• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.27 no.3
• /
• pp.45-56
• /
• 2024

Heavy metals emitted from urban development do not decompose in the soil and remain for long periods, continually impacting the environment. Since the mid-1990s, there has been increasing societal concern in South Korea regarding soil contamination, prompting various legislative revisions to reduce pollution. This study utilizes the Environmental Impact Assessment Support System (EIASS) to investigate projects in the metropolitan area that have exceeded the Ministry of Environment's soil contamination concern levels from 1989 to 2022 and to examine improvements in the environmental impact assessment (EIA) process. The results reveal that the average concentrations of nine contaminants-cadmium (Cd), copper (Cu), arsenic (As), mercury (Hg), lead (Pb), hexavalent chromium (Cr6+), zinc (Zn), nickel (Ni), and fluoride (F)-have all increased over the years. Among these, Zn had the highest relative proportion, with 37.5% of the 40 sites exceeding environmental concern levels. Investigation of 19 specific projects at these exceedance sites showed that only 7 had documented analyses of contamination causes and remediation plans, and just one had contracted additional remediation services, though results from these efforts were found to be lacking. Furthermore, since 2019, a significant proportion of these sites were involved in residential developments, likely due to government initiatives in new city development and extensive housing supply plans. This research emphasizes the importance of public disclosure of the processes and outcomes of remediation efforts on historically contaminated soils prior to project development. It discusses improvements to the EIA by reviewing current legislation and international examples. The findings of this study are expected to heighten public awareness about heavy metal contamination and enhance transparency in soil remediation efforts, contributing to sustainable environmental management and development.

• Ecology and Resilient Infrastructure
• /
• v.11 no.2
• /
• pp.43-54
• /
• 2024

Recently, most of the rivers in Korea are experiencing various problems in dimension and river environment, such as expansion of stable area where disturbance does not occur during flood, increase of excessive trees in river channel, fixation of river channel, reduction of sand bar. When the soil supplied by the flood is deposited in the river, the plant is settled in the formed terrain, and when another disturbance of the scale that does not erode there occurs after the plant is settled, the river gradually grows and the vegetation zone is formed there. In particular, in terms of river management, river forestation and river aggradation are objects that must be managed because they are disadvantageous in terms of flood control by lowering the flow rate and raising the water level. Therefore, in this study, the area of vegetation occupied by the year of sandbar was analyzed in the process of river aggradation in Jang-Hang wetland. In addition, the correlation between the growth of Jang-Hang wetland was analyzed through the analysis of the flow rate and the flooding frequency that directly affect the growth of Jang-Hang wetland. Through this, the management plan of Jang-Hang wetland, which is registered in Ramsar Wetland but has been river forestation and is undergoing river aggradation, was proposed.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.23 no.3
• /
• pp.48-66
• /
• 2024

According to the three amended Laws of the Data Economy and the Data Industry Act of Korea, systems for pseudonymous data integration and Data Safe Zones have been operated separately by selected agencies, eventually causing a burden of use in SMEs, startups, and general users because of complicated and ineffective procedures. An over-stringent pseudonymization policy to prevent data breaches has also compromised data quality. Such trials should be improved to ensure the convenience of use and data quality. This paper proposes a prototype system of the Integrated Data Safe Zone based on redesigned and optimized pseudonymization workflows. Conventional workflows of pseudonymization were redesigned by applying the amended guidelines and selectively revising existing guidelines for business process redesign. The proposed prototype has been shown quantitatively to outperform the conventional one: 6-fold increase in time efficiency, 1.28-fold in cost reduction, and 1.3-fold improvement in data quality.

• Journal of Radiation Industry
• /
• v.18 no.1
• /
• pp.43-52
• /
• 2024

Currently, there are no interim storage facilities and permanent disposal facilities in Korea, so all spent nuclear fuels are temporarily stored. However, the temporary storage facility is approaching saturation, and as a measure to this, the 2nd Basic Plan for the Management of High-Level Radioactive Waste presented an operation plan for dry interim storage facilities and dry temporary storage facilities on the NPP on-site. The dry storage can be operated in various ways, and to select the optimal dry storage method, the reduction of exposure for workers must be considered. Accordingly, it is necessary to develop a worker exposure scenario according to the dry storage method and evaluate and compare the radiological impact for each method. The purpose of this study is to develop an exposure scenario for workers transporting spent nuclear fuel by dry storage method. To this end, first, the operation procedure of the foreign commercial spent nuclear fuel dry storage system was analyzed based on the Final Safety Analysis Report (FSAR). 1) the concrete overpack-based system, 2) the metal overpack-based system, and 3) the vertical storage module-based system were selected for analysis. Factors were assumed that could affect the type of work (working distance, working hours, number of workers, etc.) during transportation work. Finally, the work type of the processes involved in transporting spent nuclear fuel by dry storage method was set, and an exposure scenario was developed accordingly. The concrete overpack method, the metal overpack method, and the vertical storage module method were classified into a total of 31, 9, and 23 processes, respectively. The work distance, work time, and number of workers for each process were set. The product of working hours and number of workers (Man-hour) was set high in the order of concrete overpack method, vertical storage module method, and metal overpack method, and short-range work (10 cm) was most often applied to the concrete overpack method. The results of this study are expected to be used as basic data for performing radiological comparisons of transport workers by dry storage method of spent nuclear fuel.

• Korean Journal of Environmental Agriculture
• /
• v.34 no.2
• /
• pp.91-97
• /
• 2015

BACKGROUND: Earthworms are essential detritus feeders that play a vital role in the process of decomposition of organic matter and soil metabolism. The complex process of partial breakdown of organic matter and mixing with mucous and gut microbial flora in the form of earthworm cast results in the reduction of the toxicity. This study focused on the change of cast amount and pollutant contents before and after the eating of the organic waste and upland soil with the two species of earthworm. METHODS AND RESULTS: The two species of earthworms were compared to the cast production. In the upland soil material, the daily amount of worm's cast was 1.42 g in E. andrei and 0.40 g in A. agrestis. In the organic waste material, the cast of E. andrei was 0.78~0.83 g and the cast of A. agrestis. have not been collected because all earthworms died after the treatment. The heavy metals treated in the upland soil were evaluated the impact of the worm excretion. With the E. andrei, the cast production was decreased 0.1~0.8 times in zinc, 0.2~0.5 times in copper, and 0.1~0.7 times in cadmium compared to the control treatment according to the levels of concentration. With A. agrestis, the cast amount was decreased 0.3~1.1 times in zinc, 0.2~0.3 times in copper, and 0.1~2.1 times in cadmium, respectively. The changes of pollutant contents before and after the eating of the organic wastes with E. andrei were studied. In the treatment of the Alcohol Fermentation Processing Sludge and the Fruit Juice Processing Sludge, heavy metal content of the cast was increased 0.7~53.3% compared to the sludge materials. PAHs contents were decreased 50.1% in the cast of the Alcohol Fermentation Processing Sludge and 36.6% in the cast of the Fruit Juice Processing Sludge, respectively. CONCLUSION: In conclusion, although the A. agrestis was bigger than E. andrei in size and weight, the cast amount of A. agrestis was small. The two species of earthworm was less excretion with high concentration of heavy metals. While the heavy metals such as zinc, copper, and cadmium were considerably accumulated in the cast, the total compounds, PAHs were fairly decomposed. There results would provide us for restoring contaminated soil and cleaning organic wastes.

• Korean Chemical Engineering Research
• /
• v.54 no.5
• /
• pp.653-658
• /
• 2016

Poly(ether-block-amide)(PEBAX$_{(R)}$) resin is a thermoplastic elastomer combining linear chains of hard-rigid polyamide block interspaced soft-flexible polyether block. It was believed that the hard polyamide block provides the mechanical strength and permselectivity, whereas gas transport occurs primarily through the soft polyether block. The objective of this work was to investigate the gas permeation properties of carbon dioxide and methane for PEBAX$^{(R)}$-1657 membrane, and compare with those obtained for other grade of pure PEBAX$^{(R)}$, PEBAX$^{(R)}$-2533 and PEBAX$^{(R)}$ based hybrid membranes. The hybrid membranes based PEBAX$^{(R)}$ were obtained by a sol-gel process using GPTMS ((3-glycidoxypropyl) trimethoxysilane) as the only inorganic precursor. Molecular structure and morphology of membrane were analyzed by $^{29}Si$-NMR, DSC and SEM. PEBAX$_{(R)}$-2533 membrane exhibited higher gas permeability coefficients than PEBAX$^{(R)}$-1657 membrane. This was explained by the increase of chain mobility. In contrast, ideal separation factor of $CO_2/CH_4$ for PEBAX$^{(R)}$-1657 membrane was higher than PEBAX$^{(R)}$-2533 membrane. It was explained by the decrease of diffusion selectivity caused by increase of chain mobility. For PEBAX$^{(R)}$/GPTMS hybrid membrane, gas permeability coefficients were decreased with reaction time. Gas permeability coefficient of $CH_4$ was more significantly decreased than $CO_2$. It can be explained by the reduction of chain mobility caused by the sol-gel process, and strong affinity of PEO segment with $CO_2$. Comparing with pure PEBAX$^{(R)}$-1657 membrane, ideal separation factor of $CO_2/CH_4$ for PEBAX$^{(R)}$/GPTMS hybrid membrane has decreased to 4.5%, and gas permeability coefficient of $CO_2$ has increased 3.5 times.

• Journal of The Korean Association of Information Education
• /
• v.5 no.1
• /
• pp.33-45
• /
• 2001

In order to adapt ourselves to the Informationalization Society of twenty-first century, it is required to have ability to find quickly the necessary information and solve the problem of our own. In the field of school, it should be educated to develop learner's ability that can cope with the Informationalization Society. When a learner can study in such direction, he or she will be able to plan the learning of his own as the subject of education, and develop his ability to solve the problem by collecting and examining various information. It is self-leading learning that can make education like this possible. Through computer, especially Web site, self-directed learning can develop can develop the individuality and creativity of learners. They can collect and utilize autonomously information and knowledge. To do such an education, the program that can work out self-directed learning is needed. Therefore the program I want to develop is to reconstruct the 'figure' part of mathematics in elementary school into five steps by utilizing Web site. In the first step is to learn the concept of various shape. This step enable learners to know what figure is and how it can be utilized in our real life. The second step of dot, line and angle makes it possible that learners can consolidate the foundation of the study about figure and recognize the relation between angle and figure. In the third step of plane figure, we can study how to calculate the relation of plane figures and the area of figure with various shapes by cutting and adding them. The fourth step is about congruence and symmetry. Learners can learn to know the figure in congruence, reduction and enlargement and how it is used in our real life. In the fifth step of solid figure, we can learn the relation among the plane figure, solid figure, the body of revolution, corn and pyramid etc. controling the speed of learning on the basis of his ability. In the process of the program, it is also possible to develop learner's ability of self-leading learning by solving the problem by himself. Because this program is progressed on the Web site, it is possible to learn anytime and anywhere. In addition to it, a learner can learn beyond the grade as well as do the perfect learning by controling the pace of learning on the basis of his ability. In the process of the program, it is also possible to develop learner's ability of self-leading learning by solving the problem by himself.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.12
• /
• pp.1769-1775
• /
• 2016

Aerial parts (leaves and stems) of radish are usually discarded due to the distinct undesirable flavors associated with inappropriate preparations, despite their many health benefits. In this study, we examined the role of extrusion process in the removal of off-flavors and elevation of antioxidant activity in radish (Raphanus sativus L.) leaves and stems. To optimize the extrusion conditions, we changed the barrel temperature (110, 120, and $130^{\circ}C$), screw speed (150, 200, 250, and 300 rpm), and moisture content (20, 25, and 30%). The polyphenol and flavonoid contents significantly increased in extruded radish leaves and stems (ER) under optimum extrusion conditions ($130^{\circ}C$, 250 rpm, and 20%). Under extrusion conditions, we compared off-flavors (as amount of sulfur-containing compound) levels between ER and non-extruded radish leaves and stems (NER) by an electronic nose. A total of six peaks (sulfur-containing compound) were similarly detected in both ER and NER, whereas the ER showed reduced off-flavors. Levels of glucosinolate (${\mu}g/g$), which can be hydrolyzed into off-flavors during mastication or processing, were significantly decreased in the ER. From these results, extrusion processing can be an effective method to increase anti-oxidant activity and removal of off-flavors in radish leaves and stems.

• Korean Journal of Environmental Agriculture
• /
• v.13 no.2
• /
• pp.223-230
• /
• 1994

A practical study on a drying and fermentation system equipped with a stirring machine operated mechanically, of pig manure was conducted to prove the efficiency of and practicability to an ordinary pig farm. The type of the drying bed was a round-shaped (r=3m) concrete structure and the stirring machine was adopted to stir and transfer dried pig manure to the fermentation tank. The dried pig manure was put into a fermentation tank ($V=18m^3$), which was aerated from pipe lines installed at the bottom. While water content of pig manure passing through a drying bed was remarkably reduced than before drying, the drying efficiency of this system decreased in winter. However, the temperature of pig manure piled up in the fermentation room in winter reached over $60^{\circ}C$ and excess water of pig manure was removed during the fermentation process. The reduction rate of water content of pig manure, to which dried pig manure was added as bulking material on the drying bed, was 52.1%, but when dried without bulking material it was only 19.7%. Although the content of $P_2O_5$ of dried pig manure was slightly higher than that of fresh pig manure, progressive changes in chemical composition between fresh and dried pig manure made no great difference. Among the contents of minerals of fresh and dried pig manure, CaO was the highest and the rest were in the decreasing order of $K_2O$, MgO, and $Na_2O$. Population density of E. coli and Streptococci of dried pig manure was reduced by 142 and 236 times that of fresh pig manure, respectively. The installation cost of this drying and fermentation system was 4,185,630 won (approximately 5,232 US $) and operating cost per year was 190,000 won (237.5US $) on the basis of self-labor condition.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.1
• /
• pp.42-47
• /
• 2006

The biological nutrient treatment is formed with repetition and rearrangement of anaerobic, anoxic and oxic tank. In this case, VFAs is generated in the anaerobic tank and the anoxic tank. The VFAs is an important factor for removal of nitrogen and phosphate and SVI. So, in this study I investigated to find a relationship among the generation rate of the VFAs according to the change of F/M ratio and the characteristic which can eliminate organic matter and nitrogen according to the change of residual concentration of the VFAs and the efficiency of the process and also SVI in wastewater treatment. $A^2/O$ process was used for wastewater treatment. F/M ratio was under the control of the change of MLSS concentration. When the F/M ratio was changed from 0.16 to 0.08 kg-BOD/kg-MLSS/day, the VFAs's production volume increased based on the reduction of F/M ratio in batch reaction. And the residual concentration of the VFAs decreased at first and then increased later. SVI and SS were high when F/M ratio was $0.16kg/kg{\cdot}d$ and showed stable status when F/M ratio decreased $0.11{\sim}0.13kg/kg{\cdot}d$. However, SVI and SS continuously increased with decrease of F/M ratio and were high at $0.08kg/kg{\cdot}d$. In the result of comparison between residual concentration of the VFAs and denitrification rate in anoxic tank, the less residual volume of the VFAs was in anoxic tank, the higher denitrification ratio became. The optimal residual-concentration of the VFAs considering SVI and removal efficiency of nitrogenwas $1.4{\sim}2.2mg/L$. At that time F/M ratio was $0.11{\sim}0.13$ kg-BOD/kg-MLSS/day.