• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.2
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• pp.83-99
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• 2005

To evaluate environmental charateristics of the South Sea and East China Sea on summer, water and sediment quality were measured in June 2001-2003. Surface layer was affceted by Warm water originated from the high temperature and salinity-Tsushima Warm Current, on the other hand, Yellow Sea Cold Water was spread to the bottom layer in the south-western part of the Jeju island, and salinity at stations near the Yangtze River was decreased below 29psu because of a enormous freshwater discharges. Thermocline-depth was formed at about 10m, and chlorophyll maximum layer was existed in and below the thermocline. COD(Chemical Oxygen Demand), TN(Total Nitrogen), and TP(Total Phosphorus) concentrations showed seawater quality grade II in surface layer of the most area, but concentrations of such as COD, Chl. a, TSS(Total Suspended Solid), and nutrients were greatly increased in the effect area of Yangtze River discharges. Correlations between dissolved inorganic nitrogen, Chl. a and salinity were negative patterns strongly, in contrast, those of inorganic phosphorus, COD and Chl. a were positive, which indicates that phytoplankton biomass and phosphorus are considered as important factors of organic matter distribution and algal growth, respectively. in the study area. The distribution of ignition loss, COD, and $H_2S$ of surface sediment were in the ranges of 2.61-8.81%, $0.64-11.86mgO_2/g-dry$, and ND-0.25 mgS/g-dry, respectively, with relatively high concentration in the eastern part of the study area. Therefore, to effective and sustainable use and management of this area, continuous monitoring and countermeasures about major input sources to the water and sediment, and prediction according to the environmental variation, are necessary.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.12
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• pp.1360-1365
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• 2007

The purpose of this study is to present the basic data for nonpoint pollutant loads from bridge road drainage sediments using the results to analyze organic matter and heavy metals from the four bridge drainage sampling sites with sediments of different particle size ranges. The sediment sample was collected from the bridge road drainage and the masses of nine sediments fractions were obtained after drying the separated sediment in an over at $85^{\circ}C:>2,000{\mu}m$, $1,000\sim2,000{\mu}m$, $850\sim1,000{\mu}m$, $425\sim850{\mu}m$, $212\sim425{\mu}m$, $125\sim212{\mu}m$, $90\sim125{\mu}m$, $75\sim90{\mu}m$, $<75{\mu}m$. The sediment extract was analyzed water quality constituents, including chemical oxygen demand(COD), total nitrogen(T-N), total phosphorus(T-P), heavy metals and particle size distribution. The results indicate that most of particle size ranges of the bridge road sediments was $125\sim425{\mu}m$, and portion of $<75{\mu}m$ was low. But most of the pollutants are associated with the finer fractions of the load sediments. As the results of analysis, the range and average values of COD, T-N, T-P, Fe, Cu, Cr, and Pb were $177\sim198.8$ mg/kg(77.6 mg/kg), $23\sim200$ mg/kg(83 mg/kg), T-P $18\sim215$ mg/kg(129 mg/kg), and $1,508\sim5,612$ mg/kg(3,835 mg/kg), $9.2\sim69.3$ mg/kg(49 mg/kg), $19.1\sim662.2$ mg/kg(214 mg/kg), and $28.4\sim251.4$ mg/kg(114 mg/kg), respectively. The relationship between sediment size and pollutants concentration have an inverse proportion. The removal of road sediments with frequently could be reduced the significant nonpoint pollutant load, because of the bridge road sediment contains considerable micro-particles and heavy metals.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.4
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• pp.315-328
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• 2009

Long-term trends and distribution patterns of water quality were investigated in the Garolim coastal areas of Yellow Sea, Korea from 1998 to 2007. Water samples were collected at 3 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids(SS), chemical oxygen demand(COD), dissolved oxygen(DO) and nutrients. Spatial distribution patterns were not clear among stations but the seasonal variations were distinct except pH and ammonia. The trend analysis by principal component analysis(PCA) during twenty years revealed the significant variations in water quality in the study area. Annual water qualities were clearly classified into 4 clusters by PCA; year cluster 1997, 1998 and 2000-2002, 1999 and 2003-2006/2008. By this multi-variate analysis the annual trends were summarized as follows; In recent years, salinity increased, whereas dissolved inorganic nitrogen, nitrate nitrogen and COD decreased and water quality generally continued to be in good condition in Gsrolim coastal areas without inflow of freshwater from land. Garolim coastal areas are required to be conserved continuously as important coastal areas for fisheries.

• Journal of Environmental Impact Assessment
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• v.24 no.5
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• pp.407-419
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• 2015

The unit load of paddy field was estimated by several methods and compared in this study. Four year field study was conducted at the paddy fields located in Yeongsan river and Sumjin river basins. The unit load was estimated by four methods; (1) averaging field monitored load; (2) NIER (National Institute of Environmental Research) method which use EMC(Event Mean Concentration) and runoff ratio of rainfall groups with rainfall weighting factors; (3)method using EMC determined by best fit probability distribution; (4)method using arithmetic mean EMC and runoff ratio. The result of this study showed that the unit loads of water quality constituents by field monitoring was similar to those of NIER method whereas those by probability distribution(log-normal, gamma) method were less than unit loads of NIER method. The unit loads by arithmetic mean EMC and runoff ratio were larger than those by NIER method. The unit load by NIER method showed higher BOD, COD, SS, lesser T-N, and similar T-P values when compared to unit loads determined by MOE in 1995.

• The Korean Journal of Malacology
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• v.29 no.4
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• pp.291-301
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• 2013

This study researched and compared the sedimentation environment and photosynthetic pigments at Gomso (GS) -bay, Yoja (YJ) -bay and KangJin (KJ) -bay in May, 2012. It was shown that KJ-bay consist of C (clay) and M (mud), and GS-bay consists of Zs (silty sand) and Sz (sandy silt). Averagely, IL of YJ-bay was 4.98%, KJ-bay 6.10%, and GS-bay 1.45%. As for COD concentration, there were no places that exceeded Japanese sediment contamination standard 20 mg/g-dry. As for AVS concentration, in case of KJ-bay, two places exceeded Japanese sediment contamination standard 0.2 mg/g-dry. If we look into the average C/N ratio of bays, YJ-bay showed 8.50, KJ-bay 6.60, and GS-bay 5.52, thus all of them showed the characteristic of oceanic origin. As for the plankton make-up classified by photosynthetic pigments, diatom was dominant, and both ratios of pigment and C/chlorophyll. a showed the relatively lower distribution at GS-bay than at KJ-bay and YJ-bay. It is judged that this is related to the characteristic of flow-in, and it implies that predation process and decomposition by organic matters actively occurs at YJ-bay and KJ-bay.

• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.43-51
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• 2018

In order to systematically and scientifically manage the organic and heavy metals against sediment at Daecheon Port, this study conducted particle composition, organic materials and heavy metals irradiation studies of sediments. Analysis of the grain size composition of sediments in the target study area showed the distribution characteristics of the mix of sand, silt and clay. That is, Station C (Stn. C) showed superior by fine-grained sediment, Station A and B (Stn. A and B) showed superior by coarse-grained sediment. The organic matter(COD, TOC, and IL) of Stn. C was appeared to be heavily polluted more than Stn. A and B. These data for the spatial properties in sediment showed that organic matter was related positively to the sediment silt-clay content. Also, in the case of heavy metals contamination in surface sediments, Stn. C was higher than Stn. A and B. Particularly, at the Stn. C, high organic matter concentration and C/N ratio value( >10) indicated that the sediment was composed highly of land-derived organic matter. From these results, it considered that the correlation analysis among to silt-clay, organic matter and heavy metal was found to have a good interrelationship.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.10a
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• pp.340-345
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• 2003

This study, as a basic study for establishing a influence forecasting/estimating model when drain the deep sea water to the ocean after using it, carried out studies as follows; 1) estimating the amount of river discharge and pollutant loads inflowing into the developing region of deep sea water in East Sea, Korea 2) a field observation of tidal current, vertical distribution of water temperature and salinity, and 3-D numerical experiment of tidal current to analysis physical oceanographic status. The amount of river discharge flowing into the study area was estimated about $462.6{times}10^{3}m^{3}/day$ of daily mean in 2002 year. annual mean pollutant load of COD, TN and TP were estimated 7.02 ton-COD/day, 4.06 ton-TN/day and 0.39 ton/day, respectively. Field observation of tidal current results usually show about $20{\sim}40cm/sec$ of current velocity at the surface layer, it indicated a tendency that the current velocity decreases under 20cm/sec as the water depth increases. We could find a stratification within approximately the depth of 30m in field observation area, and the depth increases. We could find a stratification within approximately the depth of 30m in field observation area, and the differences of water temperature and salinity between the surface layer and bottom layer were about $18^{\circ}C$ and 0.8 psu, respectively. On the other hand, we found that there was a definite as the water mass of deep sea water about 34 psu of salinity.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.4
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• pp.259-268
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• 2003

The damage of water quality like red tide occurs every year inspite of the total load regulation of pollutant inflows from land such as COD, phosphorus and so on around Seto inland sea in Japan. It is attributed to the increase of primary production due to eutrophication. and the rising and settling from the sediment containing nutrient salt. Furthermore, the recent research shows that nutrient salt such as nitrogen and phosphorus, flows into Kii channel from land as well as the Pacific ocean. To investigate the distribution of water quality and flow and residual current in Kitan strait, the field observations were carried out. The field data were obtained a time each season from 1999 to 2002. The results of observations and data of other research institution are used to understand the mechanism of pollution in the strait.

• Journal of fish pathology
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• v.4 no.1
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• pp.15-21
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• 1991

The environmental factors and the distribution of coliform group were investigated in Suyeong bay on the summer, 1989. The ranges of environmental factors were as follows : Dissolved oxygen $0.54{\sim}6.82m{\ell}/{\ell}$, COD(Chemical Oxygen Demand) 0.28~9.84ppm, Salinity 14.7~33.5%, Nitrite $0.13{\sim}20.49{\mu}g-at/{\ell}$, Nitrate $0.89{\sim}62.77{\mu}g-at/{\ell}$, Ammonia $3.81{\sim}246.98{\mu}g-at/{\ell}$, Silicate $6.12{\sim}177.5{\mu}g-at/{\ell}$. The coliform group ranged $10^4{\sim}10^5/100m\ell$ in the mouth and it was decreased in the open sea. Among the composition of coliform group, E. coli I type was dominent at distance area. The correlation between coliform group and ammonia was r=0.629. There were negative correlation between salinity, dissolved oxygen and coliform group during study period.

• Korean Journal of Microbiology
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• v.36 no.4
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• pp.285-291
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• 2000

To investigate the variations of physicochemical factors and microbial populations in seven stations at water region of Gangjin bay, nutritive salts, water temperature, transparency, suspended solid, salinity, COD, DO, pH, heterotrophic bacteria, fungi and fecal coliform were analysed four times from February to October, 1999. Total fecal coliform and heterotrophic bacterial population during investigation periods ranged 16.1~166.0 CFU/ml and $5.0{\times}10^3$~$13.1{\times}10^3$CFU/ml, respectively. Stational mean values of these bacterial population showed higher densities at the inlet of fresh water inflow than those of other stations. When the aspects of abiotic and biotic parameters measured were analyzed, ecosystem of Gangjin bay was regulated by factors such as inflow of fresh water, nutrient salts, salinity and variation of water temperature during four seasons.