• Journal of Korea Soil Environment Society
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• v.2 no.1
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• pp.45-50
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• 1997

The change of industrial structure has brought the sharp declination of mine products, and has made many mines closed, which results in environmental pollution by untreated acid mine drainage(AMD). AMD with low pH and high concentration of heavy metals could severely destroy the ecosystem. Many researches have been carried out for the treatment of AMD. In this study, we have treated AMD with oak compost, mushroom compost, sludge cake and cow manure which usually used in AMD treatment systems, and compared the capability of each organic matter. Cow manure and oak compost have been most effective among 4 organic materials. Oak compost removed the heavy metals by ion exchange between Ca-rich particles and soluble heavy metal ions. It also captured the heavy metals using bound functional groups like -OH and -COO-. Sulfate reducing bacteria existing in the cow manure removed effectively heavy metals by producing metal sulfide compound. Therefore, it is effective to use both organic materials in mixture on the treatment of AMD.

• The Korean Journal of Mycology
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• v.20 no.3
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• pp.259-268
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• 1992

Fifty-three actinomycetes antagonistic to Phytophthora capsici and Magnaporthe grisea were isolated from rhizosphere soils in six pepper-growing areas and ashore soils. Thirty-two antagonistic actinomycetes, showing inhibition zone larger than 5 mm, were classified into 20 groups according to their colony morphology and color. The antagonistic activity against P. capsici greatly varied, which showed inhibition zone sizes in the ranges from 5.7 to 17.5 mm on V-8 juice agar and from 2.5 to 17 mm on tryptic soy agar. The antagonistic activity of some actinomycetes tested was remarkably different between the two test media. The antagonists showed a relatively broad antifungal spectrum, but their antibacterial activity was negligible, except for Pseudomonas solanacearum. Butanol extracts of culture filtrates from antagonistic actinomycetes inhibited mycelial growth of P. capsici and M. grisea, thereby confirming strongly antibiotic production in culture. Culture filtrates of some antagonistic actinomycetes completely inhibited Phytophthora blight in pepper plants.

• Korean journal of applied entomology
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• v.16 no.3 s.32
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• pp.149-154
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• 1977

Effect of Simazine(2-chloro-4,6-bis (ethylamino)-s-triazine), Nitrofen (2, 4-dichloro-4' -nitrodi­phenylether), Propanil (:3, 4-dichloropropionanilide), and Butachlor (2-chloro-2, 6-diethyl N-(buthoxy­menthyl) acetanilide on urea hydrolysis and subsequent nitrification was investigated in an upland soil incubated at $20\pm1^{\circ}C$. 1. All the herbicides tested had no effect on the hydrolysis of urea to ammonia at the recommended rates. Butachlor, at ten and fifty times the recommended rate, and Nitrofen, at fifty times the recommeded rate, depressed urea hydrolysis, resulting in reduction of ammonia. But the depressive effects were temporary, disappearing soon. Simazine and Propanil had no detrimental effect on urea decomposition at all the treated rates. 2. Also, all the chemicals tested had no effect on the nitrification process at the recommended rates. At higher concentrations of ten and fifty times the recommended rate Butachlor and Nitrofen inhibited the oxidation of nitrite, and propanil long inhibited the oxidation of ammonium to nitrite, but was inactive against nitrite oxidizer. These inhibitive effects of the chemicals, however, disappeared in the later period of incubation. Simazine had no effect on the nitrification process at all the treated rates. 3. The trend of change in soil pH of both the treated and untreated plots well reflected the change of soil nitrogen forms during incubation. No direct effect of the chemicals on soil pH was obserbed.

• Journal of the Korean earth science society
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• v.27 no.5
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• pp.548-556
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• 2006

The purpose of this study is to clarify the relict landform development of fluvial terrace and the soil characteristics occurring on the fluvial deposits. The physico-chemical properties of soil that are developed on terrace deposits and X-ray diffraction analysis of clay were investigated specifically. The horizon of $A_1$ consists of silt loam with reddish-brown color (5YR4/3). Its soil structures is a weak, fine, subangular, and blocky, breaking to granular. The horizon of $B_{1t}\;and\;B_{2t}$ are silt clay with either a yellowish red (5YR5/6), bright red (2.5YR4/6) color. This soil structure is weak, subangular, and blocky, with thin discontinuous bright red (2.5YR4/6) clay cutans and soft manganese concretions. This red soil structure is made on heavy-textures. It is packed compactly with parent materials of high fluvial surface sediments, and usually has a $A_1-B_{1t}-B_{2t}-C$ profile, from top to bottom. In most cases, clay accumulation in the B-horizon and clay cutans on ped surfaces are observed, which means the argillic horizon has formed. The soils derived from fluvial surface deposits are associated with soils. The soils on the high fluvial surface are considered to be a kind of paleo-red soil which were developed by strong desilicification and rubefaction, and strong leaching of bases under warmer bio-climatic condition during the old Pleistocene period. According to these morphological and anlaytical characteristics,geomorphological features and bio-climatic conditions under which the soil have developed on the high terrace sediment indicate that the soil should be classified as paleo-red soils.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.3
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• pp.289-296
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• 1985

To clarify the soil characteristics and genesis of the clayey terrace soils distributed in Yeongcheon (inland region) and Yeongil (coastal region), 9 typifying pedons including a recent local deposits were studied. The physico-chemical properties found were summarized as follows; 1. The contents of available water of the terrace soils were ranged from 12.0 to 20.3%. They were increased with increaseing clay content up to 35%, and then decreased at clay content of 35 to 55%, but were maintained about 12 to 13% when the clay content exceeds 55%. 2. The amount of water stable aggregates in the surface soils were ranged from 55.0 to 81.1%, and were low in cultivated upland where water erosion were accelerated while high in the paddy where the double cropping were practiced. The index of aggregate in cultivated upland were higher in the surface soils but the paddy soils were higher in subsoils. 3. The colloidal reactions checked by the differences between pH in $0.01N-Na_2SO_4$ and $H_2O$ indicate exchangeable acidity to exchangeable neutrality, which means a sort of Red-yellow soil forming process had been prevailed during genesis of the terrace soils. 4. Cation exchange capacity of the clayey terrace soils were averaged about 15.8-20.2me/100g of fine earth and 35.6-52.6me/100g of clay. The rates of base saturation were 32.7 to 57.6% and the rates decreased with increasing the elevations of terraces. 5. The activities of free iron oxides were 0.061 to 0.739 and the values decreased with increasing elevation while the crystallinity index of iron oxides positively correlated with elevations the values ranged from 0.067 to 0.537.

• Microbiology and Biotechnology Letters
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• v.7 no.2
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• pp.97-102
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• 1979

An actinomycete, AS-568, which produced an inhibitory substance against succinate dehydrogenase of Ehrlich ascites carcinoma and Sarcoma-180 cells of mouse, was isolated. The inhibitory activity was determined by SDI (Succinate Dehydrogenase Inhibition) method. The active substance was specific against carcinoma cells compared to normal cells in mouse; liver, kidney and brain. The inhibitory ratio was about 50％ after one hr treatment at 37$^{\circ}C$ in vitro. Maximal productivity of active substance was recognized by 5 days culture in glucose-asparagine. The active component in cultural liquid was stable in neutral pH range and heat treatment reasonably, add it was recovered from precipitate by ammonium sulfate or non-dialyrable fraction in cellophane membrane as showing the behavior of high molecular substance.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.486-486
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• 2022

미세플라스틱은 해양, 육상, 담수 및 대기환경에서 광범위하게 검출되고 있고 미세플라스틱에 대한 사람들의 우려가 커지고 있다. 담수환경에서의 미세플라스틱의 이동, 분포, 축척에 대한 연구는 해양환경에 비해 한정적으로 이루어지며, 하천은 종종 내륙에서 해양으로 미세플라스틱을 운반하는 경로로만 고려된다. 추후의 미세플라스틱의 저감정책 수립이나 이행에 있어서 미세플라스틱의 거동파악은 우선적으로 이루어져야한다. 따라서 오염의 생성에 영향을 미치는 유역의 작용을 가장 잘 표현하고, 단순히 전체의 상태를 설명하기보다는 인과관계를 밝히는 데에는 모델이 적합하다. 기후, 표면 유출, 토양이나 영양물질을 비롯한 오염물질의 부하 등을 잘 표현하고 수체 내부에서의 수질까지 동시에 시뮬레이션 가능한 기존의 잘 개발된 유역 모델의 주요 변수들은 미세플라스틱의 하천에서의 거동을 모의할 수 있다. 그 예로서 본 연구에서 HSPF의 유사(Sediment) 컴포넌트를 수정하여, 유역모델을 활용한 미세플라스틱 거동 모의 가능성을 입증하려고 한다.

• Journal of Korean Society of Forest Science
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• v.86 no.2
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• pp.186-199
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• 1997

The soils derived from granite gneiss occupy almost one third of the land area in Korea. The soils under forest vegetation, formed on granite gneiss, in Sun chon-shi, Chollanam-do in southern part of Korea, were studied to evaluate the weathering and the transformation of primary minerals into secondary minerals, clay minerals. The studied soils contained large amounts of ferromagnesian minerals, weathered biotites and were well weathered, strongly acid and low in organic matters and in ration exchange capacity. The clay contents in the Bt horizon were almost two times higher than those in the C horizon. The O horizon had a thin layer which consisted of a little decomposed plant components with a granic fabric and high porosity, and showed the micromorphological characteristics of moder humus. The related distribution pattern of the E horizon were enaulic and large amounts of silts and small amounts of sand grains were another characteristics of the E horizon. The most striking micromorphological features were multilaminated clay coating and infillings in the voids in the Bt and C horizons, and generally limpid ferriargillans ejected from the biotites and imparted red color to the soils in the Bt horizon. High clay contents in the Bt horizon was not only due to clay translocation, but also due to intensive in situ mineral weathering in this horizon. The most significant pedogenic process, revealed by the petrographic microscope and SEM, was the formation of iron oxides from biotites, the formation of tubular halloysites and the weathering models of biotites; wedge weathering and layer weathering. The thick coating on the weathering biotites showed the characteristics of the weathering process and the synthetic hematites were revealed in clays by TEM. Total chemical analysis of clays revealed extensive loss of Ca, and Na and the concentration of Fe and Al. Mineralogical studies of clays by XRD showed that micas were almost completely weathered to kaolinite, vermiculite-kaolinite intergrade, hematite, gibbsite, while halloysites from other primary minerals. Some dioctahedral mica appeared to be resistant in the soils. Parent rock of the soils contained a considerable amounts of biotites and this forest soils showed especially a dominant characteristics of biotite weathering.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.764-769
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• 2010

We investigated influence of continious application of gypsum (G: $CaSO_4{\cdot}2H_2O$), popped rice hulls (H) and zeolite (Z) on soil aggregation of reclaimed sandy loam soils. The application rates amended to fine sandy loam from reclaimed soils at Kyehwado were varied as follows:1550 (G1), 3100 (G2), 6200 (G3), 1000 (H1), 2000 (H2), 3000 (H3), and 200 (HZ1), 400 (HZ2) and 800 (HZ3) added to 1500(H) kg $10a^{-1}$, respectively. Soil aggregates were analyzed for 60, 90 and 120 days after treatments (DAT). At 60 DAT, The amount of aggregate from soil samples treated with gypsum was slightly increased with G1 while the aggregation was decreased by 4.66% for G3 for soil aggregates than thar of control. The treatments of H or HZ were effective in soil aggregation. The effect of treatment was in the order of H > HZ > G. At 90 DAT, increasing amount of gypsum attributed to decrease in soil aggregates. Therefore, we could conclude that suitable amounts of gypsum for soil aggregation in fine sandy loam might be 1550 kg $10a^{-1}$ or less. H1 increased aggregation by 7% for aggregate size between 1.0 and 2.0 mm. HZ1 was most effective in aggregation by 52.78% among the treatments while H2 and HZ3 51.50% and 48.51% at 120 DAT, respectively. As a result, we found that the effect of the treatment for soil amendments was in order of H > HZ > G.

• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.370-378
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• 1989

An Alkalophilic Bacillus circulans that can produce significant amount of cyclodextrin glucanotransferase (CGTase) was newly isolated from soil. The culture filtrate was successively purified by ($NH_4$)$_2$$SO_4$precipitation, DEAE-Sephadex column chromatography, and Sephadex G-100 column chromatography. The enzymatic properties, including molecular weight, optimal pH and temperature, stability, and kinetic parameters, were determined. The cyclodextrin synthesis reaction catalized by the purified CGTase was also studied. The sweet potato and corn starch were found to be the most suitable substrates with 60% conversion to cyclodextrin. The highest conversion was achieved at the CGTase concentration of 900-1,100 units/g of soluble starch. The purified CGTase could also catalize the transglycosylation on stevioside.