• 한국수산과학회지
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• 제27권6호
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• pp.690-695
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• 1994

혐기-호기 체계의 활성오니를 이용하여 폐수로부터 인과 질소를 동시에 제거하는 연구를 행하였다. 혐기적인 조건에서 nitrate 혹은 nitrite의 농도가 거의 0일 때, 제거된 glucose의 양은 orthophosphate의 방출과 직선적인 관계를 나타내었으며, 유입수에서 인과 glucose의 비율이 0.04 이하일 때, 폐수 중의 인은 호기적인 단계에서 거의 제거되었다. 이는 혐기적 단계에서 받은 stress로 인해 호기적 단계에서 받은 stress로 인해 호기적 단계에서 훨씬 많은 양의 인을 흡수한 것으로 생각된다. 혐기적 단계에서의 인의 방출양과 호기적 단계에서의 인의 흡수양은 $NO_x-N$의 농도와는 비례적인 관계가 아니었으며, 더우기, glucose에 대한 $NO_2-N$의 비가 0.37보다 낮을 때, 유입수 중의 무기질소는 완전히 제거되었다.

• 한국환경과학회지
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• 제16권11호
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• pp.1271-1277
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• 2007

This study was conducted to investigate the ratios of phosphorus release to COD uptake, phosphorus release to nitrate removal, and phosphorus uptake to phosphorus release by DNPAOs(denitrifying phosphate accumulating organisms). In case $I{\sim}IV$, influent 1 were fed with synthetic wastewater with influent 2 $NO_3^--N$ injection to anoxic zone and the case V were fed with municipal wastewater with side stream oxic zone instead of influent 2 $NO_3^--N$ injection. As a result, the ratio of phosphorus release to carbon uptake was increased in accordance with nitrate supply. The DNPAOs simultaneously took up phosphate and removed nitrate from the anoxic reactor. In case $I{\sim}IV$, with above 20 mg/L of sufficient $NO_3^--N$ supply, phosphate was taken up excessively by the DNPAOs in anoxic condition. The large amount of both uptake and release of phosphorus occurred above 20 mg/L of nitrate supply, achieving the ratio of phosphorus uptake to phosphorus release to be 1.05. In case V, phosphate luxury uptake was not occurred in system due to 6.98 mg/L of insufficient $NO_3^--N$ supply and the ratio of phosphorus uptake to phosphorus release was 0.98. Consequently, if nitrate as the electron acceptor was sufficient in anoxic zone, the ratio was found to be high.

• 한국물환경학회지
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• 제20권2호
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• pp.104-109
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• 2004

Removal of nutrients from domestic sewage or industrial wastewater is needed to protect surface waters from eutrophication. This research was carried out to remove the nitrogen (N) and phosphorus (P) from the wastewater using the iron oxide obtained from the steel industry and the natural zeolite, respectively. This research was conducted in both batch and continuous systems. The removal efficiency of the nutrients was evaluated in the batch system using the varying concentrations of zeolite and iron oxide added. The removal efficiency of N was 60% at the 8g of zeolite added. In the same condition, the removal efficiencies of N were 76% and 82% at 12g and 16g of zeolite added, respectively. Removal efficiency of P was 80% as 8g of iron oxide was added. The removal efficiency of P was correspondingly increased as the concentration of iron oxide was increased. Continuous column system was also used to evaluate the removal efficiency of N and P by the addition of zeolite and ferric oxide, respectively. Removal efficiencies of N were compared in the mixed packing, two stage, and four stage columns, respectively. The removal efficiencies (80%) of N in the separate packed columns (two and four stages) were higher than the mixed packing column (400%) after 90 hr. Whereas, the removal efficiencies of P were similar to each other in the three columns.

• 한국축산시설환경학회지
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• 제6권2호
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• pp.83-89
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• 2000

In general, livestock wastewater consists of many pollutants such as nitrogen, phosphorus, carbonic compounds and inorganic substances. Most carbonic and organic compounds are sufficiently removed by conventional secondary processes, but nitrogen, phosphorus and soluble inorganic compounds are little removed by traditional clarification process. These remained substances in wastewater, for instances, phosphorus and nitrogen are efficiently eliminated by advanced wastewater treatment or botanical removing process. Concentrations of $BOD_s$, SS, T-N and T-P in influent livestock wastewater used in this study were 126mg/l, 115mg/l, 45mg/l and 13mg/l, respectively. The hydraulic retention time(HRT) of wastewater was about 10 days in the pond packed with aquatic plants. A water-hyacinth and a water-dropwort were used as an experimental stuff plant. The removal ratios of nitrogen was 44.3% for the water-hyacinth and 40.2% for the water-dropwort. The removal efficiency of phosphorus in experimental ponds reached by 57.9% for the water-hyacinth and 58.5% for the water-dropwort for 10 days, respectively. Removal ratios of BODs and SS of livestock wastewater for 10 days were reached by 80.1%, 91.0% for he water-hyacinth, respectively. At the same condition, the removal ratios of BODs and SS were reached by 75.0%, 87.6% for the water-dropwort, respectively.

• 환경위생공학
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• 제7권1호
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• pp.45-56
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• 1992

The Anaerbic Anoxic/oxic process is one of the biological treatment methods to remove nitrogen and phosphorus effectively which are nutritional elements for eutrophication. Supernatant of primary sediment of Anaerobic digester is used as a carbon source instead of methanol methanol supply in usual A$_{2}$/O process. The efficiency of the following treatment processes are as follow : 1) Changing recycle ratio in the usual A$_{2}$/O process without the stage of Anaerobic digester. 2) Changing recycle ratio in the usual A$_{2}$/O process with the supernatant supply of the Anaerobic digester. In the result of comparison, changing recycle ratio is almost no effect in the removal of phosphorus, however the effect of removal in nitrogenous substance are remarkable, and the effect of Anaerobic digester is not as effective as expected because the BOD removed in the digester partly, the rate of phosphorus to the BOD exceed pertinent range.

• 한국물환경학회지
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• 제28권1호
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• pp.71-77
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• 2012

The performance and characteristics of nutrient removal in wetlands influenced by plant type. We tested a floating plant, Eichhornia crassipes, and a submerged plant, Ceratophyllum demersum, under the same environmental conditions to understand the differences in nutrient uptake by these different plant forms. The total nitrogen and phosphorus in the water decreased in the following order: Water Only < Water + Soil < Floating Plants ${\approx}$ Submerged Plants and Water Only < Water+Soil < Floating Plants < Submerged Plants. Nitrogen and phosphorous concentrations increased in both plants; however, the phosphorous concentration was greater in C. demersum than E. crassipes. The submerged plant exhibited higher phosphorus uptake per unit biomass than the floating plant, but nitrogen uptake did not differ significantly. These results suggest that the presence of soil influences nitrogen and phosphorus removal from water, and that wetland plants play an important role in the assimilation and precipitation of phosphorus. Understanding the differences in contaminant removal performance and characteristics of various plant forms can help in the selection of diverse plants for constructed wetlands to improve water quality and provide ecosystem services such as wildlife habitat and landscape enhancement.

• Fisheries and Aquatic Sciences
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• 제13권2호
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• pp.133-139
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• 2010

The effects of suspended solids size on culture water quality were determined in a commercial recirculating aquaculture system (RAS) for Japanese eel, Anguilla japonica. The particulate phase of the culture water was serially divided into six size fractions using 300, 200, 100, 75, 45, and 26 ${\mu}m$ pore size stainless sieves. The total, dissolved, and particulate nitrogen and phosphorus, and suspended solids for each fraction were determined. The concentration ranges in the fractions were: total nitrogen, 164-148 mg $L^{-1}$; total phosphorus, 20.4-15.5 mg $L^{-1}$; and total suspended solids, 8.1-6.1 mg $L^{-1}$. The concentration of total nitrogen and total phosphorus decreased significantly (P<0.05) with a 26 ${\mu}m$ and 200 ${\mu}m$ filter pore size, respectively. Nutrients from dissolved organic substances were much higher than from particulates. Analysis of particle size fractionation and its effects on water quality is useful to estimate removal efficiencies of a commercial effluent screening device for solid management and development of solid removal systems.

• 상하수도학회지
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• 제24권1호
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• pp.73-83
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• 2010

This study was performed to increase the removal efficiency of the biofilter packed with granular sulfur in municipal wastewater reclamation facility. Constituent units were influent water tank, denitrification tank, BOD reduction tank and outlet. And, the major operation factor is a biofilter packed with submerged granular sulfur. Actual wastewater and synthetic wastewater were used as influent wastewater. Experimental condition was divided into two phases according to the amount of a phosphorus coagulant. Total phosphorus removal efficiency was insignificant at mode I that phosphorus coagulant was not injected. The average influent and effluent total phosphorus concentrations at mode II were 0.5 ~ 1.0 mg/L and 0.27 mg/L, respectively. As for COD and BOD effluent concentrations, COD was 3.0 mg/L and BOD was 1.0 mg/L. Additionally, nitrogen removal rates were high at low influent DO concentration. In conclusion, a new process, biofilter packed with granular sulfur is expected to treat high-rate nitrogen wastewater and expected to be utilized as an alternative of technological innovation for the nitrogen treatment.

• 한국환경과학회지
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• 제6권4호
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• pp.409-415
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• 1997

In order to Investigate the possibility as a simple technique of wastewater treatment for recirculating aquaculture system, the experiment by a biofilter unfit was carried out. The high and stable removal efficiency of nitrogen could be obtained by selecting the optimum recycle ratio and DO concentration. It was found that the proper combination of nitrifacation and denitrfication step in the reactor would be required for increasing the removal efficiency. The extent of nitrogen removal gradually decreased UO the rise of re- cycle ratio since the depression of denitrificatlon by the lack of hydrogen donor. The depression of nitrogen removal was overcome by increasing the CIN ratio In the wastewater. The extent of phosphorus removal was increased slightly with the increase of DO concentration and recycle ratio, but high removal efficiency was not observed. However, the extent of COD removal was not affected by recycle ratio and DO concentration and showed the stable removal of above 90%.

• Journal of Life Science
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• 제9권2호
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• pp.40-43
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• 1999

In the wastewater treatment experiment by anaerobic-aerobic packed bed unit, it was found that the high and stable removal efficiency of nitrogen could be obtained. The extent of nitrogen removal gradually decreased with the rise of recycle ratio and DO concentration. On the other hand, the extent of phosphorus increased with the increase of DO concentration. COD showed high removal efficiency over the entire range tested. The simulation of T-N behavior was carried out satisfactorily by using the kinetic equations for biofilm and the reactor model which considered the packed bed as a plug flow reactor.