of 1:8(S-1) was obtained a highest ratio of vermicasts, but showed a negative values of increasing rate and conversion efficiency of organic matter to earthworm tissues, it may due to severely food competition between individuals during the rearing periods. The pH, total nitrogen, available phosphorus, cation exchange capacity and exchangeable cations of vermicasts tended to increase with stocking rate. Especially, available phosphorus, cation exchange capacity and exchangeable cations of vermicasts tended to increase with rearing progressed. Vermicasts have the potential for improving plant growth when amended to container medium and soil according to increased availability of nutrients and improved physicochemical properties.

• Korean Journal of Materials Research
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• v.11 no.2
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• pp.120-125
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• 2001

Generally, hydroxyapatite(HAp), zeolite, carbon molecular sieve , activated carbon and alumina are used as heavy metal ions adsorption materials. Among those adsorption materials, HAp which has good positive ion-exchange ability with metal ion, and zeolite are utilized in wastewater treatment. Most of water pollutions are caused by hazardous heavy metals ions as well as bacteria in waste water. In this study, a adsorption materials (HAP and zeolite) are ion-exchanged with a well known antimicrobial metal ions, such as $Ag^+,\;Cu^{2+},\;and\;Zn^{2+}$, in order to give a adsorption of heavy metal ions and a killing effects of bacteria. The antimicrobial effects of adsorption materials are observed using by E. Coli. The results show that there is a complete antimicrobial effect in the adsorption materials with $Ag^+$ at the concentration of $1{\times}10^{-4}$cell/$m\ell$ of E. Coli until 24 hours. However, there is not good antimicrobial effects in the adsorption materials with $Cu^{2+},\;and\;Zn^{2+}$ substitution. Feng et. al. showed the denaturation effects of silver ions which induces the condensed DNA molecules and losing their replication abilities.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.188-193
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• 1998

Soil pH change is an important factor which determines soil chemical properties. It is an indicator of the effect of urban environmental pollution on soils and plant growth. The objective of this study was to assess the effect of air pollution on the soil of Seoul urban forests during the course of the air pollution being dipersed toward suburb area. Study sites were divided into four sections of concentric circles with 5km interval. Soil samples were collected from A and B horizons in the urban forests, and analyzed for soil pH, soil buffer capacity, cation exchange capacity, and base saturation. Soil pH ranged from 3.96 to 5.08 for A horizon and from 4.10 to 5.25 for B horizon, which were not significantly different among the sections. However, there was a trend of soil pH lowered at the sections close to the urban center. Soil buffer capacity was lower at 0-5km and 5-10km sections compared to that at the outer sections. Cation exchange capacity and base saturation were not different significantly among the sections. Following the pattern of air pollutants being dispersed from urban center to suburb, soil acidification was observed at the urban forests in Seoul area. Low level of soil buffer capacity toward the urban center was an indicator of soil acidification at the urban forests.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.4
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• pp.271-278
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• 2004

This paper shows our experiment is performed to understand the exposure tendency of $^{137}Cs$ according to the height of area and also, to supplement it by considering chemical characters of $^{137}Cs$ exposed to the soil. The samples we use for this experiment are from the general flat area of Yeonggwang county where it has NPPs, the high places of Keumjung & Bulgap mountains, and Naejan mountain where it is quite far from the NPPs. The data from this experiment show that the exposure of $^{137}Cs$ is not harmful since its range is around 252 Bq/kg-dry in most of sampled soils such as from the general flat area, the high place of Keumjung mountain where is 2 km away from the NPPs, the other high place of Bulgap mountain where is about 20 km away from the NPPs, and Naejan mountain where it is far from the NPPs. Not like the general flat area, however, the data show that the higher the area is the more $^{137}Cs$ is exposed. That is, at the top of mountains, the more $^{137}Cs$ is exposed compared to at the bottom area. It is almost $2{\~}6$ times more than the general flat area of Yeonggwang county where it has NPPs. The data also show that the spread of $^{137}Cs$ is deeply related to the geographical(the height of area, rainfall, etc..) factors and chemical factors of soils. As the geographical factors, there are far more chances to be exposed of $^{137}Cs$ at the high area of mountains through the air compared to at lower area and therefore, we can get more high-leveled readings of $^{137}Cs$ at the high area while it is low-leveled ones at the general flat area even if both of them have the same soil conditions. Regarding the chemical factors of soil, it is clarified that the CEC is the key factor. The CEC means the capability of sticking $^{137}Cs$ accumulated into the soil. Hence, the more CEC it has the more high-leveled readings of $^{137}Cs$ we get under the same geographical condition.