• Journal of Korea Water Resources Association
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• v.48 no.2
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• pp.79-90
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• 2015

In this study, the water quality parameters of Geum-river were estimated using Landsat 8 satellite image data which had launched in March 2013. The goal of this research is to predict HAB and to monitor spatial pattern of total nitrogen (TN) and total phosphorus (TP) because both TN and TP are the dominant factors of the growth of harmful algal blooms (HABs). To investigate the relationship between satellite band reflectance and in situ measurement value, Pearson' correlation coefficient analysis was used. The band2, 3, 4 and 5 reflectance values among 11 bands of Landsat 8 were used which was highly associated with detecting TN and TP. The 20 in situ data set with satellite's overpass time were identified. TN showed positive relation with band 2 (0.48), band3 (0.62), band4 (0.57) at a significance level of p<0.05. TP also showed high correlation for band2 (0.59), band3 (0.59), band4 (0.58) at a significance level of p<0.01. The optimal regression equation models were constructed for TN and TP based on multiple regression equations. The estimated concentration based on derived regression equations of TN and TP were compared with in situ measurement data. Finally, the spatial pattern of the two parameters was able be monitored through mapping on November 12, 2013 and April 21, 2014.

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.590-594
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• 2005

In this study, the wastewater treatment was conducted to evaluate the removal efficiency of total nitrogen from synthetic wastewater in the F-STEP PROCESS $(anaerobic{\rightarrow}\;oxic\;{\rightarrow}\;anoxic)$ with loess ball as support metrics. The average removal efficiencies of total nitrogen and ammonia nitrogen were $83.0\%\;and\;84.4\%$, respectively. The average nitrification efficiency at the oxic area was $60.9\%$ in the pH range of effluent water between 4.8 and 6.0. On the other hand, in the case of pH range of effluent water between 6.5 and 7.5, the denitrification efficiency at the anoxic area was $96.3\%$. The average concentration of COD was 12.8 ppm and the removal efficiency of COD in the F-STEP PROCESS were $96.3\%$. In the case of SS, the average concentration was $7.0\%$ at the effluent.

• The Korean Journal of Ecology
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• v.27 no.6 s.122
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• pp.375-381
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• 2004

We investigate the biological treatment of processed-leachate from SUDOKWON landfill site in Korea by the reed (Phragmites australis)-bed with a continuous flow system. The reed individuals showing superior growth in processed-leachate experiment were selected among the reeds of thirteen natural habitats by means of the comparisons between the removal rates of nutrient salts, eco-physiological responses and growth. The reed-beds (combination of the reed individuals showing superior growth with helper microorganisms) were continuously supplied with processed-leachate. We monitored the effluents that passing through the reed-beds during the experiment period. After five weeks, analysis results of effluent from each reed-bed were as follows; chromaticity, total nitrogen, total phosphorus, biological oxygen demand, chemical oxygen demand, total dissolved solid and salinity decreased $29.5{\sim}36.9\%,\;49.4{\sim}67.2\%,\;42.1{\sim}94.6\%,\;74.5{\sim}88.8\%,\;15.6{\sim}20.8\%,\;17.5{\sim}35.4\%\;and\;15.3{\sim}34.7\%$, respectively. These results represented the substantial improvement of water-quality after passing through reed-bed in a continuous flow system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7761-7772
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• 2015

This study describes the spatio-temporal distributions in phytoplankton community such as species composition, standing crops and dominant species from April to November 2008 in the Jeju Marine Ranching Area (JMRA). A total of 106 species of phytoplankton belonging to 63 genera was identified. In particular, diatoms and dinoflagellates were occupied more than 61% and 35% of total species, respectively. The annual dominant species were Skeletonema costatum-like species(ls) in April, Torodinium teredo, Cylindrotheca closterium, Scrippsiella trochoidea in June, S. costatum - ls, Thalassionema nitzschioides, Pseudo-nitzschia pungens, Ebria tripartita in September and Corethron pennatum, Dictyocha fibura, Neoceratium teres in November. Phytoplankton cell density ranged between $0.6cells{\cdot}mL^{-1}$ in June and $64.0cells{\cdot}mL^{-1}$ in April. It fluctuated with an annual mean of $11.7cells{\cdot}mL^{-1}$ between the lowest value of $0.9cells{\cdot}mL^{-1}$ in November and the highest value of $37.0cells{\cdot}mL^{-1}$ by S. costatum -ls in April. Diversity index in September was higher than diatom blooming seasons in April. According to the phytoplankton community structure, the biological oceanographic characteristics of the JMRA was characterized by nanoplankton during a year. That is, primary production is deemed to have a higher possibility of being adjusted by a reproduction by material cycle in the ecosystems than nutrients supply from the lands.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.5
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• pp.548-555
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• 2007

The control of wastewater treatment has two merits; one is to regulate water quality of effluent and the other is to reduce the cost of wastewater treatment. The purpose of this study was to control the ammonium nitrogen in effluent that is known to cause eutrophication. The control was based on simplified ASM No. 1 which had 3 component materials and 8 coefficients, and the control method was as following. Firstly the ammonium concentration of inflow was measured and the optimal aeration time in effluent was determined according to simplified ASM No. 1 to be 1.0 mg/L. If ammonium concentration of effluent was not equal to 1.0 mg/L, the influent ammonium was corrected by adaptive control. These processes above were repeatedly performed. The SBR running aerobic-anoxic phase had been controlled for 1 month with this method. As a result, the ammonium concentration of the effluent showed in the range of $0.22\sim3.1$ mg/L with an average concentration of 1.1 mg/L. The adaptive control method used in this study was found very useful to control and predict the effluent concentration of ammonium.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.568-577
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• 2002

The spreading Cocuoainim polykikoides bloom in the southern coastal waters of Korea was simulated using numerical model including the physical processes of water flow and the chemical processes of increasing cell of C. polykikoides by uptake of dissolved nutrients. The circulation of sea water was simulated by two dimensional tide model reflecting the main four tidal components of $M_2,\;S_2,\;K_1,\;O_1$, and permanent current was driven by inflow/outflow across open boundaries. According to the result of model which tidal and permanent current were reflected simultaneously, eastward flows entering the southern waters from the western waters of Korea are dominant but westward flows are weak relatively. These result suggest that it is difficult for initial C. polykikoides bloom generated in the coastal waters of Goheung to move to the western coast of Korea through Jeju Strait. For spreading model of C. poiyhikoides, the range of generating distribution and the generating time of C. polykikoides bloom in coastal area are similar to those of observation data in the field. Wind is the most important factor in moving and distribution of red tide. Permanent current flowing eastward is also considered to be important factor and tidal current was a little influenced.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.506-510
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• 2013

This study aimed to understand relationship between potential risky species and environmental factors at ports in Korea. During the study periods, 25 potential risky species (red tide and toxic species) representing 20 red-tide species, 5 toxic species were observed in the all ports. Skeletonema costatum (red-tide species) was predominated in all study area. This species showed positive correlation with pH, while negative correlation with dissolved oxygen (p<0.05) at Busan port. Also, this species showed positive correlation with total suspended solids and pH (p<0.05) at Ulsan port. However, Sk. costatum showed positive correlation with nitrate at Incheon port (p<0.01). Pseudo-nitzschia spp. producing amnesic shellfish poison (domoic acid) showed positive correlation with nitrate and silicate in all study areas (p<0.05). Alexandrium spp. (paralytic shellfish poison) and Dinophysis acuminata (diarrhetic shellfish poison) were affected by chemical oxygen demand (p<0.01). Our results indicated that red-tide species were affected by physical factors, while chemical factors affected toxic species.

• Journal of Wetlands Research
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• v.15 no.3
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• pp.407-412
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• 2013

The aim of this study was to develop a tree box filter system, an example of Low Impact Development technology, for treating stormwater runoff from road. Monitoring of storm events was performed between June 2011 and November 2012 to evaluate the system performance during wet day. Based on the results, all runoff volume generated by rainfall less than 2 mm was stored in the system. The minimum volume reduction of 20% was observed in the system for rainfall greater than 20 mm. The greatest removal efficiency was exhibited by the system for total heavy metals ranging from 70 to 73% while satisfactory removal efficiency was exhibited by the system for particulate matters, organic matters and nutrients ranging from 60 to 68%. The system showed greater pollutant removal efficiency of 67 to 83% for rainfall less than 10 mm compared to rainfall greater than 10 mm which has 39 to 75% pollutant removal efficiency. The system exhibited less pollutant reduction for rainfall greater than 10 mm due to the decreased retention capacity of the system for increased rainfall. Overall, the system has proved to be an option for stormwater management that can be recommended for on-site application. Similar system may be designed based on several factors such as rainfall depth, facility size and pollutant removal efficiency.

• Journal of Korean Society on Water Environment
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• v.32 no.2
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• pp.142-148
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• 2016

The characterization of stormwater runoff from mix land-use catchments with an inadequate sewer network is a challenge. This study focused on characterizing stormwater runoff from the Paldang watershed area based on land-use type and sewer system coverage. A total of 76 sites were monitored during wet weather from seven different counties within Paldang watershed. Public sewer system (PSS) was installed at 48 sites, while 28 sites had no or individual sewer system (ISS) coverage. The results indicated that the sites included in the ISS group with higher forest and paddy land-use percentage exhibit higher values of average event mean concentrations (EMCs) and first flush intensity for suspended solids (SS), total nitrogen (TN), and total phosphorous (TP). In addition, upgrading runoff interception system can capture 59 % of the TP load in the first 43% of runoff within these sites. Similarly, rainfall depth and storm duration showed a positive correlation (R > 0.6) with nutrient loads within ISS group sites, as compared to PSS group. Therefore, these sites are likely to contribute higher TP and TN loads during heavier storm events and should be selected as priority management areas to combat the problem of eutrophication in Paldang reservoir.

• Journal of Korean Society on Water Environment
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• v.34 no.4
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• pp.423-430
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• 2018

Insomuch as it is important to manage water quality, from the perspective of water management, it is essential to understand the effect of the weirs on water quality and phytoplankton dynamics in various regions. The purpose of this study is to investigate the characteristics of nitro-nutrients, as well as occurrences and succession patterns of phytoplankton, in the river sections of the two weirs in the Yeongsan River for the five years (from 2012 to 2016) after the weir construction. In respect to this data, the average water temperature measured at the representative point in the section of the Seungchon Weir ($17.1^{\circ}C$) was higher than that of the Juksan Weir ($16.6^{\circ}C$) by comparison. By way of an analysis of this data, it was found that the water quality variables such as, organic matter, nitrogen nutrients and phosphorus nutrients were improved gradually during the period, but the degree of the improvement differs as noted and measured between the weirs. Under the circumstances, it is especially noted that the $NH_3-N$ concentration was higher for the point of the Seungchon Weir (2.204 mg/L) than that of the Juksan Weir (1.157 mg/L). This indicates that effluent as seen from sewage treatment plants and hydrological feature near the densely population area, could be the main cause for the incidence of water pollution in the upstream section of the Seungchon Weir. Additionally, the phytoplankton analysis showed that a relative abundance of diatoms and green algae were 56.9 % and 25.8 % respectively. However, it is noted that the cyanobacteria was measured lower as 10.7 %. Also, in the study sites cell density and occurrence frequency of cyanobacteria were relatively lower than compared to the same measurements noted in other rivers.