• 한국물환경학회지
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• 제21권6호
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• pp.595-601
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• 2005

In this research, effects of water circulation on phosphorus release from sediment into water body were studied. Sediments sampled at the Daechung Lake were used for the column experiments with circulation and non-circulation conditions. Deaeration coefficient, $K_1$ and reaeration coefficient, $K_2$ of non-circulation condition were 0.133 and 0, respectively, while $K_1$ and $K_2$ for circulation condition were 0.46 and 0.018, respectively. Oxidation Reduction Potential (ORP) showed a linear relationship with dissolved oxygen (DO) when DO is over 2 mg/L. Phosphorus concentration induced by phosphorus release from sediment was highly dependent upon DO, ORP, and pH. Under anaerobic condition, phosphorus release rate was higher for $Fe^{2+}$-bounded phosphorus compared to that of $Ca^{2+}$-bounded phosphorus.

• 한국양식학회지
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• 제14권2호
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• pp.67-71
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• 2001

Phosphorus is an essential element for growth and metabolism in fish. However high levels of phosphorus in the feed can lead to poor water quality of pond, and can also be a potential source of pollution, when pond water is released to the environment. In this study phosphorus supplemented diets containing 0.0, 0.9 or 1.9% of (dicalcium) phosphate were offered to channel catfish and changes in water quality of ponds and phosphorus levels in fish were measured. Higher level of (1.9%) supplementation of phosphorus in diet resulted in higher concentration of T-P and SRP in pond waters. Also it produced negative effects on fish production by lowering feed coefficient and rate of increment in body weight. Surplus phosphorus can affect fish growth and water quality of pond.

• Journal of Applied Biological Chemistry
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• 제44권1호
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• pp.16-19
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• 2001

Soybean plants(Glycine max [L.] merr.) inoculated with Bradyrhizobium japonicum MN110 were grown in growth chambers under 400 or $800{\mu}l{\cdot}l^{-1}$ atmospheric $CO_2$ and harvested at 25, 28, 32, and 35 DAT to examine the effect of $CO_2$ enrichment on phosphorus accumulation, uptake, and utilization efficiency during vegetative growth. Phosphorus concentration in leaf was lower in high $CO_2$ plant by 47% at 25 DAT and 34% at 35 DAT than those in the control plant but phosphorus concentrations in stem, root and nodule were not affected by $CO_2$ enrichment. Total phosphorus accumulation increased 3.9-fold in high $CO_2$ plant and 3.2-fold in the control plant between 25 and 35 DAT. Elevated $CO_2$ caused a decrease in the whole plant phosphorus concentration by 35%, which was due almost entirely to a decrease in the phosphorus concentration of leaves. $CO_2$ enrichment increased phosphorus utilization efficiency in the whole plant by 70% during the experimental period. Plants exposed to high $CO_2$ had larger root systems than under ambient $CO_2$, but high $CO_2$ plants had lower P-uptake efficiency. Averaged over four harvests, plants at high $CO_2$ had 38% larger root mass that was more than offset the 20% lower efficiency of P-uptake and accounted for increased phosphorus accumulation by high $CO_2$ plant. These results suggest that the reduced phosphorus concentration in soybean plant under $CO_2$ enrichment may be an acclimation response to high $CO_2$ concentration or enhanced starch accumulation, resulting in the plants to have a lower phosphorus requirement on a unit dry weight basis or a high phosphorus utilization efficiency under these conditions.

• Membrane and Water Treatment
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• 제11권1호
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• pp.59-68
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• 2020

The study objective was to evaluate the enhanced removal of high concentrations of phosphorus from synthetic wastewater (solely phosphorus-containing) and real wastewater (pig manure) by using carbon nanotube (CNT)-coated steel slag. Generally, phosphorus removal by steel slag is attributed to Ca²⁺ eluted from the slag. However, in this study, CNT was used to control the excess release of Ca²⁺ from steel slag and increase the phosphorus removal. The phosphorus removal rate by the uncoated steel slag was lower than that of the CNT-coated steel slag, even though the Ca²⁺ concentrations were higher in the solution containing the uncoated steel slag. Therefore, the phosphorus removal could be attributed to both precipitation with Ca²⁺ eluted from steel slag in aqueous solution and adsorption onto the surface of the CNT-coated steel slag. Furthermore, the protons released from the CNT surface by exchanging with divalent cations acted to reduce the pH increase of the solution, which is attributed to the OH^- eluted from the steel slag. The adsorption isotherm and kinetics of the CNT-coated steel slags followed the Freundlich isotherm and pseudo-second-order model, respectively. The maximum adsorption capacity of the uncoated and CNT-coated steel slags was 6.127 and 9.268 mg P g^-1 slag, respectively. In addition, phosphorus from pig manure was more effectively removed by the CNT-coated steel slag than by the uncoated slag. Over 24 hours, the PO₄-P removal in pig manure was 12.3% higher by the CNT-coated slag. This CNT-coated steel slag can be used to remove both phosphorus and metals and has potential applications in high phosphorus-containing wastewater like pig manure.

• Fisheries and Aquatic Sciences
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• 제1권2호
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• pp.180-186
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• 1998

A 10-week feeding experiment was conducted to determine the phosphorus requirement of juvenile Korean rockfish (Sebastes schlegeli). Three replicate groups of fish initially averaging 4.2g were fed the semipurified experimental diets containing graded levels of $NaH_2PO_4\;\cdot\;2H_2O$ to provide from $0.1\%$ to $1.32\%$ total phosphorus level in a flow-through seawater system. Korean rockfish muscle and casein were used as the protein sources of the basal diet. Weight gain, feed efficiency and protein retention of fish fed the $0.35\%$ phosphorus were higher than those of fish fed the $0.1\%$ phosphorus, although no significant improvements $(P>0.01)$ were observed above the level. Determined phosphorus requirement using the broken line model was found to be $0.3\%$ for weight gain. Moisture, protein and lipid contents of whole body and muscle were not affected by dietary phosphorus levels $(P>0.01)$. Lipid contents of liver in fish fed the $0.1\%$ phosphorus were lower than those in fish fed the $0.35\%$ and $1.32\%$ phosphorus $(P<0.01)$. Dietary phosphorus increased ash and phosphorus contents of the whole body, while those of bone were not affected $(P>0.01)$. The data obtained in this study indicate that a $0.3\%$ dietaryphosphorus level could be recommended for the optimum growth and efficient nutrient utilization of juvenile Korean rockfish.

• 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.

• 한국가금학회지
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• 제17권4호
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• pp.284-295
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• 1990

Extrusion을 달리한 밀기울과 무기태린의 첨가수준의 주요 영양소의 소화율에 미치는 영향을 살펴보고자 증체양, 사료섭취량, 사료효율, 영양소별 소화율, 그리고 tibia의 성분량 변화에 대하여 조사하였다. 1) 증체양은 무기태린의 첨가수준이 0.225％, 0.45％일 경우 Extrusion처리구보다 Non－Extrusion처리구에서 높은 경향을 보였으나, 처리간에 유의성은 찾아 볼 수 없었다. 한편 Extrusion처리에 관계없이 무기태린의 첨가로 증체량이 개선되었으며 인을 첨가한 두처리구(0.225％와 0.45％) 사이에서는 유의성을 인정할 수 없었다. 2) 사요섭취양은 무기태린의 첨가구와 무기태린에서 Non－Extrusion처리구보다 Extrusion처리구에서 높은 경향을 찾아볼 수 있었다. 3) 사료효율은 무기태린을 첨가함으로써 개선되었으나, 인을 첨가한 두 처리구(0.225％와 0.45％) 사이에서는 유의성을 인정할 수 없었다. 4) 건물 소화율은 무기태린의 첨가수준이 높을수록 개선되었으나, Extrusion핵과는 인정할 수 없었다. 5) 인을 첨가한 두 처리구(0.225％와 0.45％) 사이에서 단백질 소화율은 Non－Extrusion 보다 Extrusion처리구가 높았으나, 증체에 직접적인 영향은 없었다. 6) Tibia의 Ca과 P의 함양은 무기태린의 첨가수준에 따라 증가하는 경향을 보였으나, 이러한 증가양상에서 P의 첨가수준과의 직접적인 관계는 찾아볼 수는 없었다.

• 생태와환경
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• 제41권4호
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• pp.554-562
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• 2008

To evaluate the limitation for epiphytic and planktonic algal growth, acid extractable inorganic phosphorus (AP), implying the luxury uptake phosphorus, was measured in five reed zones of Lake Biwa. The AP in epiphytic substances was 0.7 to 1.4 mg P surface stem $m^{-2}$ in summer and 1.2 to 2.8 mg P $m^{-2}$ in winter. On the other hand, the amount in planktonic substances was 1.4 to 5.7 mg P m -3 and 0.8 to 5.4 mg P $m^{-3}$ in both seasons. Contribution of AP in the epiphytic and planktonic phosphorus was 23 to 31% and 8 to 27% in summer, and 17 to 22% and 9 to 17% in winter. It suggests that in summer both epiphytic and planktonic algae had been luxuriously taken up phosphate into cells. The weight ratios of C : N : P were averaged 79 : 20 : 1 for the epiphytic substances and 81 : 12 : 1 for the particulate substances. On the other hand, the ratios without the luxurious phosphorus were 93 : 24 : 1 and 103 : 15 : 1, showing much higher values than the Redfield ratio. High ratio in the epiphytic substances indicates that the phosphorus is the limiting parameter, rather than nitrogen, regulating the growth of epiphytic algal populations.

• 한국환경보건학회지
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• 제26권3호
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• pp.43-49
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• 2000

A laboratory experiments were performed to investigate the effects of several factors on the phosphorus removal by waste oyster shells. The waste oyster shells used in this experiments were crushed particle, calcined particle and extracted solution. A higher efficiencies of phosphorus removal were observed, when a particle size of crushed and calcined particle were smaller. The effluent concentration of phosphorus was around 1.6mg/ι in continuous column experiment which packed with crushed particle of waste oyster shell at the influent concentration of PO4-P of 10 mg/ι. But the clogging of column occurred with increasing of throughput volume of influent. The efficiency of phosphorus removal increased with increasing of dosage amount of crushed, calcined particle and extracted solution. When the calcined particle which contained only about 1/10~1/100 of crushed particle was used, the efficiency of phosphorus removal was correspondingly equivalent to the removal efficiency obtained from crushed particle. The efficiency of phosphorus removal by calcined particle after 9 runs repeated use was decreased about 21.5% as that of the first run. The removal efficiency of 100% could have been achieved at the HRT of 18 hours during the continuous treatment of phosphorus by the solution extracted from calcined particle.

• 한국해양환경ㆍ에너지학회지
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• 제4권3호
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• pp.16-27
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• 2001

시화호 퇴적물에서 인의 지화학적 특성을 연구하였다 퇴적인의 가장 큰 형태는 detrital apatite P와 Al-bound P이며 무산소환경이기 때문에 Fe-bound f는 그 비중이 낮았다. 퇴적총인과 유기물의 상관성으로 볼 때, 퇴적물로 제거되는 인의 거동은 유기물에 의해 조절되는 것으로 나타났다. 또한, 유기물 유입의 영향을 직접적으로 받는 정점 Cl에서 정점 C2에 비해 퇴적인의 함량, 유기물과의 상관성, 황산염환원에 의한 공극수내 인산염의 함량 및 플럭스가 높게 나타났다. 결국 시화호 퇴적물에서 인의 함량, 형태 및 공간에 따른 차이는 유기물에 의해 조절되는 것으로 밝혀졌다.