• Parasites, Hosts and Diseases
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• v.26 no.4
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• pp.275-284
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• 1988

This study was performed to observe the present status of intestinal parasitic infections in a remote island, Yondo, located in southern part of Jeonranam-do (Province) , Korea. In February and May, 1988, total 1,011 individual stool samples were collected and examined for intestinal helminths and protozoa using formalin-ether centrifugal sedimentation technique. The results are summarized as follows: 1. Of 1,011 inhabitants examined, 398(39.4%) were positive for intestinal parasites. Helminth positives were 372(36.8%) , and protozoan cyst positives were 56(5.5%) . 2. Ten species of parasites were found. Trichuris trichiura revealed the highest infection rate of 27.5%, Ascaris lumbricoides 17.4%, Taenia sp. 5.8%, Entamoeba coli 3.3%, Ciardia Zamblia 1.5%, Endelimax nasa 0.8%, Hymenolepis nana 0.4%, Hookworm 0.2%, Trichostrongylus orientalis 0,2%, and Entamoeba histolytica 0.2%, respectively. 3. The female group showed higher positive rate(44.0%) than males (34.7%). Also, higher positive rates were observed among adults as compared with the group younger than 10 years old. 4. Average value of E.P.G. was 1,876(range 200∼17,800) in A. lumbricoides positives, and 327 (range 200∼1,600) in T. trichiura positive cases. 5. In helminth egg Positive cases, single in(traction was 63.4%, double infection 34.7%, and triple infection 1.9%, respectively. Among protozoan cyst positives, single infection was 94.6%, and double infection was 5.4%. The present study revealed that the prevalence of intestinal parasites among inhabitants in Yondo island is still so high that special control measures should be performed.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.198-205
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• 2010

The purpose of this study is to investigate the characteristics of the grain size distribution and organic matters to understand the current status of the tidal flat sediment for efficient management of Suncheon Bay. We investigated the characteristics of the surface sediments in the mouth area of the Suncheon Bay at fifteen stations in April and July, 2009. Specific conclusions were as follows. The sediments in the most part of tidal flat was shown as muddy facies(clay and silt contents was more than 90%), whereas in the tidal river affected by water flow from the Dongstream was shown as sandy facies. The analyzed values of the tidal flat sediment were in the range of $1.9{\sim}3.8{\phi}$(mean $2.5{\phi}$) for sorting, and -1.5~3.2(mean -0.3) for skewness, and 1.5~14.1(mean 3.9) for kurtosis. So we knew that the tidal flat sediments in the Suncheon Bay was mainly composed by fine-grained sediment. Erosion was happened in the tidal river, whereas sedimentation was occurred in the tidal flat. The most of organic matters was derived from the Dongstream. Total organic matters shown as ignition loss was 5.75%, COD and $H_2S$ values were lower than the eutrophication level(COD; 20.0 mg/g dry, $H_2S$; 0.2 mg S/g dry). From our research the tidal flat of the Suncheon Bay is relatively fine, but a part of the flat was exceed the environmental standard. So we have to establish effective countermeasures to reduce the organic matters and nutrients derived from stream for environmental preservation of the Suncheon bay and conduct scientifically sustainable monitering for streams flowing into Suncheon Bay and tidal flat.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.3341-3352
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• 2011

In this study, characteristics of wastewater treatment of sewage intermittently mixed with industrial wastewater is examined by investigating the operational status of each unit operation and measuring water quality. The bioreactor operating condition was measured for MLSS concentration 2,000~3,000 mg/L, HRT 5.3~16.3 hour, SRT 2.8~66.6 day, and SVI frequently showed the value above 200 which was higher than the optimal range of 50~150. It is thought that the sludge is not in suitable condition for sedimentation caused by the incoming industrial wastewater. When industrial wastewater is come into the system, MLDO inside of bioreactor rapidly increased, rate of nitrification is steeply decreased, and Pin floc. is spilled in the secondary clarifier. In the observance of microorganism showed that various bacterial floc. and ciliata were found as well as actinomycetes and filamentous bacteria(Sphaeotilus) which is known to cause bulking. Efficiency of each unit operation was fairly good in average. However, efficiency of the bioreactor treatment showed high fluctuation by unstable operating condition by intermittently incoming industrial wastewater.

• Journal of The Geomorphological Association of Korea
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• v.19 no.4
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• pp.59-71
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• 2012

This research was carried out to analyze long-term shoreline change on Busan Songjeong Beach using multi-temporal remote sensed data, GPS survey data and grain size analysis. As a result of multi-temporal satellite imagery analysis, the beach was stable status till early 2000s, but the erosion occurred over whole beach after the construction of shore protection road since 2000. In the result of DEM analysis, the elevation of beach reduced and the slope of berm increased after construction of shore protection road along the coast, this means the erosion environment was dominant on the beach. But the sedimentation was slightly stronger than the erosion in northern region of the beach, then the slope of berm was gentle. In the result of grain size analysis using in-situ samples, the coarsening-trend was found in southeastern region (Line E) of the beach, it is caused by strong wave energy from the outer sea. Consequently, major causes of the beach erosion in the study area were the interception of sand supply from a dune owing to shore protection road construction and scouring phenomenon by strong wave energy in southeastern region of the beach. If the topographic or artificial change will not occur in the future, the erosion in this area will continue. Therefore the prevention measures are required.

• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.29-45
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• 2017

This study explored spatiotemporal variability of water quality in correspondence with hydro-meteorological factors in the four stations of Euiam Reservoir located in the upstream region of the North-Han River from May 2012 to December 2015. Seasonal effect was apparent in the variation of water temperature, DO, electric conductivity and TSS during the study period. Stratification in the water column was observed in the near dam site every year and vanished between August and October. Increase of nitrogen nutrients was observed when inflowing discharge was low, while phosphorus increase was distinct both during the early season with increase of inflowing discharge and the period of severe draught persistent. Duration persisting high concentration of Chl-a (>$25mg\;m^{-3}$: the eutrophic status criterion, OECD, 1982) was 1~2 months of the whole year in 2014~2015, while it was almost 4 months in 2013. Water quality of Euiam Reservoir appeared to be affected basically by geomorphology and source of pollutants, such as longitudinally linked instream islands and Aggregate Island, inflowing urban stream, and wastewater treatment plant discharge. While inflowing discharge from the dams upstream and outflow pattern causing water level change seem to largely govern the variability of water quality in this particular system. In the process of spatiotemporal water quality change, factors related to climate (e.g. flood, typhoon, abruptly high rainfall, scorching heat of summer), hydrology (amount of flow and water level) might be attributed to water pulse, dilution, backflow, uptake, and sedimentation. This study showed that change of water quality in Euiam Reservoir was very dynamic and suggested that its effect could be delivered to downstream (Cheongpyeong and Paldang Reservoirs) through year-round discharge for hydropower generation.