• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.451-454
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• 2003

Nonpoint source pollution of groundwater and subsurface water from irrigated agriculture is a major concern in many areas. In this study we aimed to investigate the effect of the water applied by irrigation in agricultural area on the transport of nitrogen and phosphorus originated from fertilizers applied to the surface of soil in agricultural activities. We first conducted investigation on the resdual concentrations of soil N and P in a selected agricultural area. And simulating the target area by column studies in the laboratory leaching extent of various components from the composite and urea fertilizers applied on the soil surface during irrigation was studied. Infiltration of water enhanced the leaching of nitrogen and phosphorus in both the rice paddy field soil and the patch soil. The downward N and P transport with infiltrating water was more pronounced in the patch soil column and the increased residual concentrations of N and P in the lower sections in the patch soil column was found with time.

• 자원리싸이클링
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• 제22권5호
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• pp.13-19
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• 2013

구리, 아연 및 납 등의 중금속으로 오염된 사격장 토양으로부터 중금속 성분을 제거하기 위한 친환경적인 공정을 개발하기 위해 구연산용액을 이용하여 중금속 침출거동에 대한 pH의 영향을 조사하였다. 구연산 침출실험은 구연산과 구연산나트륨을 혼합하여 pH를 조절한 용액을 이용하여 시료입도 $75{\mu}m$이하, 반응온도 $50^{\circ}C$, 구연산 농도 1 몰, 광액농도 5%, 교반속도 100 rpm, 그리고 침출시간 1 시간의 조건에서 진행하였다. 침출반응 전후의 pH 변화는 미미하여 침출에 미치는 수소이온농도의 직접적인 영향은 크지 않은 것으로 판단되었다. 구리, 아연, 납의 제거율은 pH가 증가함에 따라 감소하였고, 열역학적인 계산결과, 이와 같은 침출거동은 중금속 이온이 구연산염 이온종과 착이온을 형성하는 반응과 중금속이온이 수산화이온과 결합하여 수산화물로 침전하는 반응에 의해 결정되는 것으로 분석되었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.295-298
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• 2004

It was revealed that leaching of elements were partly inhibited because seawater contains plenty of dissolved ions than fresh water. On the other hands, the low activity coefficient and the formation of complex with chloride and sulfate play roles in enhancing element leachability. However, the pH buffaring capacity of seawater is the most important factor that makes the leaching of elements and its chemical behavior in the seawater system different from those in the fresh water environments. In general, the leaching from the weathered ash was smaller than that from the fresh ash. However, it was revealed that the leaching of Si, Fe, Al, Mn, phosphate, and some other elements were independent of ash weathering. They were dependant only on the pH of the solutions.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.1
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• pp.105-110
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• 2006

In order to utilize coal fly ash (hereafter : coal ash ) discharged from coal boiler as a material for civil engineering usage such as snow melter or soil improver, we have to prevent leaching hazardous elements such as fluorine boron and heavy metals from the coal ash because the leaching concentrations of some elements in the ash exceed the Japanese standards for environmental soil quality. Through the laboratory experiments and mill trials we confirmed that the leaching concentrations of fluorine, boron and heavy metals were maintained below their environmental standards by mixing with fixation chemicals and curing for a short time.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.372-378
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• 2003

This study investigates the fractional composition and the leaching characteristics of heavy metals in polluted soils due to mining activities. The fractionated composition of heavy metals is classified into five fractions, adsorbed, carbonate, reducible, organic and residual fraction. The status of humic substances in mine wastes of most sites are polyhumic except tailing from Sangdong mine. According to the sequential extraction procedures (SEPs), leaching probabilities of Cd in coal wastes and tailing are relatively low due to high percentage of residual fraction. 46.4% of Ni in tailings from Sangdong mine is probably leached under oxidized environment, and 39.4% of Cu in these tailings is readily extracted under strongly oxidized environment by organic fraction. According to leaching condition of pH 3.0 and pH 5.6, the amount of heavy metals leached out of coal wastes and tailing increases to 1/2 hours. At pH 3.0 and pH 5.6, concentration of Ni in tailing increases up three times of the initial value. Heavy metals released from coal wastes and tailing were not influenced significantly by leaching time.

• 한국지반환경공학회 논문집
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• 제3권4호
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• pp.29-35
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• 2002

본 연구는 유기질토를 토공재로서 활용할 목적으로 시료A(모래+유기질토)와 시료B(풍화토+유기질토)의 두 가지 시료를 유기질토 혼합비를 5%, 10%, 20%, 30%, 40%, 50%로 혼합하여 각종 실내시험을 실시하였다. 시료A, B의 용출시험에 의한 COD값은 순수 유기질토에 비해 상당히 낮은 값을 보였으며, 초기 침출수의 COD 값은 침출수 수질기준을 약간 상회하였지만 용출시작 4시간후의 COD 값은 매우 적게 나타났다. 모래와 유기질토의 혼합토는 유기질토 혼합비 40%(유기물함유량 11.3%)내에서는 성토재로서의 활용이 가능한 것으로 나타났으며, 풍화토와 유기질토의 혼합토는 유기질토 혼합비 30%(유기물함유량 16.4%)이내에서 토공재로서 활용이 가능하다고 판단되어진다.

• 한국환경과학회지
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• 제27권7호
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• pp.561-575
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• 2018

Agricultural soils around springwaters heavily affected by pesticide run-off and around wells considering the regional characteristics were collected at 24 stations in Jeju Island, and the physicochemical properties and adsorption and leaching characteristics of four nonionic pesticides (diazinon, fenitrothion, alachlor, and metalaxyl) were investigated. The values of the major soil factors affecting the adsorption and leaching of pesticides, namely, soil pH($H_2O$), organic matter content, and cation exchange capacity (CEC), were in the range of 4.64 ~ 8.30, 0.9 ~ 13.1% and 12.7 ~ 31.7 meq/100 g, respectively. The Freundlich constant, $K_F$ value, which gives a measure of the adsorption capacity, decreased in the order of fenitrothion > diazinon > alachlor > metalaxyl, which was identical to their lower water solubility. Among the collected soils, the $K_F$ value was very highly correlated with organic matter content ($r^2=0.800{\sim}0.876$) and CEC ($r^2=0.715{\sim}0.825$) and showed a high correlation with clay content ($r^2=0.473{\sim}0.575$) and soil pH($H_2O$) ($r^2=0.401{\sim}0.452$). The leaching of pesticides in the soil column showed a reverse relationhip with their adsorption in soils, i.e., the pesticides leached more quickly for the soils with lower values of organic matter content and CEC among the soils and for the pesticides with higher water solubility.

• 한국산학기술학회논문지
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• 제7권3호
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• pp.453-457
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• 2006

본 연구는 인산염을 이용하여 오염토양 내 존재하는 납을 불용성 금속인산염으로 고정화시킨 후 자연 상태에서 장기간의 용출특성을 평가하고자 칼럼실험을 수행하였다. 장기용출 실험결과 용출용액 중 납은 거의 검출되지 않았으며 잔류인의 농도도 0.1 mg/L 이하로 나타났다. 이는 납 오염토양에 액상인산염을 주입하여 형성된 hydroxypyromorphite가 장기적으로 안정한 화합물이기 때문으로 사료된다. 장기용출실험 후 칼럼 내 납의 이동특성은 미반응 토양에서는 수직방향으로 이동하는 것으로 나타난 반면에 반응토양에서는 안정한 상태를 유지하고 있었다.

• Advances in environmental research
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• 제3권4호
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• pp.321-335
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• 2014

Eight trace metals, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn, were measured in the urban soil of Guwahati City, Assam, India from 31 sites representing five different types of land use, residential, commercial, industrial, public utilities, and roadside. Cd and Co occurred in very low concentrations (Cd << Co) in all types of land use without any significant variation from one type of land use to another. Ni concentrations were more than those of Co, and the concentrations depended on land use pattern. Average Cr and Cu concentrations were ${\geq}100mg/kg$, but Cr had a significantly higher presence in industrial land use. Pb concentrations showed similar trends. The two metals, Mn and Zn, were present in much larger amounts compared to the others with values ${\geq}300mg/kg$. Industrial and roadside soil contained much more Mn while commercial soil was enriched with Zn. Toxicity Characteristic Leaching Procedure (TCLP) was used for elucidating the mobility characteristics of the eight heavy metals. Mn suffered the highest leaching from commercial land (9.9 mg/kg on average) and also from other types of land. Co, Cu and Pb showed higher leachability from commercial soils but the leached concentrations were less than those of Mn. The two metals, Zn and Ni, were leached from residential land in considerable amounts. The TCLP showed Mn to be the most leachable metal and Cr the least.

• 한국지하수토양환경학회지:지하수토양환경
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• 제8권3호
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• pp.45-55
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• 2003

연구의 목적은 광산활동에 의해 발생된 폐재에 의해 오염된 토양에 포함된 중금속의 존재형태와 용출특성에 대하여 비교 분석하는데 있다. 실험에 이용된 중금속 존재형태 분류는 다섯가지로 adsorbed, carbonate, reducible, organic과 residual 형태로 나누었다. 토양내 유기물의 함량 정도는 상동광산에서 발생된 광미가 석탄폐재보다 낮은 것으로 나타났다. 오염된 토양의 중금속 용출 실험에 의하면 석탄폐석과 광미내의 카드뮴의 경우 낮은 용출량을 보였으며, 대부분이 reduciblel fraction에서 용출된 것으로 관찰되었다 상동광산에서 발생된 광미에 포함된 니켈은 혐기성 상황이 되면 총량의 약 46.4％가 용출될 것으로 사료되며, 구리의 경우 약 39.4%가 용출될 것으로 판단된다. pH 3.0과 pH 5.6의 용출조건하에서 석탄 폐석과 광미의 용출랑의 점진적인 증가는 30분안에 이루어졌으며, 광미의 경우 니켈은 pH 3.0과 pH 5.6에서 용출 3시간까지 계속 증가되는 상태를 보였다.