• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.7
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• pp.878-884
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• 2017

It is important to understand interactions in the sediment-water environment because nitrate (N) and phosphorus (P) nutrient fluxes released into overlying water can represent a significant fraction of the total nutrient requirement for primary productivity. In this study, we analyzed and estimated benthic nutrient fluxes at the sediment-water interface, investigating environmental conditions in Gomso and Geunso Bays. Also, we compared previously reported nutrient flux data to identify regional differences. As a result, benthic nutrient fluxes in Beopsan were DIN: $6.14mmol\;m^{-2}d^{-1}$ and DIP: $0.32mmol\;m^{-2}d^{-1}$ higher than other survey sites. Sediment COD were $4.0-10.8mg/g{\cdot}dry$, and environmental deterioration was observed due to organic pollution. If no solution is found for tidal flat farm management, problems such as a decrease in aquaculture production will follow. Therefore, long-term monitoring of tidal flat environments should be pursued to enable the sustainable use of biological resources.

• Journal of environmental and Sanitary engineering
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• v.10 no.3
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• pp.56-66
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• 1995

To investigate environmental impacts of inland fish- farms on the water quality of a stream, environmental parameters including physical, chemical and biological factorswere estimated at trount- farm in 1994. Influences( F-1) were polluted as passing through fish tank( F-2) and settle pond( F-3), so organic and inorganic nutrient concentrations became very high in effluents( F-4). BOD$_{5}$, Chl. a, Nitrite and heterotrophic bacterial numbers in the junction site(5-2) of F-4 and S-1( upstream) were highest among the stream sites. BOD$_{5}$ was proved to a good parameter of organic pollution, and nitrite of Inorganic nutrients in the fishery and it's affected stream, The high concentration of BOD$_{5}$ and Chl. a in S-2 were decreased in downstream(5-3, 5-4). It seems that this results are due to dilution or sedimentation effect. This supposition requires further testing about the sediment of stream. The results of this paper demonstrate that fish farming can deteriorate water quality of a stream by changing environmental factors.

• Journal of environmental and Sanitary engineering
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• v.13 no.2
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• pp.57-65
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• 1998

In this research, Effect of C/N ratio on nutrient removal in intermittently aerated activated sludge system(IAASS) was investigated with dormitary, building and swine wastewater. Three types (2-stage, 4-stage, modified) of IAASS were operated. Time interval of aeration/nonaeration in IAASS was 1hr/1hr. In treatment of Dormitary wastewater(BOD/T-N ratio : 4.4), Building wastewater (BOD/T-N ratio : 3.14) and swine wastewater(BOD/T-N ratio : 3.84), Nitrogen removal efficiency of 80, 70 and 90.4% was achieved, respectively. Nitrogen removal in IAASS was a great influenced on influent C/N ratio, efficient nitrogen removal was achieved at BOD/T-N ratio over 4. In IAASS operation, $\Delta $BOD mg/L/$\Delta $ nitrogen mg/L ratio was about 4-6. Simultaneous removal of organic, nitrogen and phosphorus in IAASS can achieved. And influent organic was efficiently utilized in denitrification. IAASS could be one of the best alternative process for the retrofit of conventional activated sludge system for the removal of nutrients.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.275-280
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• 2001

Typically, manganese (II) ions are incompletely removed from water as $MnO_2$ on increasing the pH of the water to 10. The water then has to be neutralized before it can be used. We propose a new and effective method for removing Mn (II) from water using a new combination of symbiotic microbes consisting of manganese-oxidizing bacteria and filamentous algae. The microbes rapidly oxidize Mn(II) to Mn (IV) at a neutral pH with no organic matter required as a nutrient and $MnO_2$is precipitated immediately. This differs from the use of heterotrophic manganese-oxidizing bacteria where organic nutrients are required. Our results suggest that this method will be useful in developing new systems for removal of manganese(II) ions from industrial and mining wastewater and drinking water. In addition, there are other possibilities such as recycling of dry batteries which are presently discarded without treatment

• Journal of Environmental Health Sciences
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• v.18 no.2
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• pp.57-61
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• 1992

This study was made for enhanced removal of N and P by intermittented aeration Activated Sludge Process. Experiment were conducted to find the effects of aeration interval and nutrient removal efficiency. When applied aeration interval were 30~60 min, 2~4 h, 4~8 h, organic matter was not affected while phosphorous removal was aeration interval 30~60 min. Also, when applied mixing intensity were 15, 30, 45 and 60 rpm, organic matter was not affected while removal was maximum at 15 rpm. Total nitrogen and phosphorous removal were in the range of 76 and 85%. Density and MLSS of Sludge were in the range of 2.3~2.6 and 7198~7810 mg/l. Release of phosphorous from activated sludge under unaerobic condition was increased as pass time.

• Journal of Environmental Science International
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• v.7 no.5
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• pp.591-598
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• 1998

This study was conducted to evaluate water quality in the Keum River estuary using principal component analysis. The results was summarized as follow; Water quality in the Keum River estuary could be explained up to 70.40% by three factors which were included in the inffluent loading by the Keum River and Kyungpo cheon(38.99%), seasonal variation and organic matter pollution(19.05%), sediment resuspension and internal metabolism(12.35%). For spatial variation of factor score, artificial pollutant loading is highest at st.1, below Keum River barrage, and decreases toward the outer sea. For annual variation of factor score, factor 1 was highly related to artificial pollutant leading, and it was gently increased in 1994. Also, organic matter pollution, sediment resuspension and internal metabolism were increased to every year. It is necessary to control the nutrient leading by Keum river and Kyongpo cheon for Water quality management of estuary.

• ALGAE
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• v.31 no.3
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• pp.189-204
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• 2016

Microalgal bioremediation of CO₂, nutrients, endocrine disruptors, hydrocarbons, pesticides, and cyanide compounds have evaluated comprehensively. Microalgal mitigation of nutrients originated from municipal wastewaters, surface waters, and livestock wastewaters has shown great applicability. Algal utilization on secondary and tertiary treatment processes might provide unique and elegant solution on the removing of substances originated from various sources. Microalgae have displayed 3 growth regimes (autotrophic, heterotrophic, and mixotrophic) through which different organic and inorganic substances are being utilized for growth and production of different metabolites. There are still some technology challenges requiring innovative solutions. Strain selection investigation should be directed towards identification of algal that are extremophiles. Understanding and manipulation of metabolic pathways of algae will possible unfold solution to utilization of algae for mitigation of dissolve organic nitrogen in wastewaters.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42
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• pp.38-49
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• 2000

Two application rates (9 and 18 t/ha) of poultry litter and a recommended rate of commercial fertilizer were studied to determine their effects on nutrient (N and P) losses in surface and subsurface runoff and loadings in soil layers from conventionally-tilled com by the treatments. The model predicted higher sediment losses than observed data from all treatments. The overpredicted sediment losses resulted in overprediction of organic-N and sediment-P losses in surface runoff. Simulated soluble-P losses in surface runoff were close to observed data, while NO3-N losses in surface runoff were underpredicted from all treatments. Observed NO3-N concentrations in leachate at 1.0-m depth from commercial fertilizer treatment were fairly well predicted. But the concentratins were overpredicted from poultry litter treatments due to high simulation of organic-N mineralization simulated by the model.

• Journal of Environmental Health Sciences
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• v.19 no.4
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• pp.33-37
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• 1993

The problem for the removal of phosphorus increased due to reasons like eutrophication control. However its removal and operating criteria were not well developed. This study was made for enhanced removal of P by iron contactor by intermittent aeration activated sludge process. Experiment was conducted to find the effects of organic substance load and HRT, nutrient removal efficiency. When applied organic substance load and HRT, II &III reactor were good treatment efficient while come from Fe of iron contactor. Release of phophorus from II &III reactor sludge under anaerobic condition was low. As the process developed, the content of released ionized Fe from iron contactor increased. In addition, the rate of phosphorus removal became accelerating, and the removed sludge was stabilized in the existence of insoluble status.

• Journal of Plant Biology
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• v.13 no.3
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• pp.20-24
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• 1970

In the moor of Mt. Dae-am, the following communities are seen in successive order ranging from the north to the south; the Sanguisorba Argutipens-Carex jaluensis community, the Carex jaluensis-Sanguisorba Argutipens-Sphagnum community, the Sphagnum cymbifolium-Carex jaluensis community, the Carex jaluensis-Sanguisorba Argutipens community and the Calamgrostis Langsdorfii-Ottelia alismoides community. The properties of the peats vary according to the community type, that is, nutrients such as organic matter, total nitrogen, exchangeable K and Mg in the soil tend to decrease as the plant communities shift from the north to the south. The pH range for eleven stations samples was 3.9 to 5.7, and the meadian is 4.6. The content of exchangeable Ca decreases from station to station successively towards the center which is poor in calcium. Presumably there appears to be a clear correlation of Sphagnum cymbifolium with the amount of exchangeable Ca and value of pH produced in bogs by the breakdown or organic residures. The nutrient content of the representative plants of the moor shows no definite relation with the station of their habitats.