• Journal of Soil and Groundwater Environment
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• v.18 no.2
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• pp.36-44
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• 2013

The objectives of this study were to identify the characteristics of shallow groundwater from the oil-contaminated site for a long period and to evaluate the applicability of biopile technology to treat the soil excavated from it. The eight monitoring wells were installed in the contaminated site and pH, Electrical Conductivity (EC), Dissolved Oxygen (DO), Oxidation Reduction Potential (ORP), Temperature and the concentrations of major ions and pollutants were measured. The VOCs in soil gas were monitored during biopile operation and TPH concentration was analyzed at the termination of the experiment. The pH was 6.62 considered subacid and EC was 886.19 ${\mu}S/cm$. DO was measured to be 2.06 mg/L showing the similar characteristic of deep groundwater. ORP was 119.02 mV indicating oxidation state. The temperature of groundwater was measured to be $16.97^{\circ}C$. The piper diagram showed that groundwater was classified as Ca-$HCO_3$ type considered deep groundwater. The ground water concentration for TPH, Benzene, Toluene, Xylene of the first round was slightly higher than that of the second round. The concentration of carbon dioxide of soil gas was increased to 1.3% and the concentration of VOCs was completely eliminated after the 40 days. The TPH concentration showed 98% remediation efficiency after the 90 days biopile operation.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.34-37
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• 2001

폐수처리분야에 널리 사용되어 온 펜톤산화반응을 응용한 Fe$^{\circ}$/$H_2O$$_2$시스템을 이용하여 고농도 유류오염 미세호양(100$\mu\textrm{m}$이하)의 화학적 산화처리 실험을 수행하였다. 반응은 100$m\ell$, 삼각프라스크에 오염토양(5g)과 반응시약을 주입한 후 자석교반기를 이용하여 회분 식으로 진행하였으며 일정 시간(0, 1, 2, 4, 8, 24hr)별로 TPH를 측정하였다. 그리고 각 조건별 시간에 따른 반응특성을 살펴보았다. 일반적으로 알려진 펜톤산화반응의 수요 반응조건인 초기 pH /$H_2O$$_2$ 및 Fe$^{\circ}$의 주입농도, 그리고 초기 디젤오염농도의 조건을 변화하며 각 조건별 처리효과를 알아보았다. 본 연구결과에서 최적 pH조건은 3인 것으로 나타났으며, 분말철(Fe$^{\circ}$)과 $H_2O$$_2$의 주입농도를 증가함에 따라 오염토양의 TPH 제거효율도 비례적으로 향상되었다. 초기오염농도에 따른 최종 처리효율은 큰 차이가 없었으나. 고농도 오염일수록 제거된 디젤의 총량은 크게 나타나. 본 논문에서 제시한 방법이 고농도 오염토양일수록 더 큰 효과를 얻을 수 있음을 보여주었다. 대부분의 반응이 반응개시 후 약 8시간 이내에 이루어졌는데, 반응에 수반되는 pH 상승과 그에 따른 반응성의 저감효과를 일정 pH 조절에 의해 감소시킴으로써 반응성의 향상을 좀 더 높일 수 있을 것으로 판단된다. 결론적으로, Fe$^{\circ}$/$H_2O$$_2$시스템을 이용한 화학적 산화처리방법은 경제성과 처리성능에서 고농도 유류오염 미세토양의 효율적인 처리방안으로서 향후 적용 가능성이 높을 것으로 기대된다.

• Journal of Korea Soil Environment Society
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• v.2 no.3
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• pp.81-88
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• 1997

The purpose of this study is to assess contaminant transfer and environmental impacts to the surroundings by inadequate control of USTs. Several methodologies can be used in sampling procedure for the site assessment depending on the appearance of contaminants on the site and their types. In this case study because of site contaminants, randomized and/or triangle matrix techniques were used. As a result, the composition of materials in OO gas station were appeared in several status. From 1 to 2.5m depth, the soil was composed of silty sand and gravel, around 4m depth, weathered rock was appeared. Based on the preliminary and actual site investigation by DPT methodologies on the width and depth of the site with analysis of BTEX and TPH, no contamination was found in OO gas station, however, in one point because of careless dumping after refill by oil company, about 1731. 5 ppm of TPH appeared.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.1
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• pp.5-8
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• 2003

Alcohol abuse and cigarette smoking have been on the rise worldwide and it has been reported that alcohol and nicotine influence serotonergic neuronal activity in the dorsal raphe. Serotonin (5-hydroxytryptamine, 5-HT) has been implicated in the pathophysiology of various neuropsychiatric disorders. In the present study, the effects of alcohol and nicotine on the synthesis of 5-HT and the expression of tryptophan hydroxylase (TPH), the rate limiting enzyme of 5-HT synthesis, in the dorsal and median raphe of young rats were investigated via immunohistochemistry. The numbers of the 5-HT-positive and TPH-positive cells in raphe nuclei were reduced by alcohol and nicotine treatment, and these numbers were reduced more potently by co-administration of alcohol and nicotine. Based on the results, it can be suggested that the pathogenesis of alcohol- and nicotine-induced neuropsychological disorders involves alcohol- and nicotine-induced suppression of 5-HT synthesis and TPH expression in raphe, and that this may be of particular relevance in the consumption of alcohol and nicotine during adolescence.

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.1
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• pp.37-43
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• 1998

Batch experiments were conducted to study the dissolution behavior of gasoline components. First, the dissolution kinetics of gasoline components and the applicability of Raoult's law in predicting their solubilities were investigated. In addition, the effects of compositional change of gasoline due to evaporization on the solubilities of individual components and TPH were determined. The kinetics of gasoline-water man transfer was found to be very similar for most components except for MTBE, which is a major additive for commercial gasoline. At equilibrium, the gasoline-water partitioning coefficients of individual components showed a log-linear relationship with their pure solubilities, though the slope was a little less than that predicted by Raoult's law. The concentrations of the individual components in the gasolines concentrated by volatilization could be characterized by the initial increase followed by substantial decrease. Almost the same behavior was observed for their solubilities. The total solubility (TPH) of gasoline decreased rapidly with the initial volume reduction and gradually decreased afterwards. The solubilities of BTEX, the major regulatory compounds, decreased even faster than the TPH solubilities. It was concluded that the compositional change of gasoline by volatilization may greatly affect their leaching potential and the toxicity of the contacting groundwater. The toxicity reduction efficiency by evaporating gasoline could be much more than the mass removal efficiency.

• Journal of Environmental Health Sciences
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• v.49 no.2
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• pp.89-98
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• 2023

Background: Organophosphorus flame retardants (OPFRs) are a group of chemical substances used in building materials and plastic products to suppress or mitigate the combustion of materials. Although OPFRs are generally used in mixed form, information on their mixture toxicity is quite scarce. Objectives: This study aims to elucidate the toxicity and determine the types of interaction (e.g., synergistic, additive, and antagonistic effect) of OPFRs mixtures. Methods: Nine organophosphorus flame retardants, including TEHP (tris(2-ethylhexyl) phosphate) and TDCPP (tris(1,3-dichloro-2-propyl) phosphate), were selected based on indoor dust measurement data in South Korea. Nine OPFRs were exposed to the luminescent bacteria Aliivibrio fischeri for 30 minutes and the human hepatocyte cell line HepG2 for 48 hours. Chemicals with significant toxicity were only used for mixture toxicity tests in HepG2. In addition, the observed EC_x values were compared with the predicted toxicity values in the CA (concentration addition) prediction model, and the MDR (model deviation ratio) was calculated to determine the type of interaction. Results: Only four chemicals showed significant toxicity in the luminescent bacteria assays. However, EC₅₀ values were derived for seven out of nine OPFRs in the HepG2 assays. In the HepG2 assays, the highest to lowest EC₅₀ were in the order of the molecular weight of the target chemicals. In the further mixture tests, most binary mixtures show additive interactions except for the two combinations that have TPhP (triphenyl phosphate), i.e., TPhP and TDCPP, and TPhP and TBOEP (tris(2-butoxyethyl) phosphate). Conclusions: Our data shows OPFR mixtures usually have additivity; however, more research is needed to find out the reason for the synergistic effect of TPhP. Also, the mixture experimental dataset can be used as a training and validation set for developing the mixture toxicity prediction model as a further step.

• Journal of Nutrition and Health
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• v.40 no.7
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• pp.616-623
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• 2007

This study was carried out to investigate the Ca and Mg supplementation on the serum and liver lipid parameters in ovariectomized and Ca deficiency rats. Total 50 Sprague Dawley female rats (6 weeks) were divided into 5 groups and bred for 12 weeks: sham operated control group (SNCa), OVX Ca deficiency poop (OLCa) with Ca deficiency diet (0.1% Ca modified AIN-93N diet), OVX Ca deficiency & Mg supplement group (OLCaMg), OVX adequate Ca group (OACa; 0.5% Ca AIN-93N diet) and OVX adequate Ca & Mg supplement group (OACaMg). There were no significant difference among the five groups in serum total cholesterol, triglyceride and HDL-cholesterol levels. LDL-cholesterol of OVX groups was significantly higher than that of SNCa group (p < 0.01). AI (Atherogenic index), TPH (Total cholesterol/HDL-C) and LPH (LDL-C/HDL-C) of OACa group were significantly lower than those of OLCa groups. OACaMg group had significantly lower levels LDL, AI and TPH than OLCa group. There was no significant difference in lever cholesterol level. However, liver total fat content of OACa was significantly lower than that of OLCa. From the above the results, it is concluded that the accumulation level of calcium shows how the supplement of magnesium affects hyperlipidemia. Therefore, in order to prevent women#s hyperlipidemia after menopause, and to keep healthy, it is encourage able to consider how the supplement of magnesium relates calcium intake.

• Restorative Dentistry and Endodontics
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• v.21 no.2
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• pp.530-545
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• 1996

The purpose of this study was to investigate by spectrophotometry the changes in color parameters of composite resins after exposure to distilled water, filtered coffee, and artificial saliva. Five kinds of fine particle composite resin in experiment 1, and six kinds of composite resin in experiment 2 were used. In experiment 1, each group of composite resin was stored in distilled water at $4^{\circ}C$, $50^{\circ}C$, and filtered coffee solution at $4^{\circ}C$, $50^{\circ}C$. And then each specimen was measured by spectrophotometer. Measurements were repeated in 1 hour, 2 hours, 4 hours, 8 hours, 16 hours, 24 hours, and 48 hours. In experiment 2, all specimens of each brand were stored in distilled water at $37^{\circ}C$, artificial saliva not contained mucin at $37^{\circ}C$, and artificial saliva contained mucin at $37^{\circ}C$. All specimens of each brand were measured by spectrophotormeter in 1 week, 2 weeks, 4 weeks, 8 weeks, and up to 12 weeks. The results were as follows : 1. In cold coffee, five of fine particle composite resins showed ${\Delta}E{^*}_{ab}$ values less than 2. However, in hot coffee ${\Delta}E{^*}_{ab}$ values of Amelogen Universal and Prisma TPH were higher than those of Conquest Crystal, ${\AE}$litefil and Z100. 2. Z100 and ${\AE}$litefil had better cleansibility of extrinsic coffee staining than Amelogen Universal, Conquest Crystal and Prisma TPH. 3. In distilled water and artificial saliva not contained mucin, five of fine particle composite resin showed ${\Delta}E{^*}_{ab}$ values less than 2 up to 12 weeks. However, Silux Plus showed higher than ${\Delta}E{^*}_{ab}$ values of fine particle composite resin. 4. As an immersion solution for discoloration experiment, artificial saliva not contained mucin showed similar appearance as distilled water. However, artificial saliva contained mucin had different appearance from the others. 5. In artificial saliva contained mucin, ${\AE}$litefil, Prisma TPH and Z100 showed ${\Delta}E{^*}_{ab}$ values less than 1 up to 12 weeks. However, Silux Plus, Amelogen Universal and Conquest Crystal showed ${\Delta}E{^*}_{ab}$ values more than 1 up to 12 weeks. But, Conquest Crystal showed different characteristics of chromacity difference value(less chromatic) and lightness difference value(lighter) from Silux Plus and Amelogen Universal.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.152-157
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• 2003

Diesel-contaminated soils were ozonated for different times (0 - 900 min) and incubated for 9 wk to monitor petroleum hydrocarbons (PH)-degradative potential of indigenous microorganisms in the soils. Increased ozonation time decreased not only concentration of PH but also number of microorganisms in the soils. Microorganisms in the ozonated soils increased during 9-wk incubation as monitored by culture- and nonculture-based methods. Higher (1-2 orders of magnitude) cell number was observed by quantitative analysis of soil DNA using probes detecting genes encoding 165 rRNA(rrn), naphthalene dioxygenase (nahA), toluene dioxygenase (todC), and alkane hydroxylase (alkB) than microbial abundance estimated by culture-based methods. Such PH-degraders were relatively a few or under detection limit in 900-min ozonated soil. Further PH-removal observed during the incubation period supported the presence of PH-degraders in ozonated soils. Highest reduction (25.4%) of total PH (TPH) was observed in 180-min ozonated soil white negligible reduction was shown in 900-min ozonated soil during the period, resulting in lowest TPH-concentration in 180-min ozonated soil among the ozonated soils. Microbial community composition in 9-wk incubated soils revealed slight difference between 900-min ozonated and unozonated soils as analyzed by whole cell hybridization using group-specific rRNA-targeted oligonucleotides. Results of this study suggest that appropriate ozonation and subsequent biodegradation by indigenous microorganisms may be a cost-effective and successful remediation strategy for PH-contaminated soils.

• KSBB Journal
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• v.25 no.1
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• pp.73-78
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• 2010

In this study, recovering agent was produced with organic sludge and modified peat moss (MPM) in pilot plant mixer to recover oil contaminated soil, and field test of it was estimated using landfarming method. Oil contaminated soil recovering agent was thought to contain more microorganisms than raw waste sludge and was no problem to come onto the market because there were not any items of specified wastes. According to the results of TPH variation with time, it was observed the initial degradation velocity of oil with produced recovering agent was rapid up to 50% after 4 days, remarkably. Because the microorganisms in the organic sludge discharged from chemical plant already acclimated with oil, therefore, it could be estimated initial degradation velocity of recovering agent might be rapid. It was concluded that the oil contaminated soil recovering agent produced in this study have high marketability because of its two aspects on recycling of wastes and initial rapid degradation capacity.