• The Journal of Fisheries Business Administration
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• v.53 no.2
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• pp.58-72
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• 2022

Fishery products play an important role in Korean food culture, and awareness of the safety of fishery products is increasing in the seafood market. Against this backdrop, Japan has announced a plan to release radioactive water to the sea from 2023. In the case of Korea, it is adjacent to the area to be discharged, so there are concerns about securing the safety of marine products. Therefore, it is necessary to analyze the change in perception and impact of marine product consumers due to the discharge of contaminated water and to study appropriate countermeasures when discharging contaminated water from nuclear power plants. In this study, the current status of radioactive contaminated water discharge in Japan was summarized, and a survey was conducted on the change in the consumption perception of marine products according to the discharge of contaminated water to analyze the factors affecting the consumption change of domestic consumers. According to the survey, 85.3% of the respondents said that it will affect the purchase of domestic marine products if Japan starts discharging contaminated water from nuclear power plants. Moreover, 85.5% of the respondents said it will affect the purchase of imported marine products.

• Progress in Superconductivity and Cryogenics
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• v.22 no.2
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• pp.7-11
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• 2020

When rivers and lakes are contaminated with numerous contaminants, usually the contaminants are finally deposited on the sediments of the waterbody. Many clean up technologies have been developed for the contaminated sediments. Among several technologies dredging is one of the best methods because dredging removes all the contaminated sediments from the water and the contaminated sediments can be completely treated with physical and chemical methods. However the most worried phenomenon is suspension of fine particles during the dredging process. The suspended particle can release contaminants into water and resulted in spread of the contaminants and the increase of risk due to the resuspension of the precipitated contaminants such as heavy metals and toxic organic compounds. Therefore the success of the dredging process depends on the prevention of resuspension of fine particles. Advanced dredging processes employ pumping the sediment with water onto a ship and release the turbid water pumped with sediment into waterbody after collection of sediment solids. Before release of the turbid water into lake or river, just a few minutes allowed to precipitate the suspended particle due to the limited area on a dredging ship. However the fine particle cannot be removed by the gravitational settling over a few minutes. Environmental technology such as coagulation and precipitation could be applied for the settling of fine particles. However, the process needs coagulants and big settling tanks. For the quick settling of the fine particles suspended during dredging process magnetic separation has been tested in current study. Magnetic force increased the settling velocity and the increased settling process can reduce the volume of settling tank usually located in a ship for dredging. The magnetic assisted settling also decreased the heavy metal release through the turbid water by precipitating highly contaminated particles with magnetic force.

• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.156-159
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• 2010

Peroxide is used frequently to provide electron acceptors to aerobes for the purpose of in situ bioremediation of contaminated soil/sediment. In this study, oxygen release rate of peroxides and factors affecting on dissolution and diffusion of oxygen into pore water were evaluated. Peroxides studied in this study were magnesium peroxide ($MgO_2$), calcium peroxide ($CaO_2$), and sodium percarbonate ($Na_2CO_3{\cdot}1.5H_2O_2$). $Na_2CO_3{\cdot}1.5H_2O_2$ showed the highest oxygen release rate per unit mass and the shortest release duration time among three peroxides. A simple first-order decay model for predicting the release rate of oxygen from peroxide into pore water was presented and used to fit the experimental data. The first order oxygen release rate constants k for $MgO_2$, $CaO_2$ and $Na_2CO_3{\cdot}1.5H_2O_2$ were 0.45 /hr, 3.22 /hr and 134 /hr, respectively. If $MgO_2$ was mixed with clay, oxygen release rate was lowered significantly mainly due to limitation of contact area and diffusion, implying that oxygen can be provided to the indigenous aerobes for the extended period of time.

• Journal of the Korean GEO-environmental Society
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• v.11 no.11
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• pp.63-75
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• 2010

There are several remediation technologies for heavy metal contaminated soils but increasing cost limits the application of the technology if the contaminated area is large. Therefore, stabilization, which blocks the release of heavy metals or makes slow the release, is one of the applicable technology for the heavy metal contaminated soil. Current study is an applicability test for a smelter area with various stabilizer such as magnetite, hematite, zeolite-A, zeolite-X, zeolite-Y, zinc oxide, calcium oxide, carbon trioxide, manganese oxide, manganese dioxide, fish bone, sodium phosphate. The soil contaminated with arsenic, lead, copper, nickel, and zinc could not be stabilized only one stabilizer which is known to have stability for certain metal. Many of the stabilizer works for a few metal but not all of the heavy metal. In several cases, stabilizers increase the release of the other metals while they stabilize some metals. In general, the stabilizing efficiency was increased with time. For Ni, Pb, calcium oxide, carbon trioxide, manganese oxide had good stabilizing effect in water extractable portion. For Cu, manganese oxide, zeolite showed good results especially in the exchangeable portion of the sequential extraction. For As, magnetite had good ability but most of the metal oxide which showed good result for other heavy metals increased with the release of As. Current study suggest that multiple stabilizers are needed for the contaminated soil and dose of the stabilizer and stabilizing time should be carefully considered for the soil contaminated with various metals.

• Maritime Security
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• v.2 no.1
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• pp.125-149
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• 2021

Even 10 years after the Fukushima nuclear disaster, Japan has yet to solve the problems emerging from generating contaminated water every day. Japan has unilaterally decided to release nuclear wastewater in the sea despite Korea's concerns about safety as their radioactive water storage tanks reach the limits. Despite Korea's response, Japan is still preparing to discharge nuclear wastewater without fulfilling its obligations under the United Nations Convention on the Law of the Sea. There are concerns about marine pollution caused by the radioactive materials from nuclear wastewater and invading Korea's maritime sovereignty. In particular, it is impossible to reverse the effects of environmental pollution, so plans to discharge radioactive water must be prevented unless immediate safety is guaranteed. This study proposes Korea's response strategy to resolve the conflict between the two countries due to plans to release contaminated water. Korea should respond to Japan's release of nuclear wastewater in the sea in various ways through cooperation with Japan, provisional measures, and cooperation with neighboring countries.

• 수도
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• s.50
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• pp.20-25
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• 1989

Water quality of river is greatly influenced by sediments of planktons, suspended solids and organic matters being transported by efflenced. The water quality is also affected by their release at the place of sediments with slow flow of water. This paper deals with the Characteristics of Oxygen consumption of sediments in small river which is greatly vary with time. Some typical samples of sediment were taken from both aerobic and anaerobic condition reserved for several months. and, the samples of sediment were checked on the relative ratio of oxygen consumption by nitrification.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.9
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• pp.670-676
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• 2011

Artificially metal-contaminated soils have been widely used for lab-scale soil washing and soil toxicity experiments. The artificial soil contamination methods consist of 1) first equilibrating soils with heavy metal solution, 2) filtrating or centrifuging soils from the mixture and 3) finally drying the soils. However, some of those artificially contaminated soil experiments have not clearly shown that the soils were thoroughly rinsed with water prior to conducting experiments. This study investigated the amount of heavy metal release from the artificially metal-contaminated soil by pre-water-rinsing. Three different artificially metal-contaminated soil preparation methods were first evaluated with Cd and Pb concentrations of soil. Then, this study investigated the effect of pre-water-rinsing on the Cd and Pb concentration of the artificially contaminated soil. Heavy metal concentrations of the soil produced by equilibrating and drying the metal solution-soil were significantly reduced by pre-water-rinsing. The results of the study implied that experimental results would be significantly distorted when the artificially heavy metal-contaminated soils were not thoroughly water-rinsed prior to conducting experiments. Therefore, the initial heavy metal concentration of the artificially contaminated soil should be determined after thoroughly rinsing the soil that was previously obtained through the adsorption and dry stages.

• Journal of Environmental Science International
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• v.30 no.3
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• pp.195-206
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• 2021

Contaminated marine sediment is a secondary pollution source in the coastal areas, which can result in increased nutrients concentrations in the overlying water. We analyzed the nutrients release characteristics into overlying water from sediments and the interaction among benthic circulation of nitrogen, phosphorus, iron, and sulfur were investigated in a preset sediment/water column. Profiles of pH, ORP, sulfur, iron, nitrogen, phosphorus pools were determined in the sediment and three different layers of overlying water. Variety types of sulfur in the sediments plays a significant role on nutrients transfer into overlying water. Dissimilatory nitrate reduction and various sulfur species interaction are predominantly embodied by the enhancing effects of sulfide on nitrogen reduction. Contaminant sediment take on high organic matter, which is decomposed by bacteria, as a result promote bacterial sulfate reduction and generate sulfide in the sediment. The sulfur and iron interactions had also influence on phosphorus cycling and released from sediment into overlying water may ensue over the dissolution of ferric iron intercede by iron-reducing bacteria. The nutrients release rate was calculated followed by release rate equation. The results showed that the sediments released large-scale quantity of ammonium nitrogen and phosphate, which are main inner source of overlying water pollution. A mechanical migration of key nutrients such as ammonia and inorganic phosphate was depicted numerically with Fick's diffusion law, which showed a fair agreement to most of the experimental data.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1999.10a
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• pp.3-6
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• 1999

Several chemical washing procedures were applied to Parathion and Diazinon contaminated soil. Batch and column tests were performed to determine the insecticides extraction efficiency as a function of pH. Washing efficiency of methanol is more higher than that of water and HCl when washed parathion and diazinon are. Those are completely miscible with most organic solvents. For parathion, release trend is increased as pH is increased because it is hydrolyzed easily at the condition of alkali. But diazinon shows reverse because diazinon is decomposed rapidly at the condition of acidic So, diazinon is more released than parathion is because this experiment is peformed in acidic and weak acidic conditions. Generally, parathion and diazinon are classified as having low mobility, so they can be easily controlled if the proper washing process are applied.

• Journal of Soil and Groundwater Environment
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• v.27 no.1
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• pp.60-70
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• 2022

We evaluated the performance of in-situ capping to prevent the release of phenol, one of hazardous chemicals of concern for their impact on sediment. Sediment near the estuary of Hyeongsan River, Korea, and commercially-available sand were collected to evaluate their physical properties and phenol sorption characteristics. Biodegradation kinetics of phenol spiked into the sediment was evaluated under freshwater and estuarine salinity conditions. These experimental measurements were parameterized and used as input parameters for executing CapSim, a software predicting the performance of in-situ capping. The CapSim simulation demonstrated that capping with 50-cm sand reduced the phenol release by several orders of magnitude over 0.25- and 1-year duration for almost all simulation scenarios. The variables tested, i.e., cap thickness, pore-water movement, and biodegradation rate, showed high correlation to each other to influence the extent of phenol release from sediment to the water column. The findings and the framework employed to evaluate the performance of in-situ capping in this study can be adopted to determine whether in-situ capping is appropriate remedial approach at sediment sites impacted by hazardous chemicals due to accidental spills.