• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.233-236
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• 2002

다양한 산업활동에 의하여 발생하는 6가 크롬 (Cr(Ⅵ))은 대표적인 토양 및 지하수 오염물질이다. Cr(Ⅵ)은 3가크롬(Cr(III))로의 환원에 의한 침전반응으로 이동성이 저하된다고 알려져 있다. 본 연구에서는 기존의 고형화/안정화 공정에 환원.분해 반응을 추가한 2가철 기반 분해성 고형화/안정화(Degradative Solidification/Stabilization)공정에 의한 Cr(Ⅵ) 처리 특성을 고찰하였다. 회분식 실험결과 cemen/Fe(II) system내에 Cr(Ⅵ)은 환원반응 뿐만 아니라 cement에 의한 침전에 의해서도 제거됨이 밝혀졌다. Cr(Ⅵ)의 제거속도는 Fe(II)의 반응당량에 비례하는 것으로 보여진 반면, cement/solution ratio에 따른 Cr(Ⅵ) 제거동역학의 차이는 그다지 크지 않았다

• Korean Journal of Environment and Ecology
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• v.11 no.1
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• pp.126-132
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• 1997

Nanji-do is an island in Seoul, the area is 272ha, and in which gad was piled up waste discharged from Seoul metropolitan for 15 years(form March 1978 to March 1993). The volume of waste is 92, 000, 000m$^{2}$. The actual vegetation area of Nanji-do is 191ha, and the area of woody plant is 31ha. The rest area is covered by herbaceaus plant. In actual vegetation area of woody plant, Robinia pseudoacacia community and Salix pseudo-lasiogyne community are 83%. The soil pH is alkaline, though general soil pH is acid in Seoul. There is no relation with soil condition and actual vegetation. The result of this study, actual vegetation of Nanji-do don't help the establishment of vegetation restoration after soil stabilization construction. And so following a countermeasure is proposed. 1) Selection of adequate species by an experiment of planting pioneer species, native species, and dietary species 2) Establishment of an adequate planting plan and development of slope stabilization method by planting of native species 3) Establishment of a restoration plan of animal ecosystem by survey for animal ecosystem

• Economic and Environmental Geology
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• v.54 no.4
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• pp.483-494
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• 2021

This study was carried out to investigate the feasibility of reducing clean cover soil using a flooded column test in arsenic-contaminated farmland reclamation of abandoned coal mine area that shows generally low or about worrisome level (25 mg/kg) of Korea soil environment conservation act unlike abandoned metal mine. During the monitoring period of soil solution for 4 months, chemical properties (pH, EC, ORP, Fe, Mn, Ca, and As) in each layer (clean soil cover and contaminated/stabilized soil) showed different variation. This result revealed that soil solution in stabilized or contaminated soil rarely affected that in cover soil. Whether stabilized or not, arsenic concentrations in the rice roots grown in the soil covers with the thickness of 40 cm decreased by 98% in compared with the that grown in the control soil. In case of the soil covers with 20 cm thickness on stabilized soil, it decreased by 80% and this was 22 percentage point higher than when the soil of lower layer was not stabilized. Thus, reducing clean cover soil could be possible in contaminated farmland soil reclamation if appropriate stabilization of contaminated soil is carried.

• Economic and Environmental Geology
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• v.56 no.5
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• pp.619-628
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• 2023

In this study, we investigated the feasibility of calcium sulfate fertilizer as a stabilizing agent for As and Hg contaminated farmland soil and its stabilization characteristics in 3 different physical forms (particulate, powder, and solution) through a pot experiment including 34 days of lettuce growth. As and Hg contents of the lettuce grown in the stabilized soils were decreased by at least 70%. However the lettuce yield of the soil stabilized with the solution agent was decreased by 46% due to the overabundance of the nutrients from the solution agent. Thus, if a solution-type agent is planned for agricultural farmland soil stabilization, additional tests for optimal dosage are needed to preserve vegetation growth. In Hg fractionation, a lower concentration of elemental fractions and a higher concentration of residual/sulfide fractions were identified in the soils stabilized with the solution, powder, and pariculate agents in descending order while there were no significant changes in As fractionation. Overall results suggest that calcium sulfate fertilizer can be used as a stabilizing agent, and a solution-type agent could be used when the operation of heavy machinery for the soil stabilization process is impossible.

• Economic and Environmental Geology
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• v.57 no.4
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• pp.417-429
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• 2024

To assess the effectiveness of stabilization techniques on the transfer of As and heavy metals in soil to rice plant, pot experiments were conducted using organic (biochar), inorganic (limestone-steel slag mixture), and microbiological (sulfate-reducing bacteria, SRB) stabilizers. The results showed that microbiological treatments, particularly when SRB and SO₄^2- were co-injected, achieved higher stabilization efficiencies for Pb, Cu, and Cd in soil solution by the end of the experiments (153 days). The transfer of Pb, Zn, Cu, and Cd to the rice stems, leaves, and husks was reduced across all stabilization treatments. Notably, in husks, the stabilization efficiencies of Pb, Zn, Cu, and Cd ranged from 30% to 65% for organic stabilizers and 23% to 69% for inorganic stabilizers, surpassing those achieved with microbiological stabilizers. This study highlighted the potential of SRB as an effective alternative or supplementary stabilizer to conventional options such as limestone, steel slag, and biochar in reducing the transfer of heavy metals to crops in paddy soils.

• Journal of Soil and Groundwater Environment
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• v.14 no.4
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• pp.45-53
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• 2009

This study concerned remediation of heavy metal contaminated farmland soils near abandoned mine, using stabilization method, with particular emphasis on the remediating the soils contaminated with multi-elements. In this study, stabilizing heavy metals based on 'In-situ chemical fixation' has been applied to the soil collected from an abandoned mine in Korea, using column test, with various stabilizing agents, including $FeSO_4$, $KMnO_4$, sludge (collected from coal mine drainage treatment pond), zero-valent iron (ZVI), zeolite and $CaCO_3$. Sixty five-days operation of the flow-through columns yield $FeSO_4\;+\;KMnO_4$ and zeolite are efficient on reducing As leaching from the soil. ZVI and sludge are reducing the leaching of Cu. Although $FeSO_4\;+\;KMnO_4$ seem to be efficient for most heavy metals, high pH in the initial stage of test enabled high leaching of the heavy metals, whereas fixation of the heavy metals maintain throughout the rest of the test period, with increasing pH up to around 6. Addition of some alkaline agent may inhibit the low pH during the application. The column test was also run as two set: one set incubated with deionized water for 72 hours prior to starting the test, and the other without incubation. The incubated set demonstrated better stabilizing efficiency, indicating the potential optimized operation method.

• Korean Journal of Environmental Agriculture
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• v.29 no.1
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• pp.47-53
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• 2010

The purpose of this study was to investigate the effectiveness of a stabilization treatment for As contaminated soil. A combination of hydrated lime, Portland cement, $FeCl_3{\cdot}6H_2O$, and NaOH were used as stabilizing agents. The effectiveness of stabilization treatment was evaluated by the Korean Standard Test (KST) method (1N HCl extraction). Sequential extractions were performed to investigate the As distribution after treatment. Following the application of the treatment, curing periods of up to 7 and 28days were investigated. The experimental results showed that a combination of hydrated lime/Portland cement was more effective than treatments of hydrated lime or Portland cement at immobilizing As in the contaminated soil. The treatment of 25wt% hydrated lime and 5wt% Portland cement was effective in reducing As leachability less than the Korean warning standard of 20 mg/kg. However, the treatments of hydrated lime and Portland cement failed to meet the Korean warning standard even when up to 30 wt% was used. The treatment utilizing hydrated lime and $FeCl_3{\cdot}6H_2O$ was not effective in properly reducing As leachability. The addition of $FeCl_3{\cdot}6H_2O$ was negative in terms of pH condition. Moreover, the treatment with hydrated lime/NaOH was effective in reducing As leachability but not as much as hydrated lime/Portland cement. The sequential extraction results indicated that the residual phase was greatly increased upon the treatment of hydrated lime/Portland cement. It was concluded that the hydrated lime/Portland cement treatment was the best among the other combinations studied at achieving trace As concentrations.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.1
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• pp.67-73
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• 2014

In this study, the residual heavy metals in the mine tailings, primarily treated by soil washing, were stabilized using phosphate salts. The concentrations of residual contaminants in the washed mine tailings were As (1,861 mg/kg), Cd (20 mg/kg), Cu (56 mg/kg), Pb (2,149 mg/kg), and Zn (633 mg/kg). They were stabilized with $CaHPO_4$, $Ca(H_2PO_4)_2{\cdot}H_2O$, and hydroxyapatite at 0.1 wt%, 1 wt%, and 10 wt% for 1, 3, 5, 7, and 14 days. It was found that 1 wt% $Ca(H_2PO_4)_2{\cdot}H_2O$ was optimum in our experiments, but the stabilization duration did not affect the efficiency. After stabilization with 1 wt% $Ca(H_2PO_4)_2{\cdot}H_2O$ for 1 day, the concentrations of arsenic and heavy metals, As (0.328 mg/L), Cd (0.250 mg/L), Cu (0.143 mg/L), Pb (0.359 mg/L), and Zn (2.622 mg/L), in TCLP leachate were below the RCRA-TCLP limits, which meant the contaminants in the treated mine tailings were stably immobilized.

• 농업기술회보
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• v.47 no.2
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• pp.25-26
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• 2010

• Journal of Korean Society of Environmental Engineers
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• v.32 no.6
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• pp.631-638
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• 2010

The objective of this study was to evaluate the efficiency of zerovalent iron and basic oxygen furnace slag on arsenic stabilization in soils. For this, arsenic (V) contaminated soil and roxarsone contaminated soil were incubated after incorporation with zerovalent iron (ZVI) or basic oxygen furnace slage (BOFS) at four different levels (0%, 1%, 3%, and 5%) for 30 days and then the residual concentrations of arsenic were analysed following extraction with aqua reqia, 1N HCl and 0.01 M $CaCl_2$. The total concentration of arsenic was 2,285 mg/kg in the As(V) contaminated soil and 6.5 mg/kg in the roxarsone contaminated soil. 1 N HCl extractable arsenic concentration in the As(V) contaminated soil was initially 1,351 mg/kg and this was significantly declined by 713~1,034 mg/kg following incubation with ZVI while BOFS treatment showed no effect on the stabilization of inorganic arsenate except 5% treatment which showed around 100 mg/kg reduction in 1N HCl extractable arsenic. Similarly, in the roxarsone contaminated soil 1N HCl extractable concentration of arsenic was reduced from 3.13 mg/kg to 0.69 mg/kg with ZVI treatment increased from 1% to 5% while BOFS treatment did not lead to any statistically significant reduction. Available (0.01M $CaCl_2$ extractable) arsenic was initially 0.85 mg/kg in the As(V) contaminated soil and this declined by 0.79 mg/kg following incorporation with 5% ZVI, which accounted for more than 90% of the available As in the control. When As(V)-contaminated soil was treated with BOFS, the available arsenic was increased due to competing effect of the phosphate originated from BOFS with arsenate for the adsorption sites. For the roxarsone contaminated soil, the greater the treatment of ZVI or BOFS, the lower the available arsenic concentration although it was still higher than that of the control.