• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2002년도 가을 학술발표회 논문집
• /
• pp.561-568
• /
• 2002

PFA(Paper Fly Ash) are reclaimed mainly or used in cement industry field as mixture agent in terms of materials recycling. Recently, research for recycling PFA as embankment materials or soil stabilization agent are undergoing in geotechnical engineering field. In this study, physical characteristics of PFA stabilization agent-soil admixtures are examined in change of water content, void ratio, consistency, grain distribution, specific gravity and density. Futhermore, the physical characteristics are compared with unconfined strength as engineering characteristics. Test results showed that unconfined strength and density are increased with increasing of PFA stabilization agent mixed ratio. On the other hand, specific gravity, void ratio and water content are decreased with increasing of PFA stabilization agent mixed ratio. It would be concluded that natural high water content ratio weak soil could be highly improved engineering and physical characteristics with PFA stabilization agent

• 상하수도학회지
• /
• 제27권3호
• /
• pp.395-404
• /
• 2013

The risk of pipe-bursting in multi-regional transmission mains consisting of 89 % of singled pipeline is so high that pipeline stabilization project is required such as renewal and replacement, pipe paralleling, emergency ties. Pipeline stabilization projects could be postponed at the step of initial decision-making because effect of this project is intangible benefit like activation of economic, improvement of welfare related to water. This study is to suggest quantified economical feasibility model for intangible benefit presumption to solve above problem. Cost reduction of emergency water supply, leakage, burst restore and energy efficiency improvement was altered and applied. As a result of economic analysis taking into account estimated benefit and cost under discount rate 5.5 %, service life 40 years, sufficient economic feasibility analyzed with B/C 2.45, NPV 317,700 million won, IRR 9.09 %.

• Environmental Engineering Research
• /
• 제24권4호
• /
• pp.654-661
• /
• 2019

This study assessed the stabilization of fluorine (F)-contaminated soil using calcium hydroxide (Ca(OH)₂) and the consequent changes in human health risk. The bioavailable F decreased to 3.5%, (i.e., 57.9 ± 1.27 mg/kg in 6% Ca(OH)₂-treated soil sample) from 43.0%, (i.e., 711 ± 23.4 mg/kg in control soil sample). This resulted from the conversion of water-soluble F to stable calcium fluoride, which was confirmed by XRD spectrometry. Soil ingestion, inhalation of fugitive dust from soil, and water ingestion were selected as exposure pathways for human health risk assessment. Non-carcinogenic risks of F in soils reduced to less than 1.0 after stabilization, ranging from 4.2 to 0.34 for child and from 3.0 to 0.25 for adult. Contaminated water ingestion owing to the leaching of F from soil to groundwater was considered as a major exposure pathway. The risks through soil ingestion and inhalation of fugitive dust from soil were insignificant both before and after stabilization, although F concentration exceeded the Korean soil regulatory level before stabilization. Our data suggested that substantial risk to human health owing to various potential exposure pathways could be addressed by managing F present in soil.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2010년도 추계 학술발표회
• /
• pp.1201-1212
• /
• 2010

In order to investigate on the effect of stabilization methods for rice paddies contaminated by heavy metals, a series of lab-scale model test was carried out by applying the characteristics of submerged Paddy soil. To perform the lab-scale model test, columns were made by acrylic with the dimension of diameter=10cm, thickness=0.5cm and were filled with soils which was contaminated were mixed with stabilization agents(lime stone 5% and steel refining slag 5% respectively). To manipulate the reduction condition, soils in the columns were submerged with distilled water. And then soil water and subsurface water in each column were sampled in the regular term and analysed the various physical and chemical properties.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제26권6호
• /
• pp.65-73
• /
• 2021

Since the amount of red mud, generated from aluminum smelting process as a by-product, has increased worldwide, the recycle and metal resource recovery from the red mud is becoming more important. In this study, in order to recycle the red mud as a soil stabilizer to remediate arsenic contaminated soils, neutralization of red mud was investigated. Red mud was neutralized by washing with distilled water and NaCl, CaCl₂, FeCl₃, and HCl solutions and heating at 200-800℃, and arsenic stabilization characteristics in soils were evaluated with the neutralized red mud. Although washing with distilled water was not effective in neutralizing red mud, the application of the washed red mud to soils lowered the soil pH compared to the application of untreated red mud. Among NaCl, CaCl₂, FeCl₃, and HCl solutions, washing with FeCl₃ showed the most effective in lowering pH of the red mud from pH 10.73 to pH 4.26. Application of the neutralized red mud in soils resulted in quite different arsenic stabilization efficiency depending on soil samples. In M1 soil, which showed relatively high arsenic stabilization efficiency by untreated red mud, the neutralization of red mud resulted in little effect on arsenic stabilization in soil. On the other hand, in M2 soil, which showed low arsenic stabilization efficiency by untreated red mud, the neutralization of red mud increased arsenic stabilization significantly. Soil characteristics such as clay minerals and pH buffering capacity seemed to affect reactions between red mud and soils, which resulted in different effects of the red mud application on soil pH and arsenic stabilization efficiencies.

• Environmental Engineering Research
• /
• 제8권3호
• /
• pp.152-161
• /
• 2003

• 한국물환경학회지
• /
• 제27권6호
• /
• pp.862-867
• /
• 2011

Pozzolanic-based stabilization/solidification (S/S) is an effective and economic remediation technology to immobilize heavy metals in contaminated soils. In this study, quick lime (CaO) was used to immobilize cadmium and zinc present in waste mine contaminated clayey sand soils. Addition of 5% quicklime to the contaminated soils effectively reduced heavy metal leachability after 2 bed volume operation below the drinking water regulatory limits. Lime addition was revealed to increase the immobilization for all heavy metals in tested pH ranges, so it could be an optimal choice for short-term remediation of heavy metal contaminated soil. The mass balances for these column tests show metal reduction of 92% for Cd and 87% for Zn of total resolved mass in case of 5% lime application.

• 플랜트 저널
• /
• 제13권4호
• /
• pp.38-40
• /
• 2017

본 연구는 기기냉각수 계통 Water Balance 정상화 방안을 위한 연구로 비용 대비 효과를 고려하여 최적안을 도출한다. Water Balance 검토를 위해 배관망해석프로그램이 사용되며, 프로그램의 신뢰성을 높이기 위해 초음파유량계로 현장 계측을 통해 시뮬레이션 계수 보정을 진행한다. 이를 토대로 다양한 Case Simulation을 통해 최적운전방안에 대해 도출하는 것이 목적이다.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
• /
• pp.1455-1471
• /
• 2009

In order to investigate on the effect of stabilization methods for rice paddies contaminated by heavy metals, a series of lab-scale model test was carried out by applying the characteristics of submerged Paddy soil. To perform the lab-scale model test, columns were made by acrylic with the dimension of diameter=10cm, thickness=0.5cm and were filled with soils which was contaminated were mixed with stabilization agents(lime stone 5% and steel refining slag 5% respectively). To manipulate the reduction condition, soils in the columns were submerged with distilled water. And then soil water and subsurface water in each column were sampled in the regular term and analysed the various physical and chemical properties.

• 한국지반환경공학회 논문집
• /
• 제25권5호
• /
• pp.5-13
• /
• 2024

본 논문에서는 유기오염물질인 benzyl butyl phthalate(BBP)에 오염된 퇴적토를 산/염기 개질활성탄을 이용한 퇴적토의 안정화 과정과 그 영향을 연구하였다. 실험을 통해 안정화제의 효율성을 평가하고, Lumbriculus variegatus를 이용한 생물학적 영향과 함께 개질활성탄의 혼합량 증가가 오염물질의 흡착에 미치는 영향을 분석하였다. 또한, low-density polyethylene를 사용한 공극수 내 유기오염물질 농도 측정을 통해 안정화제가 환경 내 오염물질의 이동을 어떻게 제한하는지에 대해 조사하였다. 연구 결과 Lumbriculus variegatus의 생존률이 90% 이상을 나타내었으며, 체내 BBP 축적 농도는 개질활성탄을 10% 혼합한 두 실험군보다 개질활성탄을 5% 혼합한 두 실험군이 약 2% 낮은 농도를 나타내었다. 수중으로의 용출량은 노출기간 7일 경과 후 모든 실험조건에서 대조군 대비 18% 이상 저감 되었으며, 노출기간 28일 후 모든 실험조건에서 25% 이상 저감된 효율을 확인하였다. 공극수의 농도를 측정하였다. 7일 노출 후의 결과는 기계혼합 실험군이 생물혼합 실험군 보다 높은 안정화율을 보였으며, 기계혼합 실험군에서, 개질활성탄을 10% 혼합한 실험군이 개질활성탄을 5% 혼합한 실험군 보다 1% 높은 안정화율을 보였다. 28일간 노출 후의 결과는 생물혼합 실험군이 기계혼합 실험군보다 높은 안정화율을 보였으며, 개질활성탄을 10% 혼합한 생물혼합 실험군이 개질활성탄을 5% 혼합한 실험군보다 약 0.1% 높은 안정화율을 보였다.