• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.1
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• pp.66-70
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• 2003

Harbor construction works such as dredging, reclamation, riprap dumping and so on generate suspended sediment to affect ocean environment negatively so silt protector is widely used to keep construction site from deteriorating at the moment. This study has a purpose to improve our design techniques by comparing the design procedures of the silt protector between Korea and Japan.

• Proceedings of KOSOMES biannual meeting
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• 2007.05a
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• pp.15-20
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• 2007

In this study, the authors investigated the change of marine environment by dumping dredged materials generated by construction of Busan New Port. There are lots of possibilities to impact an ocean ecosystem by toxic materials in the dredged material dumped in the open seas. As a result of analysis of environmental monitoring in the study areas 12 times a year, COD is II grade, T-N is I grade, T-P is between II and III grade. This result is same as another results of offshore in Korea. It seems unclear that it results from the change of water quality by dumping dredged material. However, according to the result of this investigation, it is not effected extensively to the marine environment by dumping dredged materials. We need further environmental monitoring in the interest sea areas, also need to keep on investigating the impact on the marine ecosystem by dumping dredged materials.

• Proceedings of KOSOMES biannual meeting
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• 2009.06a
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• pp.163-163
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• 2009

• Journal of Environmental Impact Assessment
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• v.18 no.3
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• pp.185-193
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• 2009

This study documented and diagnosed the status and problems of coastal dredging and offshore disposal of dredged sediments in South Korea to improve assessment procedures for marine environmental impacts and develop effective management systems. A total of $729({\times}10^6)m^3$ of coastal sediment was dredged in the harbors during the period of 2001-2008. Most of dredged sediment was disposed to the land dumping sites whereas ocean disposal accounted for less than 5%. Ocean disposal areas were especially concentrated to the exclusive economic zone (EEZ) in the southeast of Busan, which is not only an important fishing area for fishermen, but also considered to be spawning and nursery ground for some commercial fish species. To minimize negative impacts of dredging and ocean disposal of coastal sediment on marine ecosystem and potential strife among coastal users, we suggest 1) in development projects involving ocean disposal, it should be mandatory to propose careful reuse plans in the land, and 2) guidelines of environmental assessment and consequence management programs should be developed and implemented.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.212-223
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• 2022

For the remediation and restoration of contaminated sediment at the West Sea-Byeong dumping site, dredged materials was dumped in 2013, 2014, 2016, and 2017. The physicochemical properties and benthic fauna in surface sediments of the capping area (5 stations) and natural recovery area (2 stations) were analyzed annually from 2014 to 2020 to evaluate the capping effect of the dredged materials. The natural recovery area had a finer sediment with a mean particle size of 5.91-7.64 Φ, while the sediment in the capping area consisted of coarse-grained particles with a mean particle size of 1.47-3.01 Φ owing to the capping effect of dredged materials. Considering that the contents of organic matters (COD, TOC, and TN) and heavy metals in the capping area are approximately 50 % lower (p<0.05) than that in the natural recovery area, it is judged that there is a capping effect of dredged materials. As a result of analyzing macrobenthic assemblages, the number of species and ecological indices of the capping area were significantly lower than that of the natural recovery area (p<0.05). The number of species and ecological indices at the capping area were increased for the first four years after the capping in 2013 and 2014 and then tended to decrease thereafter. It is presumed that opportunistic species, which have rapid growth and short lifetime, appeared dominantly during the initial phase of capping, and the additory capping in 2016 and 2017 caused re-disturbance in the habitat environment. In the natural recovery and capping areas, Azti's Marine Biotic Index (AMBI) was evaluated as a fine healthy status because it maintained the level of 2^nd grades (Good), whereas Benthic Pollution Index (BPI) remained at the 1^st and 2^nd grade. Therefore, capping of dredged materials for remediation of contaminated sediment in the dumping site has the effect of reducing the pollution level. However, in terms of the benthic ecosystem, it is recommended that the recovery trend should be monitored long-term. Additionally, it is necessary to introduce an adaptive management strategy when expanding the project to remediate the contaminated sediment at the dumping area in the future.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.1
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• pp.57-63
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• 2015

Recently, Korea's municipal wastewater treatment plants generated amount of wastewater sludge per day. However, ocean dumping of sewage sludge has been prohibited since 2012 by the London dumping convention and protocol and thus removal or treatment of wastewater sludge from field sites is an important issue on the ground site. The hydrothermal carbonization is one of attractive thermo-chemical method to upgrade sewage sludge to produce solid fuel with benefit method from the use of no chemical catalytic. Hydrothermal carbonization improved that the upgrading fuel properties and increased materials and energy recovery, which is conducted at temperatures ranging from 200 to $350^{\circ}C$ with a reaction time of 30 min. Hydrothermal carbonization increased the heating value though the increase of the carbon and fixed carbon content of solid fuel due to dehydration and decarboxylation reaction. Therefore, after the hydrothermal carbonization, the H/C and O/C ratios decreased because of the chemical conversion. Energy retention efficiency suggest that the optimum temperature of hydrothermal carbonization to produce more energy-rich solid fuel is approximately $200^{\circ}C$.

• Journal of the Korean GEO-environmental Society
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• v.17 no.8
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• pp.5-15
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• 2016

As the increase of domestic sewage treatment plant and reinforcement of the standard of effluent water quality continues, the volumes of sewage sludge are consistently increasing. Existing treatment of sewage sludge, such as incineration and ocean dumping has been prohibited because of air pollution and prohibitions towards ocean dumping, and in turn, recycling and energy recovery from waste methods have being studied recently. However, the lack of technical level and systematic analyses of application technique are problems, that future analysis of such relative technique would be required. The present study has been investigated as follows, management technique of sludge, patent on refuse-derived fuel and increase biogas production and utilizable technology, trend of research paper. Furthermore, research development from five developed nations (Korea, Japan, China, United States, and United Kingdom), domestic and foreign have been investigated and analyzed by section. In this study, the future technical field which is required for effective management of sludge has been suggested.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.135-150
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• 2010

At the Intergovernmental Meeting held in 1972, the London Convention was adopted to prevent marine pollution from dumping of wastes and other matter. After that, at the special meeting held at the Headquarters of the International Maritime Organization in 1996, the London Convention was revised to consider advances in technology of treatment and disposal of wastes and to reflect changes in understanding of marine environment and then the London Protocol was concluded. The London Protocol states more concrete management system for ocean dumping than the London Convention and also provides that the Meeting of Contracting Parties shall establish those procedures and mechanisms necessary to assess and promote compliance with the Protocol. With the London Protocol in force since 24 March 2006, the Meeting of Contracting Parties adopted the 'Compliance Procedures and Mechanisms (CPM) pursuant to Article 11 of the 1996 Protocol to the London Convention 1972' and established the Compliance Group in 2007. According to the CPM, members of the Compliance Group shall be nominated by Contracting Parties, based on equitable and balanced geographic representation of the five Regional Groups of the United Nations, and elected by the Meeting of Contracting Parties. In 2009, the Republic of Korea nominated a member of the Compliance Group to be subsequently elected by the Meeting of Contracting Parties with the approval of other states in Asia Group. Through the United Nations Regional Group System based on geographical identity or political affinity, Contracting Parties to the London Protocol are expected to form a voting bloc or to exchange information in meetings on the London Protocol. In this sense, it is noteworthy that the London Protocol introduced marine environmental management system for comprehensive prohibition of ocean dumping with exception of the so-called 'reverse-list' which had been earlier adopted by the 'Convention for the Protection of the Marine Environment of the North-East Atlantic, 1992 (OSPAR)' whose contracting parties belonged to Western European and Other States Group. In recent years, the jurisdiction of London Protocol has been extended to protect and preserve the marine environment from all sources of pollution. This will make the United Nations Regional Group System play more important roles in the activities associated with the London Protocol. For this reason, this article has considered characteristics of the United Nations Regional Group System and has analyzed influences of this Regional Group System in meetings on the London Protocol. This could provide preliminary information for the Republic of Korea to give due consideration to the United Nations Regional Group System on the activities associated with the London Protocol.

• International Journal of Ocean System Engineering
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• v.3 no.4
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• pp.175-187
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• 2013

Moonpools are vertical wells in a floating body used onboard many types of vessels like Exploration and drilling vessels, Production barges, Cable-laying vessels, Rock dumping vessels, Research and offshore support vessels. Moonpool gives passage to underwater activities for different types of ships as per their mission requirements. It is observed that inside a moonpool considerable relative motions may occur, depending on shape, depth of the moonpool and on the frequency range of the waves to which the ship is exposed. The vessel responses are entirely different in zero and non-zero Froude number. Former situation is paid attention in this study as the mission requirement of the platform is to be in the particular location for long period of operation. It is well known that there are two modes of responses depending on the shape of the moonpool viz., piston mode for square shape and sloshing mode for rectangular shapes with different aspect ratios of opening like 1:1.5 and 1:2 ratios. Circular shaped moonpool is also tested for measuring the responses. The vessel moored using heavy lines are modelled and tested in the wave basin. The pretensions of the lines are varied by altering the touchdown points and the dynamic tensions on the lines are measured. The different modes of oscillations of water column are measured using wave gauge and the vessel response at a particular situation is determined. RAOs calculated for various situations provide better insight to the designer.

• Journal of Ocean Engineering and Technology
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• v.30 no.3
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• pp.177-185
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• 2016

In this study, the model developed by Hong (2012) was modified to describe the consecutive docking/undocking situation and was also applied to investigate the effect on seawater circulation in Busan port by consecutive docking/undocking at the connecting bridge of Busan port. Numerical experiments for various docking/undocking cases were performed by dumping the initial concentration within Busan Port and indicated that the concentration in Busan port becomes steady state without numerical wiggles after sufficient time (at least 20 or 30 days). In addition, it was found that the seawater circulation under ship docking was slightly reduced in comparison with that under ship undocking, and the approach time to the target concentration under all the docking cases increased in comparison with the undocking case.