• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.197-206
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• 2023

Recently, the international community, including the International Maritime Organization (IMO), has strengthened regulations on air pollution emissions of ships, and eco-friendly ships are actively being developed to reduce exhaust gas emissions. Among them, rotor sail (RS), a wind-assisted ship propulsion system, is attracting attention again. RS is a cylindrical device installed on the ship deck, that generates hydrodynamic lift using a magnus effect. This is a next generation eco-friendly auxiliary propulsion technology, and Enercon company, which developed RS-applied ships, announced that fuel savings of more than 30% are possible. In this study, optimal installation conditions such as RS spacing and arrangement type were selected when multiple RSs were installed on ships. AR=5.1, SR=1.0, and D_e/D was fixed at 2.0 according to the RS arrangement, and the wind direction was considered only for the unidirectional +y-axis. Regarding arrangement conditions, five conditions were set at 3D intervals in the +x-axis direction from 3D to 15D and five conditions in the +y-axis direction from 5D to 25D. C_L, C_D and aerodynamic efficiency (C_L/C_D) were compared according to the square(□) and diamond(◇) shape arrangements. Consequently, the effect of RS on the longitudinal distance was not significantly different. However, in the case of RS flow characteristics according to the transverse distance, the interaction effect of RS was the greatest when the two RSs almost matched the wind direction. In the case of the RS flow characteristics according to the arrangement, notably, when the wind blew in the forward (0°) direction, the diamond (◇) arrangement was least affected by the backward flow between RSs.

• Analytical Science and Technology
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• v.24 no.5
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• pp.395-400
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• 2011

This study has been carried out in order to effectively manage three groups of unregulated hazardous organic substances (PCDD/DFs, PAHs, PCBs) in South Korea. The investigated substances have been analyzed according to the test methods for hazardous substances in specified wastes provided by the National Institute of Environmental Research, Korea. Total contents of the organic compounds have been determined for hazardous wastes from three major industrial categories (paint, iron removal, steelmaking), such as waste organic solvent, waste paint or dust. By investigating the waste samples for 7 PAHs using GC/MSD, Naphthalene has been detected (N.D~1631.33 mg/kg). The highest Naphthalene concentration, which exceeded the korean marine dumping waste standard, was found in waste organic solvents and waste paints. Although a content analysis of 7 PCB isomers has been conducted, none of these compounds was detected. The analysis of PCDD/DFs has revealed that all samples meet the criterion for low POP content defined in the technical guidelines developed under the Basel Convention. The PCDD/DFs content in dust samples deriving from 10 manufacturing processes (billet, bloom) was determined to be in the range of N.D~5.66 ng I-TEQ/g waste.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.7
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• pp.773-778
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• 2015

Global warming has recently become an issue that has resulted in a growing trend to minimize environmental pollution. The International Maritime Organization (IMO) has shown that the majority of marine atmospheric pollution occurs as a result of emissions from marine vessels. Therefore, the environmental regulations and emission standards regarding marine vessels have gradually become stricter, and the research and development in this area is experiencing significant progress. In this study, a nozzle for a fuel oil scrubber was investigated using computational fluid dynamics (CFD) and particle imaging velocimetry (PIV). Experiments were conducted on scaled-down model of the scrubber to determine its performance, which was then compared with CFD results. Based on the experimental results, it was found that at a spray angle of $66^{\circ}$, the spray velocity at the nozzle was 20.1 m/s. From this comparison, a full-scale scrubber model was analyzed using CFD, and the effect of the positioning of the nozzle was studied.

• Journal of Wetlands Research
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• v.22 no.2
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• pp.153-160
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• 2020

Most studies defined microplastic (MP) as plastic particles less than 5 mm. The ubiquity of MP is raising awareness due to its potential risk to humans and the environment. MP can cause harmful effects to humans and living organisms. This paper review aimed to provide a better understanding of the sources, pathways, and impacts of MP in the environment. MP can be classified as primary and secondary in nature. Moreover, microplastic can also be classified as based on its physical and chemical characteristics. Stormwater and wastewater are important pathways of introducing MP in large water bodies. As compared to stormwater, the concentrations of MP in wastewater were relatively lower since wastewater treatment processes can contribute to the removal of MP. In terms of polymer distribution, wastewater contains a wider array of polymer varieties than stormwater runoff. The most common types of polymer found in wastewater and stormwater runoff were polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polyethylene (PE) and polyethylene terephthalate (PET). The continuous discharge and the increasing number of MP in the environment can pose greater hazards and harmful effects on humans and other living organisms. Despite the growing number of publications in relation to MP, further studies are needed to define concrete regulations and management strategies for mitigating the detrimental effects of MP in the environment.

• Journal of Korea Port Economic Association
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• v.30 no.4
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• pp.69-89
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• 2014

The business performance of port industry is steadily getting worse due to international environmental regulation. The port industry should be prepared according to ambient condition change. IMO(International Maritime Organization) is tightening up environmental regulation of vessel and maritime industry field. ECA(Emission Control Area), starting with the Baltic, has initialized and has been expanded. Korea must strengthen the control of vessel in accordance with IMO's restriction, if Korea is designated as emission control area. These situations cause the expansion of LNG-fuelled ships. Add to the larger trend of ships, Korean government should be done a preemptive action against LNG bunkering industry. This study proposes the concept of floating offshore LNG bunkering system and is conducted its economic feasibility evaluation based on empirical analysis. We examine the theoretical foundation and basic information via "A Planning Study on the Engineering Development of Floating Offshore LNG Bunkering Terminal" in 2013 and we evaluate the business potential by using the report above mentioned. The results of this study are as follows. The values of B/C analysis are between 0.679 and 2.516 depending on market share and R&D contributiveness. In case of 10.9%(market share), if market share are 50% and 60%, the value of B/C analysis are 0.697 and 0.837 respectively. Except in two cases, all remaining values are over 1.0. Moreover, the research is conducted sensitivity analysis to remove the project uncertainty. In order to maintain economical validity, a project manager have to establish business strategies which are not to cause increase of expense and sustain market share and R&D contributiveness in the scenario with normal levels.

• Journal of Life Science
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• v.32 no.7
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• pp.578-587
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• 2022

Korea, as the world's 7^th largest emitter of greenhouse gases, has raised the national greenhouse gas reduction target as international regulations have been strengthened. As it is possible to utilize coastal and marine ecosystems as important nature-based solutions (NbS) for implementing climate change mitigation or adaptation plans, the blue carbon ecosystem is now receiving attention. Blue carbon refers to carbon that is deposited and stored for a long period after carbon dioxide (CO₂) is absorbed as biomass by coastal ecosystems or oceanic ecosystems through photosynthesis. Currently, there are only three blue carbon ecosystems officially recognized by the Intergovernmental Panel on Climate Change (IPCC): mangroves, salt marshes, and seagrasses. However, the results of new research on the high CO₂ sequestration and storage capacity of various new blue carbon sinks, such as seaweeds, microalgae, coral reefs, and non-vegetated tidal flats, have been continuously reported to the academic community recently. The possibility of IPCC international accreditation is gradually increasing through scientific verification related to calculations. In this review, the current status and potential value of seaweeds, seagrass fields, and non-vegetated tidal flats, which are sources of blue carbon on the east coast, are discussed. This paper confirms that seaweed resources are the most effective NbS in the East Sea of Korea. In addition, we would like to suggest the direction of research and development (R&D) and utilization so that new blue carbon sinks can obtain international IPCC certification in the near future.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.12
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• pp.1113-1122
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• 2009

In order to find the way to solve the problem of sewage sludge discharge into the ocean, the sludge solubilization by ultrasonic and the improvement methods of wastewater treatment process were studied. In the membrane bioreactor the sludge retention time was stepwise increased from 5.1 day to 442 days where the biomass average concentration has been increased from $c_B$=3.4 $gTSSL^{-1}$ to $c_B$=14.5 $gTSSL^{-1}$ respectively. At the same time, the biomass yield coefficients were reduced from 0.5-0.7 at SRT=5.1 day to 0.005-0.007 at SRT=442 days which means the reduction of sludge production. Oxygen mass transfer coefficients and ${\alpha}$-factor were investigated with changing stirrer speed to find the relation between the high biomass concentration and aeration efficiency in the propeller loop reactor. As a result of sludge solubilization, the solubilization of sludge by ultrasound was increased with increasing energy input and it led to improved anaerobic digestion rate with more biogas production than that of nonsolubilized sewage sludge.

• Journal of Animal Environmental Science
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• v.18 no.2
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• pp.111-122
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• 2012

Establishment of the LFQC (Liquid Fertilizer Quality Certification) system is very urgent issue for recycling livestock manure as renewable resources in Korea faced with environmental problem of manure application to land due to intensive livestock farming. In this study, we investigated relevant laws and regulations on livestock manure fertilizer, certifications of eco-friendly agricultural products, government policies on livestock manure management to establish reasonable direction of Korean LFQC (Liquid Fertilizer Quality Certification) system. As a result from this study, the liquid fertilizers in 'LFQC' system could be classified as three levels according to the usage patterns in field; 1st. Individual Farm Level (IFL), 2nd. Joint Farm Level (JFL), and 3rd. Commercial Level (CML). And finally, we found some characteristics in 'Main Level-Grading Factors' of liquid fertilizer such as fertilizing value, harmfulness, stability, uniformity, economic effect, storage potential, commercial value, functionality. Those items were considered to be the key factors for the establishment of 'LFQC' system. More research on 'Evaluation Standards' for concrete guideline and on the 'Main Level-Grading Factors' be needed to complete Korean LFQC system.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.8
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• pp.574-582
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• 2012

This study presents the concentrations of the polycyclic aromatic hydrocarbons (PAHs) listed as priority pollutants by United States Environmental Protection Agency (US EPA), in 98 sludges from 54 industrial wastewater treatment facilities of South Korea. The mean concentrations of ${\Sigma}_{16}PAHs$ were ranged from 32.5 ${\mu}g/kg-dw$ to 1189.3 ${\mu}g/kg-dw$ by industries, and the highest content was found in the petrochemical industry, followed by chemical, clothing manufacturing and dying, pulp and papermaking, secondary wastewater treatment, and food/beverage producing industries. Comparisons to the EU and Danish standards of ${\Sigma}_{16}PAHs$ in sewage sludge for land application showed only two samples (one from petrochemical, and the other from chemical industry) exceeded the limits. ANOVA test with PAH concentrations as variables revealed no statistically significant influences by industrial types and sampling time (i.e., seasonal variations). Pearson correlations between individual PAHs showed strong relationships (r>0.7) among 4-ring PAHs. Concentrations of acenaphthylene, anthracene, fluoranthene, benzo(a)anthracene, benzo(f)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene presented strong correlations to ${\Sigma}_{16}PAHs$. Principal component analysis discriminated entire samples into three groups by two principal components (PC1 and PC2) with 70% of data variations, in which industrial types were not of importance, but a dominance of certain PAHs. Samples in group-I, which is high PC1 and low PC2, were characterized by a dominance of 2-ring PAHs, and in group-II, PC1 and PC2 showed a linear relation, was dominant 4-ring PAHs. Group-III with low PC1 and high PC2 includes 17 samples showing a noticeably high contribution of 3-ring PAHs to ${\Sigma}_{16}PAHs$. This study provides concentrations of PAHs in industrial sludges collected from a wide variety of sources (six industrial types) and two seasons of sampling events, and the comparison of ${\Sigma}_{16}PAHs$ with other studies are also discussed.