• Proceedings of the KAIS Fall Conference
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• 2007.05a
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• pp.299-302
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• 2007

본 연구는 하 ${\cdot}$ 폐수 중의 유기물뿐만 아니라 질소, 인을 생물학적으로 제거하는 실험을 수행하였다. 공정 내 미생물의 유실을 방지하고 미생물이 고농도 상태로 유지 가능한 부착성장의 한 공법인 RBC에 끈상 나선형 미생물 접촉재를 설치한 반웅기를 이용하였다. 원수는 Glucose 1,800 mg/L, $NH_{4}Cl$ 500 mg/L, $KH_{2}PO_{4}$ 5mg/L를 혼합한 인공폐수를 제조하여 공정에 주입하였고, 그 결과 각각 미생물이 폐수에 적응하는 단계인 Period 1에서는 각 수질 분석 항목의 농도가 점차적으로 감소하는 경향을 보였으며, 정상상태라고 판단한 Period 2에서는 최종적으로 유입수에 대한 유출수의 제거율은 각각 $TCOD_{Cr}$ 94%, BOD 87%, T-N 85%, T-P 89%의 결과를 나타내었다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.1
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• pp.81-88
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• 1983

This experiment was conducted to study about influenced inorganic element contents of flag leaf and chaff with different nitrogen and silicate application in Jinan (sea level 303m). The recommended rate of fertilizer application above N 15kg/10a was poor for dry production increment in cold in July elevation and was demanded increment of silicate. In the elevation of cold in July high rates of nitrogen application produced more incomplete grain and a reduced cold tolerance. These effects were due to over-content of soluble nitrogen within flag leaf and disturbance of uptaking potassium and silicate. On the other hand, the application of silicate could increase yield by promoting resistance to cold- damage. The application of increasing level of nitrogen resulted in increasing the contents of total nitrogen and phosphate in both sterile and fertile glumes. The contents of potassium and calcium were the highest at the level of nitrogen 10 - 15kg/10a, but magnessium was rather high at low nitrogen levels. It is interesting that at any level of nitrogen, over 6% higher silicate contents were noted in the fertile chaff than in the sterile chaff. Application of increasing level of silicate fertilizer decreased total nitrogen contents, but increased the contents of phosphate, potassium. and silicate in the chaff. Increasing rate of silicate content by increasing silicate addition was remarkably higher in the fertile chaff than in the sterile chaff.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.690-695
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• 1994

Simultaneous removal of phosphorus and nitrogen from wastewater was studied by the anaerobic-aerobic system of activated sludge. In the anaerobic stage, most of the influent glucose was removed and orthophosphate was released, when the nitrate and/or nitrite concentration in the wastewater was almost zero. The amount of the released phosphorus was found to be directly proportional to the amount of the removed glucose. When the ratio of phosphorus to glucose in the influent was less than 0.04, the phosphorus in the wastewater was almost completely removed during the aerobic state. Under the anaerobic condition, activated sludge released phosphate and excess removal of phosphate occurred during the aerobic condition. Namely, the stress received in anaerobic period stimulated the uptake of phosphorus in aerobic period. The amounts of phosphorus release in the anaerobic and uptake in the aerobic stage were less in proportional to the concentration of $NO_x-N$. Further, if the initial ratio of $NO_2-N$/glucose was less than 0.37, the inorganic nitrogen in the influent could be completely removed.

• Korean Journal of Ecology and Environment
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• v.36 no.2 s.103
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• pp.161-171
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• 2003

The present study evaluated water quality variation, limiting nutrient, and sediment of a shallow eutrophic lake (Lake Ilgam) in the metropolitan area from 2000 to 2002. According to annual mean chl.a ($77.2{\pm}36.6\;{\mu}g/l) and TP ($66.6{\pm}20.5\;{\mu}g/l) concentration and trophic state index (>60), Lake llgam was in very eutrophic status. Both inorganic nitrogen ($NH_3-N$ and $NH_3-N$) and phosphorus (SRP) concentrations in the water column increased during winter and spring, but decreased during summer followed by the phytoplankton development. Evidence for phosphorus and nitrogen as being the potential limiting nutrients for phytoplankton growth was supported by the ratio of DIN/DIP (by mass) (${\sim}$835.8), TSI derivations analysis, and algal growth potential bioassay. Based on the results of TSI derivations, strong nutrient limitation by both N and P occurred from September to November when P content in sediment (114.6 mg P/kg) was relatively low compared with the summer. Sediment contained a large amount of nitrogen (TKN: 4,452${\pm}$283.0mg N/kg dry sediment). Phosphorus content in sediment (TP: 313${\pm}$155 mg P/kg) was relatively low with temporal change. P release rate (0.29${\pm}$0.02 mg $m^{-2}$ $day^{-1}$) was high under the aerobic condition at pH 9. These results indicate that the sediment could play an important role as a source of a limiting nutrient, and temporal change of P content in the sediment is closely related with water quality, especially algal biomass change in Lake llgam.

• KSBB Journal
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• v.14 no.5
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• pp.606-610
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• 1999

The purpose of this study was to develop and evaluate rotating biological activated carbon(RBAC) process for nitrogen and phosphorus removal with increasing loading rate. The removal efficiency of $NH_4^+$-N was observed to be higher than 96.5% at all runs, and the relative stable levels of effluent $NH_4^+$-N, $NO_2^-$-N, $NO_3^-$-N could be maintained. The removal efficiency of T-N was observed to be higher than 90%, except RUN 1. The T-P removal efficiency was kept between 32.7% and 49.8%, and the amount of biomass was kept between 269 mg/g support and 473 mg/g support with varying loading rate.

• Korean Journal of Microbiology
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• v.46 no.1
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• pp.27-32
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• 2010

We used phototrophic bacteria to remove low concentrated organic materials (CODCr), nitrogen and phosphorus. We applied $COD_{Cr}$ 37.3 mg/L, $NH_3-N$ 4.0 mg/L, and $PO_4^{3-}-P$ 1.0 mg/L (C:N:P=100:10:1) in the batch test, and the removal efficiencies were shown as follow: $COD_{Cr}$ 87.4%, $NH_3-N$ 46.3%, $PO_4^{3-}-P$ 79.7%. The aerobic process with mixed phototrophic bacteria, ceramic media, and media KSP01 showed the removal efficiencies of $COD_{Cr}$, $NH_3-N$, and $PO_4^{3-}-P$, each as 72.7% and 79.2%, respectively in the lab-scale reactor. The maximum $PO_4^{3-}-P$ removal efficiency reached 92.6% by adjusting pH. There were three conditions used to remove $NH_3-N$. The highest removal efficiency was 98.5% with 10.2 L/min of aeration in 1-2 reactors, and the result of applying river-water showed the high removal efficiency of $NH_3-N$ (82.8%). Therefore, this purification system may be useful to control nitrogen and phosphorus at low concentration in field.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.1
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• pp.49-53
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• 1974

Varietal difference in nitrogen metabolism was investigated under water culture system with high (50 or 80ppm) and low (10 or 40 ppm) levels of nitrogen and with two-week minus nitrogen treatment at maximum tillering and heading stage using a leading local variety, Jinheung and high-yielding IR667 line (newly bred tropical variety). 1. In high nitrogen level Jinheung showed higher yield than IR667. vise versa in low nitrogen level. 2. Poor yield of IR667 at high nitrogen may be due to ammonium toxicity that was eliminated by minus nitrogen from culture solution. 3. IR667 was more sensitive to the change of nitrogen environment. 4. With high nitrogen medium Jinheung showed nigher nitrogen uptake and higher capacity of protein synthesis than IR667, and vise versa at low nitrogen medium. 5. From the above facts it could be concluded that Jinheung has higher metabolic adaptability for heavy nitrogen while IR667 has higher structural adaptability for heavy mitrogen and that better productive adaptability will be resulted in the combination of both characteristics.

• Korean Journal of Microbiology
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• v.37 no.4
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• pp.317-324
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• 2001

We have previously developed three stage methane fermentation system capable of digesting food wastes effectively and then releasing high organic wastewater as a final product. In this study, we tried to devise an ecological water treatment system, which can efficiently remove the nitrogen and phosphorus contained in the organic wastewater. The system was made of microbiological filters, algae, and waterfleas. Of two species of alga tested, Selenastrum capricornutum showed higher growth rate and more efficiently removed the nitrogen from the wastewater than by Chlorella sp. In addition, the highest growth rate and the nitrogen removal efficiency could be obtained when high concentrations of $Mg^{2+}\; and\; Ca^{2+}$ were added to the diluted wastewater and the molar ratio of nitrogen to phosphorus was adjusted to 10 : 1. In this study the population relationship between alga and water flea was also examined in a test tube. The initial number of algal cells decreased as the waterflea population increased. However, the number of algal cells gradually increased again when waterflea population decreased partly due to the environmental resistance. From these results, it was believed that the ecological water treatment system could be used for removing the nitrogen and phosphorus from organic wastewater very effectively. Moreover, the waterflea cultured by this system as a final predator could be used as a good foodstuff for fishes.

• Journal of environmental and Sanitary engineering
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• v.12 no.3
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• pp.1-7
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• 1997

이 연구에서는 SBR 공법을 이용하여 질소, 인 동시제거기장에 대해 관찰하고 BOD-SS loading변화에 따른 오염물질 제거효율에 대해 검토하였다. BOD, TN 및 TP 제거율은 $20^{\circ}C$에서 95%, 74% and 81%로 나타났으며, Phosphorus luxury uptake는 호기성이 시작된후 1,2시간후에 각각 67% 및 84%를 흡수 하는 것으로 관찰 되었으며, 호기성 말기의 농도는 $0.9mg/{\ell}$ 이하를 유지하였다. 80% 및 85% 이상의 안정된 질소 제거효율을 유지하기 위해서는 BOD-SS loading 값을 0.15 및 0.08 kg-BOD/kg-SS.day 이하로 유지하여야 하는 것으로 나타났다. 또한 1회 방류수량의 변화에 따른 관찰에서, 반응조 유효용량의 30%, 40% 및 50%를 유출할 경우 TN은 각각 78%, 72% 및 58%를 TP는 각각 81%, 77% 및 66%의 제거효율을 보였다.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.11
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• pp.783-789
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• 2011

Recently, auto-thermal thermophilic aerobic digestion (ATAD) has a great attention for destruction of wasted sludge biomass in wastewater treatment plant. Reduction of sludge concentration has been successfully achieved with pilot scale ATAD and ceramic filtration process in field condition. However, high concentration of COD, total nitrogen (TN) and total phosphorus (TP) was observed in filtrate, which should be treated before recirculation of filtrate to biological wastewater treatment plant. This study was focused on removal of nitrogen and phosphorus contained in the filtrate of ATAD, using struvite crystallization method. The effect of operational and environmental parameters (such as, N, P and Mg ion concentration and molar ratio, pH, reaction time, agitation strength, seed dosage, and reaction temperature) on the treatment of TN and TP with struvite crystallization were evaluated. Magnesium (as $MgCl_26H_2O$) and phosphorus (as $K_2HPO_4$) ions were, if necessary, added to increase nitrogen removal efficiency by the crystal formation. Average concentration of $NH_4^+-N$ and $PO_4^{3-}-P$ of the filtrate were 1716.5 mg/L and 325.5 mg/L, respectively. Relationship between removal efficiencies of nitrogen and phosphorus and molar ratios of $Mg^{2+}$ and $PO_4^{3-}-P$ to $NH_4^+-N$ was examined. Crystal formation and nitrogen removal efficiencies were significantly increased as increasing molar ratios of magnesium and phosphorus to nitrogen. As molar ratio of $Mg^{2+}:PO_4^{3-}-P:NH_4^+-N$ were maintained to 2 : 1 : 1 and 2 : 2 : 1, removal efficiencies of nitrogen and phosphorus were 71.6% and 99.9%, and 93.8% and 98.6%, respectively. However, the effect of reaction time, mixing intensity, seed dose and temperature on the struvite crystallization reaction was not significant, comparing to those of molar ratios. Settled sludge volume after struvite crystallization was observed to be reduced with increase of seed dose and to be increased at high temperature.