• The Journal of Engineering Geology
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• v.30 no.4
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• pp.469-483
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• 2020

The results of long-term groundwater level and quality monitoring can be used not only as the basic data for evaluating the impact of various disasters including climate change and establishing responses, but also as key data for predicting and managing geological disasters such as earthquakes. Some countries use groundwater level and quality monitoring for researches to predict earthquakes and to assess the impacts of the earthquake disaster. However, a few cases in Korea report on individual groundwater quality factors (i.e., dissolved ions) observed before and after the earthquakes, being different from other countries. To establish the abnormality criteria for groundwater quality in Pohang, groundwater samples were collected and analyzed five times from 14 agricultural or private wells existing in Shingwang-myeon and Heunghae-eup. As a result of the analysis, it was found that Ca2+ was the dominant cation in Shingwang-myeon, while Na+ was the dominant cation in Heunghae-eup. The elevated NO3- concentration in Shingwang-myeon is contributed to the agricultural activity in the area. A high concentration of Fe was detected in a well on Heunghae-eup; the concentration exceeded the drinking water standard by nearly 100 times. Relatively higher dissolved ions were observed in the groundwater of Heunghae-eup, and it is considered as the result of the flow velocity difference and water-rock reaction accompanying the difference in bedrock and sediment characteristics. The groundwater of Shingwang-myeon appeared to be most affected by the weathering of granite and silicates, while that of Heunghae-eup was mainly affected by the weathering of silicates and carbonate. The background concentrations (baselines) of groundwater Shingwang-myeon and Heunghae-eup was identified through the survey; however, the continuous monitoring is required to monitor the possible changes and the repeatability of seasonal variation.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.3
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• pp.1-13
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• 2006

The aim of the study is to assess groundwater pollution hazard of Pohang city using the DRASTIC system developed by the US Environmental Protection Agency (USEPA). Hydrogeological spatial databases of the system include information on depth to groundwater, net recharge, aquifer media, soil media, topographic slope, hydraulic conductivity, lineament and potential pollution source. With GIS based on these hydrogeological databases and the DRASTIC system, the regional groundwater vulnerability of the study area was assessed. Then the vulnerability was overlaid with potential pollution source and the regional groundwater pollution hazard was assessed by administrative district. From the results of the study, areas where need the counter plan for groundwater pollution and where should be managed for the groundwater pollution, are identified.

• The Journal of Engineering Geology
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• v.15 no.4 s.42
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• pp.391-405
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• 2005

Chemical and isotopic analysis for stream water, shallow groundwater, intermediate groundwater and deep groundwater was carried out to grasp hydrogeochemical characteristics of groundwater in the Heunghae area, Pohang city. Water type of stream water and shallow groundwaters is typified as Ca-Cl type, intermediate groundwater is $Na-HCO_3$, and deep groundwater is prominent in Wa-Cl type. $HCO_3^-\;and\;SiO_2$ in shallow groundwater are originated from weathering of silicate minerals, whereas those of deep groundwaters are resulted from weathering of carbonate minerals. Ca and Mg ions in both shallow and deep groundwaters are resulted from weathering of calcite and dolomite. $SO_4^{2-}$ in shallow groundwater is originated mainly from pyrite oxidation. As well depth increases, pH and TDS increase, but Eh and DO decrease. Alkali metal contents(K, Na, Li) increases as well depth increases, but alkali earth metal(Mg, Ca) and hi concentrations increase as well depth decreases. Anions, halogen elements(F, Cl, Br), and $HCO_3$ contents increase as well depth increases. The average stable isotope value of the groundwater of each depth is as follows; deep groundwater: ${\delta}^{18}O=-10.1\%o,\;{\delta}D=-65.8\%_{\circ}$, intermediate groundwater: ${\delta}^{18}O=-8.9\%_{\circ},\;{\delta}D=-59.6\%_{\circ}$, shallow groungwater : ${\delta}^{18}O=-8.0\%_{\circ},\;{\delta}D=-53.6\%_{\circ}$, surface water : ${\delta}^{18}O=-7.9\%_{\circ},\;{\delta}D=-53.3\%_{\circ}$ respectively.

• Journal of Soil and Groundwater Environment
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• v.11 no.3
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• pp.20-30
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• 2006

Hydrogeochemistry of deep geothermal water (temperature: $42.2-47.9^{\circ}C$) at Heunghae, Pohang was evaluated using core logging, temperature and electrical conductivity (EC) logging before and after pumping tests, chemical analysis of geothermal water with depth, and observation of water quality variations during pumping tests. The geology of the area is composed of highly fractured marine sedimentary rocks. The hydrogeochemistry of geothermal water varies with drilling depth, distance from the coast, and pumping duration. According to the temperature and EC variations during 4 times of pumping tests, main aquifer of the area is considered as the fractured zones (540 to 900 m) developed in rhyolitic rocks. The high content of Na and $HCO_3$ in geothermal water can be explained by the inflow of deep groundwater from inland regulated by dissolution of silicates and carbonates. High TDS, Na and Cl concentrations indicate that the geothermal water was also strongly affected by seawater. The molar ratios of Na:Cl ($0.88{\sim}2.14$) and Br:Cl ($21.0{\sim}24.9{\times}10^{-4}$) deviate from those of seawater (0.84 and $34.7{\times}10^{-4}$, respectively), suggesting that water-rock interaction also plays an important role in the formation of water quality.

• The Journal of Engineering Geology
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• v.32 no.4
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• pp.559-569
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• 2022

This study investigated the acidification and mixing with seawater of groundwater, stream water, and reservoir water in the Hunghae area of Pohang City, as well as the source of water expelled to the stream by liquefaction induced by the Pohang earthquake on 15 November 2017. Geologically, the area consists of Tertiary sedimentary rocks. We collected six samples of groundwater, five of reservoir water, four of stream water, two of liquefaction water, and one of seawater to analyze the chemical composition and stable isotopes (𝛿D and 𝛿¹⁸O). Gogkang Stream flows eastward through the central part of the study area into the East Sea. The groundwater and reservoir water in the lower part of the stream are acidic (pH < 4), have a Ca(Mg)-SO₄ composition, and high concentrations of Al, Fe, and Mn, likely due to the oxidation of pyrite in Tertiary rocks. The groundwater in the upper part of the stream have a Ca(Na)-HCO₃(Cl) composition, indicating the mixing of seawater with the stream water. The 𝛿D and 𝛿¹⁸O isotope data indicate the isotopic enrichment of reservoir water by evaporation. Based on the chemical and isotopic data, it is inferred that the two samples of liquefaction water originated from alluvium water in a transition zone with stream water, and from deep and shallow groundwaters that has been infiltrated by seawater, respectively.

• Journal of agricultural medicine and community health
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• v.21 no.1
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• pp.61-73
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• 1996

This study conducted to determine the attitude on environment pollution by Pohang city citizens. 1,059 Pohang city citizens in the age group 20 and over were chosen and surveyed by officials's interview at Up, Myun and Dong during the period 6 September to 20 September 1995. The issue problems to be solved in Pohang city were traffic control 47.3%, environment pollution 22.7%, cultural institutions 11.6%, water service 9.9%, education system 5.1% and community security 2.1%. The 55.1% of subjects responded that responsibility for environment pollution is every citizens duty. The trash from houses were 'garbage'(48.1%), 'waste of life'(21.8%), 'reuse trash'(15.6%) and 'one use thing'(14.5%) in order. The 66.9% of subjects responded that the trash's standard envelopes can be easily tear and its texture is not good. The respondents sometimes or often had experienced foreign bodies, sediment in the water service supply. The 45.9% of the respondents use natural water as drinking water, and the water service supply(26.7%), underground water(17.0%) and buying water(9.3%) were followed. Pertaining to the air pollution(by percent) was pollution of the steel industry complex 78.0%, combustive gas 16.6% and construction dust 1.7%. The respondents at southern district complained of respiratory tract by air pollution and the respondents at northern district complained of the visual disturbance and the offensive odor(P<0.05). Water pollution problem is factory's wastewater 56.2%, home wastewater 36.4% and livestock's wastewater 5.6% in order. The respondents at southern district complained of the noise pollution by airplanes and factories at the afternoon and the respondents at northern district complained of the noise pollution by vehicles(P<0.05).

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.164-167
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• 2001

본 연구에서는 포항제철소에서 제철부산물로 발생되는 제강분진을 전처리 없이 산화촉매로 사용하여 김포 수도권 매립지의 침출수 처리공정에서 펜톤산화조에 유입되는 원수를 대상으 로 과산화수소를 이용한 연속식 산화처리 실험을 수행하였다. 먼저 회분식 실험결과를 바탕 으로 최적 반응조건에서 lab-scale 연속식 기초반응실험과 자체 설계.제작한 연속산화공정에서의 처리실험을 수행하였다. 또한 기존의 펜톤산화공정에서 Fe 공급원으로 사용되고 있는 FeSO$_4$.7($H_2O$)와의 반응성 비교실험도 수행하였다. 반응기간동안 일정 pH를 유지하기 위해 pH controller를 사용하였으며 침출수 수질은 CODcr로 나타내었다. 반응 pH 3.5, 체류시간 1 hr, 과산화수소 주입량 1,500mg/1에서 제강분진과 FeSO$_4$.7($H_2O$)를 각각 주입하여 수행한 연속처리 기초실험에서는 제강분진을 산화반응촉매로 사용한 경우에 침출수CODcr 처리율 62%, 과산화수소의 분해율 52%를 나타내었다. FeSO$_4$.7($H_2O$)를 산화반응 촉매로 사용한 경우에는 약 65-70%정도의 다소 높은 처리효율을 나타낸 반면에 과산화수소의 소비량은 제강분진의 경우보다 약 20%이상의 높은 값을 나타내었다. 연속산화공정 실험에서는 운전 3시간 이후에 유출수 중의 CODcr과 $H_2O$$_2$의 농도가 안정된 값을 나타내었다. 이 때 산화 반응조의 침출수 CODcr 제거효율은 약 43%이었으며, 처리수의 농도는 현재의 침출수 방류기준 이하로 나타났다. 결론적으로 침출수의 연속식 산화처리 실험결과, 처리효율과 경제성에서 제강분진의 산화촉매활용 공정의 개발 가능성이 매우 높은 것으로 나타났다.ell에 의해 완전분해 되었으며, 함께 존재시 TC는 Fe$^{\circ}$만으로는 분해가 되지 않았지만 cell에 의해 완전분해 되었으며, 함께 존재시 TCE분해에 저해작용을 미치는 것으로 나타났다.술의 첨가가 요구되고 있다. 따라서, 산성광산배수 오염지대에 대해 획일적으로 같은 처리방법을 채택하여 사용하는 것보다 각 지역 또는 광산산성폐수가 유출되어 나오는 광산폐기물의 특성 등을 고려하여 거기에 맞는 기술들을 복합적으로 또는 단독으로 사용하되 처리방법 채택 시 신중을 기할 것이 요망된다.정시에는 SeaWiFS 위성과 관련된 global algorithms 중에서 490nm와 555nm의 복합밴드를 포함하는 OC2 알고리즘(ocean color chlorophyll 2 algorithm)을 사용하는 것이 OC2 series 및 OC4 알고리즘보다 좋은 추정 값을 도출할 수 있을 것으로 기대된다.환경에서는 5일에서 7월에 주로 이 충체의 유충이 발육되고 전파되는 것으로 추측되었다.러 가지 방법들을 적극 적용하여 금후 검토해볼 필요가 있을 것이다.잡은 전혀 삭과가 형성되지 않았다. 이 결과는 종간 교잡종을 자방친으로 하고 그 자방친의 화분친을 사용할 때만 교잡이 이루어지고 있음을 나타내고 있다. 따라서 여교잡을 통한 종간잡종 품종육성 활용방안을 금후 적극 확대 검토해야 할 것이다하였다.함을 보이고 있다.X> , ZnCl$_{3}$$^{-}$같은 이온과 MgCl$^{+}$, MgCl$_{2}$같은 이온종을 형성하기 때문인것 같다. 한편 어떠한 용리액에서던지 NH$_{4}$$^{+}$의 경우 Dv값이 제일 작았다. 바. 본 연구의 목적중의 하나인 인체유해 중금속이온인 Hg(II), Cd(II)등이 NaCl같은 염화물