• 한국환경보건학회지
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• 제22권3호
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• pp.116-122
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• 1996

This study has been focused on the applicability of microwave treatment of soil contaminated by volitile organic chemicals. Substrates studied were sand and sandy soil. These substrates were impregnated with toluene, tetrachloroethylene, o-xylene and p-dichlorobenzene. The microwave treatment was conducted in a modified domestic microwave oven: 2450 MHz, 700 W. The sandy soil temperature added water went up rapidly to about 130$\circ$C for 4 minutes. And then, the temperature appeared to plateau out. A series of tests were performed to depict the effectiveness of microwave treatment technique to organic contaminants from soils. Removal efficiencies in sandy soil and sand were increased with increasing water content and exposure time. Microwave radiation penetrates the soil and heats water throughout the matrix. Therefore, addition of a certain amount of water to the contaminated soil can efficiently enhance the ability of the soil to absorb microwave energy and promote the evaporation of the volitile contaminants. And the vapour pressure of impregnated organic contaminants becomes lower. the removal efficiency becomes poor.

• 한국농공학회지
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• 제45권6호
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• pp.144-152
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• 2003

Laboratory experiments were carried out to investigate the influence of pore water contamination on the treatment effect of sandy soil which was solidified by Portland cement. In the experiments, setting time of hydraulic cement that was mixed with contaminated mixing water was measured using Vicat equipment and observed the tendency of setting process with the kind of contaminants, organic or inorganic components. It was shown that organic contaminants of the mixing water affect largely on the initial setting process of hydraulic cement and inorganics, expecially heavy metals, did not affect on the initial setting process, otherwise it was appeared that setting time of the sandy soil that was contaminated with inorganic components was apparently faster than the sandy soil that did not include inorganic components even though organic concentrations was relatively low level (COD=200∼300) in the mixing water. The results of unconfined compression strength test (UCST) were well consistent with the results of Vicat equipment test.

• Geomechanics and Engineering
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• 제16권3호
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• pp.247-255
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• 2018

Organic-sandy soils that contain abundant organic matters are widely encountered in estuarine cities. Due to the existence of organic matters, the strength and stiffness of this type of soil are significantly low. As a result, various geotechnical engineering problems such as difficulties in piling and constructing embankments and a lack of strength in poured concrete may occur in many estuarine sites; ground improvement such as cement treatment to this type of soils is needed. In this study, laboratory tests were performed to investigate the compressive strength of organic-sandy soil reinforced with primarily cement, in which the influences of several factors, namely types of cement and additional stabilizing agent, cement content, and water-cement ratio, were investigated and the orthogonal experimental design scheme was adopted. Based on the test results, an optimal permutation of these influencing factors is suggested for the reinforcement of organic-sandy soils, which can provide a useful reference for the relevant engineering practice.

• 농업과학연구
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• 제41권4호
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• pp.369-377
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• 2014

This study was carried out to evaluate the effect of rice husk (RHB) and food waste biochar (FWB) on upland soil with sandy loam texture, in terms of physico-chemical analysis, lettuce seed germination test, and orgainc carbon leaching experiment. RHB and FWB had different physico-chemical properties each other. Carbon to nitrogen ratio (C/N ratio) of RHB was 32, showing two times higher than that of FWB. FWB had high salt and heavy metal content, compared to RHB. This is probably due to different ingredients and production processing between two biochars each other. Results of germination test with Lettuce showed lower germination rate when FWB was applied because of higher salt concentration compared to control and RHB. Organic carbon leaching test using saturated soil column (${\Phi}75{\times}h75mm$) with $10MT\;ha^{-1}$ biochar application rate, showed higher saturated hydraulic conductivity in rice husk biochar treatment column, compared to control and food waste biochar treatment. The highest total organic carbon concentration in column effluent was lower than those in both of rice husk biochar and food waste biochar, whereas the differences was negligible after 9 pore volumes of effluent. Consequently, biochars from byproducts such as rice husk and food waste in sandy loam textured upland soil could enhance a buffer function such as reduction of leaching from soil, but the harmful ingredient to crops such as high salt and heavy metals could limit the agricultural use of biochars.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.125-130
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• 2004

This study has been assessed the influence of applying sewage sludge to soil amendments on the sorption properties, and leaching potential of three commonly used organophosphorus pesticides, Diazinon, Fenitrothion, and Chlorpyrifos. A sandy soil with a low content of organic carbon was treated with sewage sludge with a ratio sandy soil : sludge ratio of 30:1. The sorption was determined with the batch equilibrium technique. The sorption isotherms could be described by Freundlich equation. The Freundlich constant, K value which measures sorption capacity, were 3.97, 9.94, 22.48 for Diazinon, Fenitrothion, Chlorpyrifos in non-amended soil. But in amended soil, K value was 12.58, 28.47, and 61.21 for Diazinon, Fenitrothion, and Chlorpyrifos. The overall effect of sewage sludge addition to soil was to increase pesticides adsorption, due to the high sorption capacity of the organic matter. The effect of sludge on tile leaching of pesticides in the soil was studied using packed soil columns. Total recoveries of pesticides in soil and leachate with leaching in soil column, were in the range of about 73～84%, was reduced with the passage of time. Diazinon moved more rapidly than Chlorpyrifos in the unamended soil due to greater sorption and lower water solubility of Chlorpyrifos. Total amounts of pesticides leached from the sewage sludge amended soils were significantly reduced when compared with unamended soils. This reduction may be mainly due to and increase in sorption in amended soils, as a consequence of the increase in the organic matter content.

• 한국토양비료학회지
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• 제19권1호
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• pp.76-82
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• 1986

1. 항온기간중(恒溫期間中) $N_2O$의 경시적(徑時的) 발생량(發生量)은 항온(恒溫) 1일(日)과 10일경(日傾) 그리고 $N_2$의 발생량(發生量)은 1일(日)과 30일경(日傾)에 많았다. 2. 토양유기물함량별(土壤有機物含量別) 탈질량(脫窒量)은 현저(顯著)한 차이(差異)를 보이지 않았으며 시용유기물간(施用有機物間)에는 녹비(綠肥)>볏짚>퇴비(堆肥)>무시용(無施用)의 순서(順序)로 높았다. 3. 질소시비량(窒素施肥量)이 증가(增加)할수록 탈질량(脫窒量)은 증가(增加)되었으나 토양간(土壤間)에는 뚜렷한 차이(差異)가 없었음. 4. 탈질반응속도(脫秩反應速度)(계수(係數))는 토양유기물함량(土壤有機物含量)이 많고 역분해성유기물(易分解性有機物)을 시용(施用)할수록 증가(增加)되었음. 5. 토양중(土壤中) 탄소발생량(炭素發生量)과 탈질량(脫窒量)과의 관계(關係)에서 아산화질소(亞酸化窒素)는 정상관(正相關) 그리고 분자상질소(分子狀窒素)는 부상관관계(負相關關係)를 보였음. 6. 탄소(炭素) 1 mg이 소모(消耗)될때 약 4 mg의 $N_2O$와 3 mg의 $N_2$가 생성되었음.

• 한국토양비료학회지
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• 제48권6호
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• pp.751-760
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• 2015

Management of renewable organic resources is important in attaining the sustainability of agricultural production. However, nutrient management with organic resources is more complex than fertilization with chemical fertilizer because the composition of the organic input or the environmental condition will influence organic matter decomposition and nutrient release. One of the most effective methods for estimating nutrient release from organic amendment is the use of N mineralization models. The present study aimed at parameterizing N mineralization models for a number of organic amendments being used as a nutrient source for crop production. Laboratory incubation experiment was conducted in aerobic condition. N mineralization was investigated for nineteen organic amendments in sandy soil and clay soil at $20^{\circ}C$, $25^{\circ}C$, and $30^{\circ}C$. N mineralization was facilitated at higher temperature condition. Negative correlation was observed between mineralized N and C:N ratio of organic amendments. N mineralization process was slower in clay soil than in sandy soil and this was mainly due to the delayed nitrification. The single and the double exponential models were used to estimate N mineralization of the organic amendments. N mineralization potential $N_p$ and mineralization rate k were estimated in different temperature and soil conditions. Estimated $N_p$ ranged from 28.8 to 228.1 and k from 0.0066 to 0.6932. The double exponential model showed better prediction of N mineralization compared with the single exponential model, particularly for organic amendments with high C:N ratio. It is expected that the model parameters estimated based on the incubation experiment could be used to design nutrient management planning in environment-friendly agriculture.

• 유기물자원화
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• 제25권4호
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• pp.15-22
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• 2017

농경지에 유기물 자원을 시용하면 지력이 높아져서 작물의 수량이 높아진다. 본 연구의 목적은 유기물 자원을 밭 토양에 시용하였을 때 작물 수량 및 토양 물리성에 미치는 영향을 유기물 자원별로 비교하고자 하였다. 콩을 평야지인 수원의 사양토와 식양토 포장에서 재배하였으며, 온도 영향을 살펴보기 위하여 고랭지 평창의 사양토 포장에서도 수행하였다. 시험에 쓰인 유기물 자원은 볏짚퇴비, 돈분톱밥퇴비, 계분톱밥퇴비, 코코피트였으며, 콩 파종 전에 탄소 기준으로 동등한 수준으로 시용하였다. 무기질비료의 시용량은 토양검정한 분석치를 고려하여 결정하였다. 유기물 자원의 분해 특성을 살펴보기 위하여 항온배양실험을 실내에서 사양토를 대상으로 수행하였다. 분해 속도는 볏짚퇴비가 가장 높았으며, 돈분톱밥퇴비, 코코피트 순이었다. 유기물 자원의 시용에 따른 콩 수량의 증가 효과는 사양토에 비해서 식양토에서 높았다. 기상 비율의 증가 효과도 식양토에서 뚜렷하였다. 반면에 토양 입단 안정성의 증가 효과는 사양토에서 비교적 높았다. 볏짚퇴비가 모든 토양에서 콩 수량의 증가 효과가 가장 높았다. 코코피트의 콩 수량 증가 및 토양 물리성 개선 효과는 다른 유기물 자원에 비해서 높지 않았다. 따라서 밭작물 수량의 증대 및 토양 물리성의 개선을 위해서는 축분퇴비 등 다른 유기물 자원에 비해서 볏짚퇴비가 적합하였다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.367-367
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• 2017

Crimson clover, a legume crop, is a landscape crop and green manure crop that can be sowing in spring and autumn. Its red flower blooms in May, and serves various roles such as landscape composition, weeds suppressing, prevention of soil loss and nutrient on sloping land and supplying nitrogen and organic matter in soil. Thus, in order to utilize this crop in agriculture land, we evaluated the growth characteristics of crimson clover cultivated in four different soil textures, sand, sandy loam, loam, and clay loam. The nitrogen content of crimson clover was 15.8 g kg-1 and C/N rate was 20.3. Its growth was good in sandy loam and loam. Its plant height was 42.5 cm in sandy loam and 49.5 cm in loamy, respectively, which are approximately 20 cm longer than the sand and clay loam. The crimson clover in sandy loam and loam bloomed about seven days earlier than those in sand and clay loam. Regarding number of flower per hill and flower length, there were no difference between soil textures. Dry weight of crimson clover was 2.5 Mg ha-1, 2.3 Mg ha-1 each in sandy loam and loam. Therefore, it was approximately 0.8 ~ 1.1 Mg ha-1 higher than dry weight of sand and sandy loam. Plant height and dry weight of crimson clover was increased late harvest time. Nitrogen contribution were higher in loam and clay loam, when it was respectively 51.3 kg ha-1, 53.5 kg ha-1. Therefore, according to flowering properties and dry weight, the growth and development of crimson clover was finest in sandy loam and loam.

• 한국토양비료학회지
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• 제49권6호
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• pp.705-711
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• 2016

Crimson clover, a legume crop, is a landscape crop and green manure crop that can be sowing in spring and autumn. Its red flower blooms in May, and serves various roles such as landscape composition, weeds suppressing, prevention of soil loss and nutrient on sloping land and supplying nitrogen and organic matter in soil. Thus, in order to utilize this crop in agriculture land, we evaluated the growth characteristics of crimson clover cultivated in four different soil textures; sand, sandy loam, loam, and clay loam. The nitrogen content of crimson clover was $15.8g\;kg^{-1}$ and C/N ratio was 20.3. Its plant height was 42.5 cm in sandy loam and 49.5 cm in loamy, respectively, approximately 20 cm longer than the sand and clay loam. The crimson clover in sandy loam and loam bloomed about seven days earlier than those in sand and clay loam. Regarding number of flower per hill and flower length, there were no difference among the soil textures. Dry weight of crimson clover for sandy loam and loam was $2.5Mg\;ha^{-1}$ and $2.3Mg\;ha^{-1}$, respectively, $0.8{\sim}1.1Mg\;ha^{-1}$ higher than that of sand and sandy loam. Plant height and dry weight of crimson clover increased with delaying harvest time. Nitrogen contribution in loam and clay loam was $51.3kg\;ha^{-1}$ and $53.5kg\;ha^{-1}$, respectively. Therefore, in terms of flowering properties and dry weight, the proper soil texture for the growth and development of crimson clover was sandy loam and loam.