• 한국환경과학회지
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• 제9권5호
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• pp.437-441
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• 2000

A study on the removal of Pb ion from Pb-contaminated soil was carried out using ex-site extraction process. Tartaric acid (TA) and iminodiacetic acid sodium salt(IDA) as a washing agent were evaluated as a function of concentration reaction time mixing ratio of washing agent and recycling of washing agent. TA showed a better extraction performance than IDA. The optimum washing condition of TA and IDA were in the ratio of 1:15 and 1:20 between soil and acid solution during 1 hr reaction. The total concentrations of Pb ion by TA and IDA at three repeated extraction were 368.8 ppm and 267.5 ppm respectively. The recovery of Pb ion from washing solution was achieved by adding calcium hydroxide and sodium sulfide form the precipitation of lead hydroxide and lead sulfide and optimum amounts of sodium sulfide and calcium hydroxide were 7 g/$\ell$ for the TA washing solution and 4 g/$\ell$, 5g/$\ell$ for the IDA washing solution respectively. The efficiency of recycle for TA and IDA washing solution were 78.8% , 95.1%, and 89.2%, 96.6% at third extractions under $Na_2S$ and $Ca(OH)_2$, respectively.

• The Korean Journal of Ecology
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• 제22권5호
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• pp.265-270
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• 1999

전라남도의 해안에 방치된 염전에 생육하고 있는 식생에 대하여 군락 분류학적 연구와 토양의 특성에 대한 연구가 수행되었다. 본 연구는 종조성을 바탕으로 Mueller-Dombois와 Ellenberg 법에 따라 수행되었다. 본 연구의 목적은 전남 해안에 방치되어 있는 폐염전의 식물군락분류를 통한 식생형을 규정하고, 군락생태를 밝히는데 있다. 폐염전에 분포하는 일년생 초본 염생식물군락은 퉁퉁마디군락, 칠면초군락, 해홍나물군락, 가는갯능쟁이군락, 갯개미자리군락으로 밝혀졌다. 그리고 다년생 초본 염생식물군락으로는 갯개미취군락, 천일사초군락, 갈대군락으로 분류되었다. 본 연구의 결과는 해안 습지 식생에 대한 군락분류 및 구성종에 대한 정보의 축적을 가능하게 하고, 아울러 해안 습지 생태계 보전을 위한 기초자료로 유용한 정보를 제공한다.

• Geomechanics and Engineering
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• 제37권5호
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• pp.499-510
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• 2024

In northern China, abundant summer rainfall and a higher water table can weaken the soil due to salt heave, collapsibility, and increased moisture absorption, thus the chlorine saline soil (silty clay) needs to be stabilized prior to use in road embankments. To optimize chlorine saline soil stabilizing programs, unconfined compressive strength tests were conducted on soil treated with five different stabilizers before and after soaking, followed by field compaction test and unconfined compressive strength test on a trial road embankment. In situ testing were performed with the stabilized soils in an expressway embankment, and the results demonstrated that the stabilized soil with lime and SH agent (an organic stabilizer composed of modified polyvinyl alcohol and water) is suitable for road embankments. The appropriate addition ratio of stabilized soil is 10% lime and 0.9% SH agent. SH agent wrapped soil particles, filled soil pores, and generated a silk-like web to improve the moisture stability, strength, and stress-strain performance of stabilized soil.

• 인간식물환경학회지
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• 제23권6호
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• pp.625-636
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• 2020

Background and objects: Soil contamination caused by CaCl₂ that is used to deice slippery roads in winter is now recognized as one of the major causes of damage of roadside plants. The aim of this study is to identify the salt mitigation effects of planting Chrysanthemum zawadskii and using a soil conditioner. Methods: The study was conducted at the site where Pinus densiflora f. multicaulis was planted on the roadside between Konkuk University Sageori and Danwol Samgeori located in Chungju-si. We classified the soils collected from the field experimental site according to the degree of the damage caused by deicing agents and divided the site into six blocks of three 80 × 80 cm plots replicated by treatment type. Three selected plots were treated with loess-balls on the soil surface (high salinity with loess-balls, medium salinity with loess-balls, low salinity with loess-balls) and three were left as an untreated control (H = high salinity, M = medium salinity, L = low salinity). The soil properties were measured including pH, EC and exchangeable cations as well as the growth of Chrysanthemum zawadskiia. Results: In the results of soil analysis, pH before planting Chrysanthemum zawadskiia was 6.39-6.74 and in September, five months after planting, the acidity was reduced to 5.43-5.89. Electrical conductivity (EC) was measured to be H > M > L with the higher degree of damage by deicing agents. The analysis of deicing exchangeable cations showed that the content of Ca²⁺ of soils were significantly correlated to deicing exchangeable cations (Ca²⁺, Na⁺, Mg²⁺) in the shoot part of Chrysanthemum zawadskii. The loess-ball treatment showed a lower content of deicing exchangeable cations than the treatment where Chrysanthemum zawadskiia was planted. Conclusion: In this study, the use of a new system made of loess-balls is proposed as a soil conditioner to protect soils from the adverse effects of road deicing salts. These data suggest that treatment of soil conditioners and planting Chrysanthemum zawadskiia are effective in mitigation of salt stress on the soils damaged by deicing agents.

• 한국환경복원기술학회지
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• 제11권5호
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• pp.60-71
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• 2008

Through analyzing the specific physicochemical alterations in depth-based soil at reclaimed dredging area, the baseline data were provided for developing the reclaimed dredging area as natural landscape planting sites and ecological-landscape sites based on the soil improvement technology. There was no physical disturbance for 15 to 20 years in Gwangyang Bay reclaimed dredging area after reclamation. Physicochemical examinations of the soil were performed based on the vertical depth. Results of physicochemical analysis such as pH, electric conductivity, total salt contents, silt, clay contents, available phosphorus, calcium, magnesium, sodium, chlorine, and sodium-adsorption ratio showed increasing patterns with the depth while total organic contents, total nitrogen, and sand showed decreasing patterns. Potassium as an exchangeable cation, showed similar distribution patterns between the shallow and deep soil. This result strongly implied that long-term exposure to natural rainfall in reclaimed dredging area altered soil characteristics related to salinity. This research demonstrated that there were no remarkable differences in physicochemical characteristics at soil depth and groundwater table height, suggesting a baseline data for developing reclaimed dredging area. Additional investigation is required for different reclaimed dredging areas. Also, additional monitoring and examination are need on plant communities and time variable alteration in the soil to test the feasibility of reclaimed dredging areas as natural landscape planting sites and ecological-landscape sites.

• 한국산림과학회지
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• 제73권1호
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• pp.1-8
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• 1986

임목(林木)의 내염성(耐鹽性)을 검사(檢討)하기 위하여 우리나라 동해안(東海岸) 일부(一部) 삼림(森林)에 대한 수종분포(樹種分布)와 염분농도(鹽分濃度)의 관계(關係)를 조사(調査) 분석(分析)하였는데 그 결과(結果)를 요약(要約)하면 아래와 같다. 1) 동해안(東海岸) 수종분포(樹種分布)의 주(主) 구성종(構成種)은 곰솔, 소나무, 해당화, 싸리, 족제비 싸리, 떡갈나무, 진달래, 아까시나무 등(等)이었다. 2) 정선(汀線)으로부터 내륙(內陸)쪽으로 들어오면서 200m까지는 곰솔이 우점종(優點種)을 이루고 있었고 해당화의 분포(分布)가 끝나는 지역(地域)이며, 200-300m 구간(區間)은 곰솔의 분포(分布)가 거의 끝나는 반면(反面) 소나무가 우점종(優點種)을 이루고 있었다. 3) 해발고(海拔高) 50m까지는 곰솔이 우점종(優點種)을 이루나 그 이상(以上)부터는 소나무가 우점종(優點種)을 이루고 있었다. 4) 토양중(土壤中)의 NaCl농도(濃度)는 정선(汀線)으로부터 내륙(內陸)쪽으로 멀어질수록, 해발고(海拔高)가 높아질수록, 토심(土深)이 얕을수록 감소(減少)하는 경향(傾向)을 보였다. 5) pH는 정선(汀線)으로부터 내륙(內陸)쪽으로의 거리(距離)나 해발고(海拔高)의 차(差)에 따라 차이(差異)를 인정(認定)할 수 없었지만 표토(表土)와 심토(深土)(지하(地下) 50cm 깊이)의 pH 는 7.0과 6.5로 토심(土深)에 따라 현저(顯著)한 차이(差異)가 있었다. 6) 곰솔은 토양(土壤)의 NaCl농도(濃度)가 100vpm 이상(以上)에서, 소나무는 100vpm 이하(以下)에서 분포밀도(分布密度)가 각각(各各) 증가(增加)함을 알 수 있었고, 해당화는 100vpm 이상(以上)에서만 분포(分布)를 볼 수 있었다. 7) 수체내(樹體內)의 NaCl농도(濃度)는 정선(汀線)으로부터 내륙(內陸)을 향(向)하여 들어오면서 감소(減少)하는 경향(傾向)으로 150m까지는 급감소(急減少)를 나타내었고 이후(以後)는 서서히 감소(減少)하였다. 수체내(樹體內)의 최대(最大) NaCl농도(濃度)는 엽(葉)이 600ppm, 지(枝)가 350ppm, 근(根)이 250ppm 정도(程度)였다.

• 한국응용곤충학회지
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• 제15권4호
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• pp.185-191
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• 1976

맥작에 있어서 문제 광엽잡초를 2,4-D에 의하여 방제하기 위하여 처리약량, 처리시기, 토성별로 실험을 실시하였던 바 그 결과를 요약하면 다음과 같다. 1) 10a 당 $40\%$유제 2,4-D amine salt 70cc를 유효분벽 종지기에 처리하였을 때 보리에 거의 약해를 주지 않고 대부분의 광엽잡초의 방제가 가능하였다. 2) 2,4-D의 최적처리시기는 유효분벽 종지기이며, 이보다도 빠르거나 늦게 될 때에는 약해를 내어 수량감소를 가져왔다. 3) 보리의 내성이 가장 강한 시기에 최적약량처리가 될 때에는 토성에 환계없이 2,4-D의 적용이 가능함을 시사하였다.

• 한국작물학회지
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• 제49권5호
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• pp.407-409
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• 2004

Thirty-nine out of eighty-five barley varieties/strains survived until heading stage in the saline experimental field $(0.03-0.05\%\;salt)$ and they were used for pollen study. Light and scanning electron microscopic observations revealed two distinctive types of barley pollens: one transparent and small in size and the other dark and larger. In addition, both types of pollens were stained with Alexander's stain and it was found that the smaller and transparent pollen was cytoplasm-devoid (CD) while the larger pollen was cytoplasm-rich (CR). Sixteen out of 39 barley varieties/lines grown in the saline soil had CR pollens, which were rarely observed in the barley plants grown in the non-saline soil. Moreover, it was observed that salt stress severely reduced seed setting in the varieties having degenerated pollens. These results suggest that salt stress affects the fertility of barley pollen. The sterile pollen was undersized and lack of cytoplasm probably due to abortion. Furthermore, a varietal difference existed in the response of pollen development to salt stress.

• Geomechanics and Engineering
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• 제18권2호
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• pp.189-203
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• 2019

Brine leakage is a common phenomenon during construction facilitated by artificial freezing technique, threatening the stability of frozen wall due to the continual thawing of already frozen domain. This paper takes the frequently encountered soft clay in Wujiang District as the study object, and remolded specimens were prepared by mixing calcium chloride solutions at five levels of concentration. Both the deformation and pore water pressure of frozen specimens during thawing were investigated by two-stage loading tests. Three sections were noted from the changes in the strain rate of specimens during thawing at the first-stage load, i.e., instantaneous, attenuated, and quasi-stable sections. During the second-stage loading, the deformation of post-thawed soils is closely correlated with the dissipation of pore water pressure. Two characteristic indexes were obtained including thaw-settlement coefficient and critical water content. The critical water content increases positively with salt content. The higher water content of soil leads to a larger thaw-settlement coefficient, especially at higher salt contents, based on which an empirical equation was proposed and verified. The normalized pore water pressure during thawing was found to dissipate slower at higher salt contents, with a longer duration to stabilize. Three physical indexes were experimentally determined such as freezing point, heat conductivity and water permeability. The freezing point decreases at higher salt contents, especially as more water is involved, like the changes in heat conductivity. The water permeability maintains within the same order at the considered range of salt contents, like the development of the coefficient of consolidation. The variation of the pore volume distribution also accounts for this.

• 한국토양비료학회지
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• 제8권2호
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• pp.53-60
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• 1975

소채(蔬채)의 연작(連作)과 다비(多肥)에 의(依)하여 염류(鹽類)가 과잉집적(過剩集積)된 비닐하우스 내(內) 토양(土壤)에 대(對)하여 관수량(灌水量)과 관수회수(灌水回數)에 따른 제염효과(除鹽效果)와 제염(除鹽)이 토마토 수량(收量)에 미치는 영향(影響)을 조사(調査)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 관수량(灌水量)이 증가(增加)할수록 또 1회(回)에 전량(全量)을 관수(灌水)하는 것 보다 2~3회에 나누어서 관수(灌水)하는 것의 제염률(除鹽率)이 높았다. 동일량(同一量)의 관수량(灌水量)에 대(對)한 제염효율(除鹽效率)은 사양토(砂壤士)보다 식양토(埴壤士)에서 높았으며, 150mm 관수시(灌水時) 토양(土壤)의 깊이 30cm 까지의 제염율(除鹽率)은 미사질식양토(微砂質埴壤土)에서 50%, 사양토(砂壤土)에서 34% 이었다. 2. 관수(灌水)에 의(依)한 제염(除鹽)으로 토마토의 수량(收量)은 증가(增加)하였으나, 제염율(除鹽率)과는 반드시 일치(一致)하지는 않았다. 100mm(50-50), 150mm(50-50-50, 혹(或)은 100-50) 및 200mm(100-100) 관수(灌水)한 구(區)의 증가(增收)가 인정(認定)되었다. 3 토마토의 수량(收量)(${\hat{Y}}$)와 표토(表土)의 전기전도도(電氣傳導度)(1 : 5)와는 다음과 같은 관계(關係)가 인정(認定)되었다. 사양토(砂壤士);${\hat{Y}}=1,737.0+437.5X-290.5X^2$ $(R=0.632^{**})$ 미사질식양토(微砂質埴壤士);${\hat{Y}}=1,542.3+454.1X-275.0X^2$ $(R=0.622^{**})$ 4. 수량(收量)과 토양(土壤)의 침출성(浸出性) 양(陽)ion중(中) calcium, magnesium의 함량(含量)과는 상관(相關)이 인정(認定)되지 않았으나, sodium, potassium sodium 함량(含量) 및 sodium과 calcium과의 비(比) (Na/Ca)과 부상관(負相關)이 인정(認定)되었다.