• Journal of Life Science
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• v.15 no.5 s.72
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• pp.696-702
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• 2005

Ozonation is a disinfection technique of harmful mi-crobes commonly used in the treatment of drinking water. And Biological Activated Carbon (BAC) treatment also provides numerous benefits for drinking water utilities, including removal of micro- pollutants, improved treatment processes. The multiful-stage ozonation and BAC play roles as effective methods for removing several materials in raw water. Water quality variation in Nak dong river and the removal efficiency of viruses by ozonation-BAC process were investigated on pilot scale. During the period of survey, most of water quality parameters including $NH_{4}^{+}-N$ were highly improved after passing through the BAC. The removal efficiency of poliovirus type III in water treatment process using pilot-plant,$ 99.6\% $ of viruses were removed by pre-ozonation, sedimentation and sand filteration process, $ 100\% $ were removed after in BAC filteration step. In the removal survey of viruses by ozonation, ap-proximately $ 61.1\% $ or polioviruses were inactivated by ozone of 0.4 mg/l within 5 min. and $ 100\% $ were inactivated by ozone of 0.8 mg/l over 10 min.

• Journal of Navigation and Port Research
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• v.40 no.6
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• pp.401-412
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• 2016

The sustainable operation and development of ports is a key industry for Korea's national economy. It is increasingly more important to resolve conflicts with local communities due to port environmental problems such as air pollution, water pollution, noise and ecosystem destruction while securing port competitiveness through infrastructure expansion. In case of the Busan New Port development project in Korea, construction has been temporally suspended due to conflict with local fishermen over marine sand mining for construction. A primary reason for this is the absence and limitation of qualitative port environmental impact assessment methodologies in Korea. This includes the current investigation of fisheries damaged by ports. Therefore, the main purpose of this study is to propose economic valuation methods for assessing environmental impacts that are essential for efficient port environmental management and for sustainable port operation and development in Korea. To do this, this study examines the overall port environmental problems and their effects (damages) through the analysis of environmental policies and case studies of domestic and overseas ports. Then economic valuation methods are suggested for total economic values (TEV) of damaged environmental goods and services. Among the proposed methods, Habitat Equivalency Analysis (HEA), as a more scientific data based method, was applied to estimate marine ecosystem service damages from the designation of Busan New Port Anchorages. Finally, based on the study results, more efficient port environmental management will be achieved through the institutional adoption of the proposed economic impact assessment methods for port environmental damages.

• Journal of Soil and Groundwater Environment
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• v.18 no.1
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• pp.57-66
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• 2013

Although the quantity of dredged soils has increased owing to recent new harbor construction, sea course management, polluted sediment dredging, and four-river project, the reuse or recycling of those dredged soils has not done properly in Korea. To develop measures to utilize them in various ways for reuse or recycling, the biophysicochemical properties of dredged soils and sediment were assessed in this study. Samples were classified according to their sources-river and sea-by location, and as dredged soil and sediment depending on storage time. The results showed that dredged materials from the sea have high clay content and can be used for making bricks, tiles, and lightweight backfill materials, while dredged materials from the river have high sand content and can be used in sand aggregates. Separation procedures, depending on the intended application, should be carried out because all dredged materials are poorly sorted. All dredged soils and sediments have high salinity, and hence, salts should be removed before use for cultivation. Since dredged materials from the sea have adequate concentrations of nutrients, except phosphate, they can be used for creating and restoring coastal habitats without carrying out any additional removal processes. The high overall microbial activities in dredged materials from the river suggested that active degradation of organic matter, circulation of nutrients, and provision of nutrients may occur if these dredged materials are used for cultivation purpose.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.631-642
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• 2010

This study is experimentally investigated for the characteristics of compression and tensile of lightweight air-trapped soils with uniform quality. Previously, EPS blocks are often used as lightweight embankment, but many problems such as the level difference and cracks caused by plastic(creep) deformation occurred in the EPS blocks. So, a new material development is urgent. By means of alternatives, lightweight air-mixed soil using in-situ soils has been developed and applied to fields. In comparison with EPS block, lightweight air-mixed soil have less creep deformation in long-time, but the strength characteristics of them are different depending on soils where they are obtained. Therefore, the quality management of them is very difficult. In this study, therefore, characteristics of lightweight air-trapped soil samples are investigated. To do this, the lightweight air-trapped soils are prepared using a manufactured sand with uniform quality. To found out the compression and tensile characteristics of lightweight air-tapped soils, unconfined compression test and splitting tensile test are conducted on the specimens prepared with different unit weight, cement-sand ratio and air-pore.

• Journal of the Korean Geosynthetics Society
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• v.22 no.3
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• pp.61-69
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• 2023

As global trade and maritime port environments change, the need to respond to larger and faster ships is increasing. Accordingly, new ports are being built around metropolitan cities such as Busan and Ulsan. In general, a compaction method using sand or gravel is applied to the construction of a new port. However, due to the lack of sand or gravel and the difficulty in securing economic feasibility due to the increase in unit price, the deep mixing method has recently been used. Therefore, in this study, CMD-SOIL using circulating resources was applied to the Ulsan area, and the applicability was determined by analyzing the laboratory mixing test and boring results at in-situ. As a result of the test, it was analyzed that it showed more than the design mixing strength, and it was possible to secure the similar performance as blast furnace slag cement. In addition, it was analyzed that the design standard strength can be sufficiently secured as a result of in-situ boring. Therefore, considering the field applicability in the Ulsan, it is judged that the use of CMD-SOIL is possible.

• Journal of Ocean Engineering and Technology
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• v.29 no.1
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• pp.62-69
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• 2015

Coastlines are protected by breakwater structures against the erosion of sand or other materials along beaches due to wave action. This research examined the use of physical modeling to determine the effects of the tetrapod size and vertical walls of a rubble mound on the volume of wave overtopping under irregular wave conditions in coastal areas in Busan Yacht Harbor. In this analysis model, the structures were studied using irregular waves and the JONSWAP wave energy spectrum. To understand the effects of the tetrapod size and heights of the vertical wall, the study considered vertical walls of 0, 1.78, 6.83, and 9.33 cm with armor double layered material tetrapods of 8, 12, 16, and 20 tons. An extensive number of experiments covering a relatively large range of variables enabled a comprehensive discussion. First, in the presence of a short vertical wall, the water level played a key role in the overtopping discharge. In such circumstances, the values of the wave overtopping discharge decreased with increasing freeboard size. In the presence of a tall freeboard and middle, the value of the wave overtopping discharge was equally influenced by the vertical wall factor. Moreover, the tetrapod size decreased by an increase in the vertical wall factor, and relationship between them resulted in a short wall height. From an engineering point of view, considering a small water level may allow the choice of a shorter vertical wall, which would ultimately provide a more economical design.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.730-737
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• 2006

High performance liquid chromatographic methods for the simultaneous determination of 12 biogenic amines were developed and contents of biogenic amines in 23 varieties of Korean commercial fermented food were analyzed. Dansyl derivatives of biogenic amine were very stable and had good peak resolution. Except agmatine, the recovery of biogenic amines from soybean paste with extraction of 0.1 N HC1 added biogenic amines to soybean paste was greater 85%. The calibration curve showed good linearity over a concentration range up to 50 ${\mu}g/mL$. In the determination of biogenic amine level in Korean commercial fermented foods, doenjang and chungkukjang (fermented soybean pastes), soy sauce, anchovy and pacific sand lance liquid jeotkal (fermented fish sauce products), and cabbage kimchi had high level biogenic amines. Especially, traditional doenjang had a histamine (HIS) level of 952.0 mg/kg, a tyramine (TYR) level of 1,430.7 mg/kg. Most cheese had low level of biogenic amines, but one Gouda cheese had a tyramine (TYR) level of 97.5 mg/kg. A low level of biogenic amines was detected in wines, beer, yoghurt, and sausage. Putrescine (PUT), cadaverine (CAD), tryptamine (TRY), histamine (HIS), tyramine (TYR), and 2-phenylethylamine (PHE) were mainly formed in fermented foods by the action of microorganism, so their levels were high with a range. On the other hand, spermidine (SPD), spermine(SPM), serotonin (SER), noradrenaline (NOR), and dopamine (DOP) were formed originally via biosynthesis with consequent low level.

• The Korean Journal of Ecology
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• v.28 no.4
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• pp.199-206
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• 2005

Estuary islets should be managed systematically because they are important places for birds to rest and breed. This paper investigates the environmental properties of islets where the sand banks are located from east to west on the southernmost of Nakdong estuary during a year (September 2003 $\sim$ August 2004). The research showed that 59 species and 19,148 individuals were found in the area A (Jangja Shinja-Do) and 61 species and 28,394 individuals in the area B (Saja-Do; Beakhapdeung Doyodeung). Totally, 74 species and 47,539 individuals were observed in both of this estuary. Shorebirds are the most observed species in both areas. In area, most of individuals were especially observed in the spring when Shorebirds migrate northward for breeding. In B area, various species were also observed in the fall when they migrate southward for wintering. Therefore, many groups of birds are observed around Shinja-Do in the spring. They passed the winter in Doyodueng, associated with feeding in the main stream of Nakdong river mainly. Although the southernmost sand bar is the breeding place to access to outside without interception, invasion by human beings and predators (mice, weasels and etc.) gives a fatal blow for birds to breed or rest. The reed which is a tall herbaceous plant is flourished according to the process of ecological succession. Therefore, the sand bar becomes a land. It results in reduction of habitats and breeding grounds for birds. In conclusion, these areas where birds can use the islets as habits and breeding places must be preserved by restraining luxuriance of reeds and systematic management of human beings and predators is necessary.

• Journal of the Korean Geotechnical Society
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• v.25 no.10
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• pp.99-110
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• 2009

In order to provide the design criteria, the characteristics of consolidation for soft ground improvement have been investigated using the field banking test performed by the vertical drain method at the northern container section in Busan New Port. Field test results indicated that the estimated degree of consolidation in design stage decreased by about 7% compared with the measured one. This difference is attributed to the fact that the conservative geological properties were applied with relatively high amount of maximum clay mixture ratio during the design stage. Based on this findings, another laboratory oedometer test was implemented to consider various combination of mixture ratio. It was found that the consolidation degree increased in accordance with the increase of sand/silt mixture ratio. Also, the proportion of 10%, 50%, and 40% for sand, silt, and clay, respectively, was observed as the best combination of mixture ratio to the actual measurement, which is very similar to the average grain size distribution in the banking test area. Therefore, it is suggested that the overall geological characteristics as well as the grain size distribution should be considered in design stage to improve the soft ground that contains mixture of sand, silt, and clay.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.4
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• pp.441-451
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• 2014

The flushing is important to maintain good water quality in water main. It is a technique of using water velocity to remove sediments in water distribution system. The variety of water quality problems can occur in a distribution system, so too can a variety of benefits be gained by system flushing. In order to effectively perform the flushing, the contaminants to be removed to set up and it can be solved, it is necessary to ensure the proper flow rate. In this study, the removal of contaminants present in the inner water pipe attached loose deposits such as fine particles of granular activated carbon, sand and iron corrosion product sought to derive flow rates. Thus, the constant observation of using pilot plant scale water distribution plant for the movement of floating characteristics of particles were assessed.