• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.2
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• pp.86-96
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• 2010

The oxygen utilization rate (OUR) is one of the crucial parameters for ocean carbon cycling and climate models. However, parameterization of OUR in the East Sea (Sea of Japan) is yet to be established. We estimated the basin-specific OURs in the East Sea and fitted them with exponential functions with depth by using pCFC- 12 age and apparent oxygen utilization (AOU) measured in summer 1999. The estimated OURs are higher in the upper water column and decrease with depth, in general. The vertical distributions of the estimated OURs in the Western and Eastern Japan Basins (WJB & EJB) are very similar. The OURs in the Ulleung Basin (UB) varied greatly depending on whether the surface layer (0~200 m) data are included in the OUR estimate or not. Apparently, weaker oxygen consumption occurs in the deep layer of Yamato Basin (YB). The ranges of the OURs between 200 m and 2000 m at WJB, EJB, UB, and YB are 8.15~0.83, 8.11~0.68, 5.29~0.73, and 7.31~0.06 ${\mu}mol$ $kg^{-1}$ $yr^{-1}$, respectively. Consideration of the wintertime surface water oxygen disequilibrium condition in estimating the OUR will be necessary in the future study.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.7
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• pp.479-484
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• 2013

This study was performed to examine the effect of copper on the biodegradability, nitrification, denitrification and oxygen uptake rate (OUR) using batch reactor and continuous flow stirred tank reactor (CSTR) of anaerobic/anoxic/oxic ($A_2/O$). The results of this study can be summarized as follows. In the case of the effect of copper on organic treatment, the bad effect initiated when it was above 4.5 mg/L copper with batch reactor and above 2.0 mg/L copper with CSTR. Concerning the case on nitrification and removal of nitrogen, it showed bad effect when copper was above 4.5 mg/L with batch reactor for nitrification and 1.0 mg/L with CSTR for the removal of nitrogen. The bad effect on the removal of phosphorus began when it was 4.5 mg/L copper with batch reactor and 2 mg/L copper with CSTR. In the case of OUR, it decreased as microbial activity was affected when copper concentration was above 1.5 mg/L in both case of batch reactor and CSTR.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.4
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• pp.228-233
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• 2015

This study was performed to examine the effect of zinc on the biodegradability, nitrification, denitrification and oxygen uptake rate (OUR) using batch reactor and continuous flow stirred tank reactor (CSTR) of anaerobic/anoxic/oxic ($A^2/O$). The results of this study can be summarized as follows. In the case of the effect of zinc on organic treatment, zinc had no effect up to 12 mg/L with batch reactor but biodegradability was lowered when it was above 3.0 mg/L with CSTR. Concerning the case on nitrification and removal of nitrogen, nitrification rate was lowered when zinc was above 6.0 mg/L with batch reactor and removal rate of nitrogen was lowered when zinc was above 3.0 mg/L with CSTR. Removal rate of phosphorus was lowered when it was above 6.0 mg/L zinc with batch reactor and above 3.0 mg/L zinc with CSTR. In the case of OUR, it decreased as microbial activity was affected when zinc concentration was above 3.0 mg/L in CSTR.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.4
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• pp.989-997
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• 1994

The major objective of this study is to develop an effective method to estimate ${\alpha}$ and ${\beta}$ in an aeration basin at a conventional activated sludge wastewater treatment plant. A series of unsteady state batch tests were simultaneously performed with clean water and mixed liquor in two batch reactors under identical operational conditions. Oxygen uptake rates (OURs) of the mixed liquor were measured during the tests. The results show that the OURs due to synthesis respiration and endogenous respiration were averaged about $17.96 mg/(l{\cdot}hr)$ and about $12.29mg/(l{\cdot}hr)$, respectively. The corresponding ${\alpha}$ and ${\beta}$ were ranged between 0.65 to 0.95, and between 0.88 to 0.93, respectively. Based on the overall experimental results, the proposed experimental test method and the proposed method for determination of ${\alpha}$ and ${\beta}$ are found to be relatively simple and easy to use in evaluating the characteristics of aeration systems.

• Journal of Wetlands Research
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• v.17 no.3
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• pp.293-302
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• 2015

This study investigated sediment oxygen consumption rates and geochemical characteristics of sediment in hypoxic area of the Gamak Bay based on the chamber experiments and geochemical analyses. The organic carbon contents of surface sediment in the Gamak Bay showed that the inner bay area has higher organic carbon content than those of the outer bay. They toward the outer bay, contents dropped off. The vertical profiles of calcium carbonate ($CaCO_3$) content at piston core sediment assumed that the hypoxia have been frequently occurred during past century in the northern inner bay. The benthic chamber experiments were conducted in February, May, August and November 2010, 2011 in the hypoxic area of the Gamak Bay. In the sediment incubation experiment with chamber at site C3 in the northern inner bay and site C17 in the southern outer bay, the sediment oxygen consumption rate ranged from $3.98mmol\;m^{-2}d^{-1}$ to $12.43mmol\;m^{-2}d^{-1}$ and $3.28mmol\;m^{-2}d^{-1}$ to $8.18mmol\;m^{-2}d^{-1}$, respectively. When the oxygen was completely depleted, the toxic hydrogen sulfide was released with $1.38mmol\;m^{-2}d^{-1}$ and $1.3mmol\;m^{-2}d^{-1}$, respectively.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.463-466
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• 2000

In this study, it was observed to oxygen uptake rate(OUR) on microbes in activated sludge process. OUR was showed to 43, 55, and $64\;mgO_2/L/hr$ when inoculated microbes mass were 3, 5, and 10%(v/v%). In additon to oxygen was consumed to $4{\sim}42\;mgO_2/L/hr$ as changed substrate concentration. Also, we were measured kinetics coefficient in order to know growth tendency. It was concluded to maximum growth rate$(\;{\mu}\;_{max})$, $2.7\;day^{-1}$, yield coefficient, 0.655, and half-velocity coefficient, 36.11 mg/L.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.1
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• pp.30-39
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• 2004

In order to understand the environmental impact of marine cage fish farms, we measured the vertical fluxes of particulate to the sediment, the distribution of organic carbon in core samples, sediment oxygen consumption rate (SOD), and macrobenthos with increasing distance from a fish cage in Miruk island located in Tongyong. The experiment was performed in August 2003. Measured values gradually decreased with distance, indicating that the organic matter in the sediment derived from the fish farm. The dominant macrobenthos species were Tharyx mulifilis, Lumbrineris longifolia, Sigambra tentaculata, and Capitella capitata, occupying 88% of the total population. Capirella capirata, an opportunistic polychaete species, were especially abundant between 0 to 5 m radius range. The estimated impact regions of organic matter enrichment based on sediment consilmption rates and compositions of macrobenthos were in good agreement. Most organic matter derived from the fish farm was deposited within a 10 m radius and then dispersed horizontally to nearby (at least 50 m) surface sediment. The vertical organic carbon fluxes to the sediment at the fish farm were higher by a factor of two than those outside the area. The remineralization organic carbon in the upper sediment layer was estimated to be 50% (1.07 g C m$^{-2}$ day$^{-1}$ ) at the fish farm. In contrast, outside the area, 30% (0.30 g C m$^{-2}$ day$^{-1}$ ) of organic carbon was recycled and the remaining 70% was deposited to the deep sediment layer.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.4
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• pp.216-224
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• 2006

To clarify the formation process and characteristics of oxygen deficient water mass in Gamak Bay, oxygen deficiency was weekly observed from 17 June to 12 September 2005. Surface water temperature was significantly lower in the outer bay than in the inner bay, whereas the bottom water temperature was higher in the central area of bay than in the outer and inner bay. The vertical stratification of water mass was strongly formed during the period, and thermocline was observed between 3 and 5m deep. The oxygen deficiency in the bottom layer began to appear at early July in the inner bay and gradually spread to the center area of the bay in early August. The mean transparency and light attenuation coefficient($K_d$) in water mass was 4.0m and 0.47, respectively. Average concentrations of nutrient and chlorophyll ${\alpha}$ in the bottom layer were significantly higher than those in surface, and those concentrations were significantly higher in the inner bay than in the outer bay. During the formation of oxygen deficiency in the bottom layer, oxygen penetration depth in the bottom sediment were extremely shallow, and oxygen consumption rate in the bottom sediment were lower than that in the area where oxygen deficient water mass disappeared. Dissolved oxygen concentrations in the bottom layer are negatively correlated with nutrient concentrations, whereas those in the surface layer did not show a significant relationship with nutrient concentrations. Elevated loss of oxygen in the bottom water mass was attributed to the increase of the oxygen consumption rates in sediments and the decomposition of organic matter by microorganism.

• Ocean and Polar Research
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• v.32 no.4
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• pp.439-448
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• 2010

General consensus on typical vertical profile of dissolved oxygen in the Ulleung Basin is that dissolved oxygen concentration beyond 300 m decreases with increasing depth. However, the results of our observations in 2005 and 2006 revealed three different dissolved oxygen distribution types in the deep layer of the Ulleung Basin. The first type showed oxygen concentration decreasing with increasing depth (Type-1), the second showed oxygen concentration decreasing very sharply near the bottom boundary layer but constant in the bottom adiabatic layer (Type-2), the final was of the oxygen minimum layer above the bottom boundary layer (Type-3). Type-2 was the most common pattern in the Ulleung Basin. Type-1 was most common close to the Japan Basin, including the Ulleung Interplane Gap, while Type-3 was found around Dok do. Oxygen Consumption Rate (OCR) at surface sediment estimated using the dissolved oxygen distribution at the bottom boundary layer was $0.2{\sim}5.8\;mmol{\cdot}m^{-2}d^{-1}$, which coincided with OCR from direct sediment incubation. This implies that organic matter decomposition at surface sediment may play an important role in dissolved oxygen distribution patterns at the bottom boundary layer of the Ulleung Basin.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.374-379
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• 2000

To elucidate the degradation mechanisms of organic materials in Lake Paldang, oxygen consuming rates in the water column, high molecular weight (HMW) organic materials and aggregates were analyzed. Also the chlorophyll a concentrations and environmental factors were measured three times in 1999. The concentrations of chlorophyll a ranged $5.5{\sim}14.2\;mg/m^3$ with the highest peak of $57.7\;mg/m^3$ at the surface water in April. Chlorophyll a concentration of aggregates retrieved from traps in 5 m and 20 m depths in May were 2779.5, $9044.8\;mg/m^3$, respectively. Those vlaues were more than 6 times higher compared with other months, and more than 49 times higher than water column chlorophyll a. Oxygen consuming rates of water column were in the narrow range of $0.4{\sim}0.5\;mg\;O_2\;l^{-1}\;day^{-1}$. HMW organic materials were using only small amount of oxygen, $0.01{\sim}0.04\;mg\;O_2\;l^{-1}\;day^{-1}$. The aggregates retrieved from 5 m depth by sediment trap consumed the oxygen in the range of $0.48{\sim}0.69\;mg\;O_2\;l^{-1}\;day^{-1}$, while aggregates collected from 20 m depth, 0.88 to $1.04\;mg\;O_2\;l^{-1}\;day^{-1}$. With these results, the HMW appeared not to be degraded in the water column, instead they seemed to be concentrated and affected the sediment oxygen demand.