• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.401-406
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• 2000

Spilling of petroleum hydrocarbons such as gasoline, motor oils, and diesel fuel from underground storage tanks (USTs) is a major source of contamination to ground water and soils. In response to the need of developing an effective and economical cleanup technique, this study investigates the effectiveness of using sonication to enhance the soil flushing method. The study involves laboratory testing, and the testing was conducted using a specially designed and fabricated device to determine the effect of sonication on contaminant removal. The sonication was applied at 20 kHz frequency under different power levels. Test soil was Joomoonjin Sand, and diesel fuel was used as a contaminant of soil flushing test. The results of the investigation show that sonication enhanced the contaminant removal from soils significantly, and the degree of enhancement varied with power levels of sonication. Based on the results of the study, it is concluded that the flushing method with sonication has a great potential to become an effective method for removing petroleum hydrocarbons from the contaminated ground.

• Journal of Environmental Health Sciences
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• v.19 no.2
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• pp.34-39
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• 1993

One hundred and eighty-seven water samples were collected from 23 of spring water, 2 of ground water, 1 of tap water in Pusan area and 3 of natural mineral waters. Total coliform group, fecal coliform, viable cell count and microflora were investigated to evaluate water quality of drinking water. The results were as follows: range and geometric mean value of total coliform and fecal coliform MPN's of spring water were 0~1,500/100 ml, 85/100 ml and 0~460/100 ml, 24/100 ml but coliform group was not detected in the samples of tap water and natural mineral water. Viable cell count of spring water, ground water and tap water were lower as 100 cell than the criteria for drinking water but that of natural mineral water was higher as 6.5X 10$^2$~7.4X 10$^3$ /ml. Predominant speces among the 219 strains isolated from the samples were 19.6% Aeromonas spp., 19.2% Enterobacteriaceae, 16% Acinetobacter spp. Especially, spring water and vessels were contaminated by Hafnia spp. and Providencia Spp, inhabitant of the oral cavity.

• Journal of environmental and Sanitary engineering
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• v.7 no.2
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• pp.83-94
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• 1992

Recently water demand is increasing as the industry prospers. The increase of water demand is followed by the increase of wastewater discharge which pollutes rivers and ground water extensively. These rivers, reservoirs and ground water are sources for drinking water and their contamination affects the quality of water supply and other potable water. In Korea there are 776 water treatment plants which supply drinking water from main rivers or reservoirs. Rivers are the biggest water source for drinking water is being contaminated, the innovation of treatment process is needed. The construction and operation of water supply facilities is under the control of the Ministry of Construction and the water supply offices of cities and provinces. However, drinking water quality is under the control of the bureau of sanitation in the Ministry of Health and Social Affairs. There are 33 items in drinking water quality standards of Korea. Trihalomethanes, Selenium, Diazinone and other three of pesticides have been included lately, The Ministry of Health and Social Affairs is planning to enhance. the level of $VOC_S$(Vola-tile Organic Compounds) standard. Drinking water quality standard is the goal to protect the quality of supply water and ground water. In order to protect the source water from domestic or industrial water, technological improvement and adequate investment should be urgently made. The ultimate goal of drinking water quality is safety and health of consumers. The more stringent the standard are, the better the water quality will be. As the drinking water quality standards become more stringent this year, various and positive solutions by the authorities concerned must be prepared.

• Proceedings of the KACD Conference
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• 2001.11a
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• pp.577-577
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• 2001

The lastest concepts in bonding are "total etch", in which both enamel and dentin are etched with an acid to remove the smear layers, and "wet dentin" in which the dentin is not blown dry but left moist before application of the bonding primer. Ideally, the application of a bonding agent to tooth structure should be insensitive to minor contamination from oral fluids. Clinically contaminations such as saliva, gingival fluid, blood and handpiece lubricant are often encountered by dentists during preparation of a restoration. The aim of this study was to evaluate the effect of contamination by hem-ostatic agents on shear bond strength of compomer restorations. One hundred and ten extracted human maxillary and mandibular molar teeth were collected. The teeth were cleaned from soft tissue remnant and debris and stored in physiologic solution until they were used. Small flat area on dentin of the buccal surface were wet ground serially with 400, 800 and 1200 abrasive paper on automatic polishing machine. The teeth were randomly divided into 11 groups. Each group was conditioned as follows: Group 1 : Dentin surface was not etched and not contaminated by hemostatic agents. Group2 : Dentin surface was not etched but was contaminated by Astringedent (Ultradent product Inc., Utah, U.S.A.). Group3 : Dentin surface was not etched but was contaminated by Bosmin (Jeil Phann, Korea.). Group4 : Dentin surface was not etched but was contaminated by Epri-dent (Epr Industries, NJ, U.S.A.). Group5: Dentin surface was etched and not contaminated by hemostatic agents. Group 6 : Dentin surface was etched and contaminated by Astringedent. Group7 : Dentin surface was etched and contaminated by Bosmin. Group8 : Dentin surface was etched and contaminated by Epri-dent. Group9 : Dentin surface was contaminated by Astringedent. The contaminated surface was rinsed by water and dried by compressed air. Group10 : Dentin surface was contaminated by Bosmin. The contaminated surface was rinsed by water aud dried by compresfed air. Group 11 : Dentin surface was contaminated by Epri-dent. The contaminated surface was rinsed by water and dried by compresfed air. After surface conditioning, F2000 was applicated on the conditoned dentin surface. The teeth were thermocycled in distilled water at $5^{\circ}C\;and\;55^{\circ}C$ for 1000 cycles. The samples were placed on the binder with the bonded compomer-dentin interface parallel to the lmife-edge shearing rod of the Universal testing machine(Zwick 020, Germany) running at a cross head speed of 1.0mmimin. There were no significant differences in shear bond strength between groups 1 and group 3 and 4, but group 2 showed significant decrease in shear bond strength compared with group 1. There were no significant differences in shear bond strength between group 5 and group 7 and 8, but group 6 showed significant decrease in shear bond strength compared with group 5. There were no significant differences in shear bond strength between group 5 and group 9, 10 and 11.

• Journal of Preventive Medicine and Public Health
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• v.10 no.1
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• pp.59-61
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• 1977

We are calling the erupting ground water as drugwater or mineral water in Korea and thinking those water is good for health from ancient. But most of them were used by mountainer as drinking water and food making water. Authors tried to investigate the evidence of contamination by user on the 10 erupting ground water and gained following results: 1. All of the mineral, waters on 10 area in Seoul were unfitable to drinking water standard. 2. In the view of the bacteriology 80% were contaminated by coliform group. 3. The highest value of the free carbon dioxide contents were 652.96 ppm at Sam Sun Mineral Water.

• Journal of environmental and Sanitary engineering
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• v.8 no.2
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• pp.99-108
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• 1993

It is well known that we should take 2L of drinking water per day to maintain our health. The drinking water quality is becoming worse owing to sewage discharge and industrial wastewater. Surface water is polluted by various kinds of contaminants and ground water were known as clean and unpolluted water, but through recent many reports the ground waters are also contaminated by waste disposal and intrusion of organic and bacterial movement. This research was undertaken to make a water index of water contamination by referringcations cations and anions. NH$_{4}$, Fe, Mn, and Pb are chosen as cations and $NO_3$, Cl, and $SO_4$ ions are chosen as anions to make a index, and the following water index was made as the contamination index. (Fe+Mn+Pb)/0.7+$(NH_4+NO_3+Cl+SO_4)$/10.5<6.0 By using ton Chromatography the cations and anions are rapidly analyzed and plotting the analyzed data to the equation, we can easily get the degree of contaminations by avoiding analysis of over 37 water parameters in several days. Of course this index of water contamination is not perfect and detail one, but in case of emergent case or to know the overall trends of contamination, it is convenient to use this index. Among the tested 5 kinds of samples the ground water showed contamination index of 6.87. Authors used the already published healthy index and tasty index and differentiated their degrees in detail.

• Journal of Environmental Science International
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• v.9 no.3
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• pp.241-252
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• 2000

Twenty-two water samples(fifteen groundwater and seven geothermal water samples) were collected to elucidate chemical characteristics of the ground and geothermal waters in the Haeundae hot spring area and its vicinity. Major and honor elements were analyzed for ground and geothermal water samples. The concentrations of $K^+$, Na+$, $Ca^{2+}$, $SO_4^{2-}$, $Cl^-$, ^F^-$ and $SiO_2$ were higher in the geothermal water samples than the groundwater samples except $HCO_3^- and Mg^{2+}$ ions. Based on the contents of Fe, Zn, Cu, Al, Mn and Pb, some of the ground and geothermal water samples are contaminated by anthropogenic sources. The ground waters shown on the Piper diagram belong to $Ca-HCO_3$ type, while the geothermal waters Na-Cl type. The graphs of $Cl^-$ versus $Na^+$, $Ca^{2+}, Mg^{2+}, K^+, SO_4^{2-} and HCO_3^-$ indicate that the groundwater is related partly with mineral-water reaction and partly with anthropogenic contamination, while the geothermal water is related with saline water. On the phase stability diagram, groundwater and thermal water mostly fall in the field of stability of kaolinite. This indicates that the ground and geothermal waters proceed with forming kaolinite. Factor and correlation analyses were carried out to simplify the physicochemical data into grouping some factors and to find interaction between them. Based on the Na-K, Na-K-Ca and Na-K-Ca-Mg geothermometers and silica geothermometers, the geothermal reservoir is estimated to have equilibrium temperature between 125${$\mid$circ}C$ and 160${$\mid$circ}C$.

• Journal of Korean Society on Water Environment
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• v.21 no.4
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• pp.403-409
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• 2005

Methyl tert-butyl ether (MTBE) contamination in groundwater often coexists with benzene, toluene, ethylbenzene, and xylene (BTEX) near the source of the plume. Then, groundwater contamination problems have been developed in areas where the chemical is used. Common sources of water contamination by BTEX and MTBE include leaking underground gasoline storage tanks and leaks and spills from above ground fuel storage tanks, etc. In oil-contaminated environments, anaerobic biodegradation of BTEX and MTBE depended on the concentration and distribution of terminal electron acceptor. In this study, effect of electron acceptor on the anaerobic biodegradation for BTEX and MTBE-contaminated soil was investigated. This study showed the anaerobic biodegradation of BTEX and MTBE in two different soils by using nitrate reduction, ferric iron reduction and sulfate reduction. The soil samples from the two fields were enriched for 65 days by providing BTEX and MTBE as a sole carbon source and nitrate, sulfate or iron as a terminal electron acceptor. This study clearly shows that degradation rate of BTEX and MTBE with electron acceptors is higher than that without electron acceptors. Degradation rate of Ethylbenzene and Xylene is higher than that of Benxene, Toluene, and MTBE. In case of Benzene, Ethylbenzene, and MTBE, nitrate has more activation. In case of Toluene and Xylene, sulfate has more activation.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.10a
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• pp.70-86
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• 2003

Despite its usability, TCE has been managed as a hazardous material due to the toxicity and many contamination cases were surveyed in some developed countries. U.S.EPA(Kram et al., 2001) suggested DNAPL characterization methods and approaches based on survey experiences at several sites. However, Korea has not the least assessment of contamination and trial of remediation, although there are a lot of doubtable areas where ground water would be contaminated with TCE. In this study, we try to assess the volume and extent of ground water contamination with TCE and delineate the contamination source zones in an industrial area. Ground water in this area flows through fractures and the contaminant TCE has the properties of high volatility, high density and low partitioning to soil material. Thus, we applied a variety of technical approaches to identify the contamination status; documentary, hydrogeochemical, hydrogeological and geological surveys. In addition, additional survey was performed based on the interim findings, which showed that ground water contamination was limited to the relatively small area with high concentrations to the deep place. The contamination source zone is estimated to be the asphalt test institute where a great deal of TCE has been used to analyze the amount of asphalt soluble in TCE since 1984. Based on the contamination characterization and a myriad of documents about ground water remediation, appropriate site remediation management options will be recommended later. This study is now under way and this paper was focused on describing the technical approaches used to achieve the goals of this study.

• The Journal of Engineering Geology
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• v.23 no.4
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• pp.427-434
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• 2013

The leachate from landfill (Andong city) contaminated by foot-and-mouth disease (FMD) contains 44%-50% hydrophilic organic matter, compared with 22%-27% in natural water bodies such as ground water, lake water, and river water. In such natural water, the organic matter content is reduced by the metabolism of microbes in the water. However, in the case of leachate-1 and -2, the concentrations of RTOC (refractory total organic carbon) and RDOC (refractory dissolved organic carbon) were higher than the initial TOC and DOC after burial. According to time elapsed after burial, the concentrations of RTOC and RDOC were decreased below the initial TOC and DOC. In the case of leachate-6 (386 days after burial), RDOC made up 91% of RTOC. This result shows that organic matter in the leachate was composed dominantly of RDOM, most of which was not removed by the metabolism of microbes. Hence, the presence and characteristics of RDOM provide a valuable indication of the effect of leachate on the quality of surface water and ground water. Such information is useful in understanding leachate environments.