납 오염 논토양의 원위치 세척을 위한 FeCl₃의 Bench-scale 적용성 평가: 소석회를 이용한 토양산도 개선 및 납의 벼 전이특성

고일하,김정은,김지숙,장윤영,양재규,문덕현,최유림,지원현,Koh, Il-Ha,Kim, Jungeun,Kim, Gi Suk,Chang, Yoon-Young,Yang, Jae-Kyu,Moon, Deok Hyun,Choi, Yulim,Ji, Won Hyun 한국지하수토양환경학회 2018 지하수토양환경 Vol. No.

Pot experiments were conducted to assess the applicability of ferric chloride ($FeCl_3$) as a washing agent for laboratory scale in-situ soil washing of paddy soil contaminated with Pb. During the monitoring period for nearly 90 days, the concentrations of Fe and Mn in the soil solution were lower than that of control soil due to lime ($Ca(OH)_2$) amendment for pH recovery. Lime amendment also affected solubility and fractionation of Pb into soil matrix. The result showed that Pb concentrations of soil solution were consistently lower than that of control soil, and the concentration in the exchangeable fraction in washed soil decreased from 13 to 2 mg/kg. There was no significant difference of biomass yield of rice plant in each pots, and Pb contents in rice roots and grains in washed soil decreased to 50 and 78%, respectively, of the control soil. Therefore, $FeCl_3$ could be used as an acceptable in-situ washing agent for agricultural paddy soil if appropriate soil pH management is subsequently practiced.

석회석과 제강슬래그를 이용하여 안정화한 담수된 논토양의 비소 및 중금속의 거동변화

고일하,김의영,지원현,윤대근,장윤영,Koh, Il-Ha,Kim, Eui-Young,Ji, Won Hyun,Yoon, Dae-Geun,Chang, Yoon-Young 한국지하수토양환경학회 2015 지하수토양환경 Vol.20 No.1

The characteristics of As and heavy metals depend on the oxidation/reduction condition of the soil environment. The most heavy metals are immobilized by the reduction condition whereas As, Fe and Mn become more soluble. Therefore this study estimated the stabilization efficiency of the agricultural paddy soil in the vicinity of the abandoned mine using a flooded column test including analysis of the soil solution, contaminants fractionation and rice grain. Limestone and steelmaking slag were used as amendments for stabilization of the contaminated soil. In an analysis of the soil solution, the mobile characteristics of Fe and Mn, which were used as electron acceptors of the microorganisms, were controlled by increasing the pH by adding alkali amendments. This means that the contaminants combined with Fe and Mn can be stable under flooded reduction condition. However, the concentrations of cationic heavy metals (Cd, Pb, and Zn) were also decreased without amendments because the carbonates produced from microbial respiration increased the pH of the soil solution. In the amended soil, the specific sorbed fraction of As and carbonates fraction of heavy metals were increased when compared to the control soil at the end of the column test. Especially in heavy metals, the increase of carbonates fraction seems to be influenced by alkali amendments rather than microbial respiration. Because of the stabilization effect in the flooded paddy soil, the contents of As and Zn in rice grain from amended soil were lower than that of the control soil. But additional research is needed because of the relatively higher Pb content identified in the rice grain from the amended.

석회석과 제강슬래그를 이용한 오염토양 안정화에 따른 비소 및 중금속의 식물체 전이도 평가

고일하,이상환,이원석,장윤영,Koh, Il-Ha,Lee, Sang-Hwan,Lee, Won-Seok,Chang, Yoon-Young 한국지하수토양환경학회 2013 지하수토양환경 Vol.18 No.7

This study estimated stabilization efficiency of As and heavy metal contaminated agricultural soil in abandoned mine through pot experiment. Also contaminants uptake of plant (lettuce) was compared as function of amendment (limestone, steelmaking slag and the mixture of these) addition. In soil solution analysis, concentration of contaminants in soil solutions which added limestone or steelmaking slag were lower than that of the mixture. Especially in As analysis, concentration with 5% (wt) addition of steelmaking slag showed the lowest value among those with other amendments. This seems that As stabilization happens through Fe adsorption during precipitation of Fe by pH increasing. Leachability of As in stabilized soil by TCLP was represented similar result with soil solution analysis. However leachability of heavy metals in stabilized soil was similar with that of non-stabilized soil due to dissolution of alkali precipitant by weak acid. Contaminants uptake rate by plant was also lower when limestone or steelmaking slag was used. However this study revealed that concentration of contaminants in soil solution didn't affect to the uptake rate of plant directly. Because lower $R^2$ (coefficient of determination) was represented in linear regression analysis between soil solution and plant.

인공강우 모사를 통한 석회/유기퇴비 혼합물의 경사지 토양유실 억제효과

고일하,노훈,황원재,서형기,지원현,Koh, Il-Ha,Roh, Hoon,Hwang, Wonjae,Seo, Hyunggi,Ji, Won Hyun 한국지하수토양환경학회 2018 지하수토양환경 Vol.23 No.3

In a previous study, the feasibility of four materials (bentonite, steelmaking slag, lime and organic compost) to induce soil aggregate formation was assessed and the mixtures of organic compost and lime were chosen as most effective amendments in terms of cost benefit. This work is a subsequent study to evaluate the effectiveness of those amendments in reducing soil loss in $15^{\circ}$ sloped agricultural area by using rainfall simulation test. Three different soils were treated with two conditions of organic compost/lime mixtures (2% + 2%, 3% + 1%, w/w). In the amended soils, soil fertility was increased due to the increase of CEC, T-N, and T-P. During the rainfall simulation, suspended solid in run-off water from amended soil were reduced by 43% ~ 78%. When the content of organic compost was higher than that of lime, reduction of soil loss was also increased by 67% ~ 78%. Sediment discharge was also decreased by 72% ~ 96% in the amended soil. Similar to the suspended solid analysis, higher organic compost content led to more reduction of soil discharging, which implies organic compost is more effective than lime in reducing soil loss. The overall result suggests that the mixtures of organic compost and lime could be used as amendment materials to reduce soil loss in sloped farmland.

단풍잎돼지풀 기반 바이오차를 이용한 비소 및 중금속 오염 농경지의 안정화

고일하,김정은,김지숙,박미선,강대문,지원현,Koh, Il-Ha,Kim, Jungeun,Kim, Gi Suk,Park, Mi Sun,Kang, Dae Moon,Ji, Won Hyun 한국지하수토양환경학회 2016 지하수토양환경 Vol.21 No.6

Biochar, which has high alkalinity, has widely studied for amendment of soil that contaminated with heavy metals. The aim of this study is assessment of amendment for arsenic and heavy metals contaminated acidic agricultural soil using biochar that derived from buffalo weed (A. trifida L. var. trifida). Pot experiments were carried out including analysis of soil solution, contaminants fractionation, soil chemical properties and plant (lettuce) uptake rate. Arsenic and heavy metals concentrations in soil solution showed relatively low in biochar added experiments when compared to the control. In the heavy metals fractionation in soil showed decrease of exchangeable fraction and increase of carbonates fraction; however, arsenic fractionations showed constant. Soil chemical properties indicated that biochar could induce recovery of soil quality for plant growth in terms of soil alkalinity. However, phosphate concentration in biochar added soil decreased due to Ca-P precipitation by exchangeable calcium from biochar. Arsenic and heavy metals uptake rate of plant in the amended experiment decreased to 50% when compared to the control. Therefore biochar derived from buffalo weed can be used as amendment material for agricultural soil contaminated with arsenic and heavy metals. Precipitation of As-Ca and metal-carbonates are major mechanisms for soil amendment using char.

광산지역 수은 오염토양 안정화를 위한 석탄광산배수슬러지의 적용성 평가

고일하,권요셉,문덕현,고주인,지원현,Koh, Il-Ha,Kwon, Yo Seb,Moon, Deok Hyun,Ko, Ju In,Ji, Won Hyun 한국지하수토양환경학회 2020 지하수토양환경 Vol.25 No.1

This study assessed the feasibility of coal mine drainage sludge (CMDS) as a stabilizing agent for mercury contaminated soil through pot experiments and batch tests. In the pot experiments with 43 days of lettuce growth, the bioavailability of mercury in the amended soil and mercury content of the lettuce were decreased by 46% and 50%, respectively. These results were similar to those of the soil amended with the sulfide compound (FeS) generally used for mercury stabilization. Thus, CMDS could be an attractive mercury stabilizer in terms of industrial by-product recycling. Batch tests were conducted to examine mercury fractionation including reactions between the soil and acetic acid. The result showed that some elemental fraction changed to strongly bounded fraction rather than residual (HgS) fraction. This made it possible to conclude that mercury adsorption on oxides in CMDS was the major mechanism of stabilization.

석회석을 이용하여 안정화한 중금속오염 논토양에서 토양과 식물체(벼) 간의 중금속 전이특성

고일하,김의영,권요셉,지원현,주완호,김진홍,신복수,장윤영,Koh, Il-Ha,Kim, Eui-Young,Kwon, Yo Seb,Ji, Won Hyun,Joo, Wanho,Kim, Jinhong,Shin, Bok Su,Chang, Yoon-Young 한국지하수토양환경학회 2015 지하수토양환경 Vol.20 No.4

The agricultural soil, meets soil environmental standards whereas agricultural product from the same soil does not meet permissible level of contaminants, is identified in the vicinity of the abandoned mine in Korea. This study estimated the stabilization efficiency of Cd and Pb using limestone through the flood pot test for this kind of agricultural paddy soil. We had the concentration of the monitored contaminants in soil solution for 4 months and analyzed fractionations in soil and concentrations in rice plant. In soil solution of plow layer, the reductive Mn had been detected constantly unlike Fe. The concentrations of Mn in limestone amended soil was relatively lower than that in control soil. This reveals that the reductive heavy metals which become soluble under flooded condition can be stabilized by alkali amendment. This also means that Cd and Pb associated with Mn oxides can be precipitated through soil stabilization. Pb concentrations in soil solution of amended conditions were lower than that of control whereas Cd was not detected among all conditions including control. In contaminants fractionation of soil analysis, the decreasing exchangeable fraction and the increasing carbonates fraction were identified in amended soil when compared to control soil at the end of test. These results represent the reduction of contaminants mobility induced by alkali amendment. The Cd and Pb contents of rice grain from amended soil also lower than that of control. These result seems to be influenced by reduction of contaminants mobility represented in the results of soil solution and soil fractionation. Therefore contaminants mobility (phytoavailability) rather than total concentration in soil can be important factor for contaminants transition from soil to agricultural products. Because reduction of heavy metal transition to plant depends on reduction of bioavailability such as soluble fraction in soil.

유기퇴비를 이용한 급경사 농경지 토양유실 저감

고일하,강희천,권요셉,유찬,정문호,지원현,Koh, Il-Ha,Kang, Hui-Cheon,Kwon, Yo Seb,Yu, Chan,Jeong, Mun-Ho,Ji, Won Hyun 한국지하수토양환경학회 2020 지하수토양환경 Vol.25 No.4

The objective of this study was to investigate the feasibility of organic compost for reducing soil loss in 25% sloped farm land. For the study, laboratory and field experiment were performed. After nine weeks monitoring in pot test, hardness of the amended soil with organic compost (1%~3%, w/w) showed two times higher than the control soil. Furthermore, soil loss of that was decreased by 95% under rainfall simulation test. From the result of laboratory experiment, organic compost with 2% (w/w) was applied for field experimental plot. After six month from April to September, the amount of soil loss became 67% of the initial, and the growth of natural vegetation was not hampered. Therefore, organic compost can be used as amendment materials to reduce soil loss in sloped farmland.

납 오염 논토양의 원위치 세척을 위한 FeCl₃의 Bench-scale 적용성 평가: 세척전후 토양 특성변화

고일하,김지숙,장윤영,양재규,문덕현,최유림,고명수,지원현,Koh, Il-Ha,Kim, Gi Suk,Chang, Yoon-Young,Yang, Jae-Kyu,Moon, Deok Hyun,Choi, Yulim,Ko, Myoung-Soo,Ji, Won Hyun 한국지하수토양환경학회 2017 지하수토양환경 Vol.22 No.1

In a previous study, we assessed the feasibility of ferric chloride ($FeCl_3$) as a washing agent in bench-scale in-situ soil washing to remove Pb from agricultural paddy soil. Herein is a subsequent study to evaluate variations in soil properties after $FeCl_3$ soil washing in terms of fractionation and bioavailability of Pb and chemical properties of the soil. After soil washing, the soil pH decreased from 4.8 to 2.6 and the exchangeable fractions of Pb in the soil increased from 12 mg/kg to 15 mg/kg. Variations in the Pb fractionation of the soil increased Pb bioavailability by almost three-fold; however,the base saturation decreased by 75%. The concentrations of total nitrogen and available phosphate were similar before and after soil washing. The available silicate concentration significantly increased after soil washing but was two times lower than that of soil washed with HCl, which is widely used as a washing agent. This indicates that $FeCl_3$ can be an acceptable washing agent that protects the soil clay structure. The results suggest that soil amendment, such as liming, is needed to recover soil pH, reduce mobility of Pb, and provide exchangeable bases of Ca, Mg, and K as essential elements for the healthy growth of rice plants in reused soil that has been washed.

광산지역 비소오염 경사 농경지 토양의 안정화 및 유실 저감을 위한 석탄광산배수슬러지의 적용성 평가

고일하,권요셉,정문호,지원현,Koh, Il-Ha,Kwon, Yo Seb,Jeong, Mun-Ho,Ji, Won Hyun 한국지하수토양환경학회 2021 지하수토양환경 Vol.26 No.6

Soil aggregation begins with flocculation of clay particles triggered by interfacial reactions of polyvalent cation such as Ca²⁺ and Fe³⁺, and they are also known as important elements to control the mobility of arsenic in soil environment. The objective of this study was to investigate the feasibility of CMDS (coal mine drainage sludge) for soil loss reduction and stabilization of arsenic-contaminated soil in a 37% sloped farmland under rainfall simulation. The amount of soil loss decreased by 43% when CMDS was applied, and this result was not significantly different from the case of limestone application, which yielded 46% decrease of soil loss. However, the relative amount of dispersed clay particles in the sediment CMDS-applied soil was 10% lower than that of limestone-applied soil, suggesting CMDS is more effective than limestone in inducing soil aggregation. The concentrations of bioavailable arsenic in CMDS amended soil decreased by 46%~78%, which was lower than the amount in limestone amended soil. Therefore, CMDS can be used as an effective amendment material to reduce soil loss and stabilize arsenic in sloped farmland areas.