• 한국물환경학회지
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• 제20권6호
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• pp.571-576
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• 2004

Since anaerobic/anoxic/oxic process, which is a typical mainstream biological nitrogen and phosphorus removal process, utilizes influent organic matter as an external carbon source for phosphorus release in anaerobic or anoxic stage, influent COD/T-P ratio gives a strong influence on performance of phosphorus removal process. In this study, a bench scale experiment was carried out for SBR process to investigate nitrogen and phosphorus removal at various influent COD/T-P ratio and nitrate loadings of 23~73 and 1.6~14.3g $NO_3{^-}-N/kg$ MLSS, respectively. The phosphorus release and excess uptake in anoxic condition were very active at influent COD/T-P ratios of 44 and 73. However, its release and uptake was not obviously observed at COD/T-P ratio of 23. Consequently, phosphorus removal efficiency was decreased. In addition, the phosphorus release and uptake rate in anoxic condition increased as the nitrate loading decreased. Specific denitrification rate had significantly high correlation with organic materials and nitrate loadings of the anoxic phase too. The rate of phosphorus release and uptake in the anoxic condition were $0.08{\sim}0.94kg\;S-P/kg\;MLSS{\cdot}d$ and $0.012{\sim}0.1kg\;S-P/kg\;MLSS{\cdot}d$, respectively.

• 상하수도학회지
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• 제34권6호
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• pp.437-443
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• 2020

Biological phosphorus removal is accomplished by exposing PAO(phosphorus accumulating organisms) to anaerobic-aerobic conversion conditions. In the anaerobic condition, PAO synthesize PHB(polyhydroxybutyrate) and simultaneously hydrolysis of poly-p resulting phosphorus(Pi) release. In aerobic condition, PAO uptake phosphorus(Pi) more than they have released. In this study, cyanobacteria Synechococcus sp., which is known to be able to synthesize PHB like PAO, was exposed to anaerobic-aerobic conversion. If Synechococcus sp. can remove excess phosphorus by the same mechanism as PAO, synergistic effects can occur through photosynthesis. Moreover, Synechococcus sp. is known to be capable of synthesizing PHB using inorganic carbon as well as organic carbon, so even if the available capacity of organic carbon decreases, it was expected to show stable phosphorus removal efficiency. In 6 hours of anaerobic condition, phosphorus release occurred in both inorganic and organic carbon conditions but SPRR(specific phosphorus release rate) of both conditions was 10 mg-P/g-MLSS/day, which was significantly lower than that of PAO. When converting to aerobic conditions, SPUR(specific phosphorus uptake rate) was about 9 mg-P/g-MLSS/day in both conditions, showing a higher uptake rate than the control condition showing SPUR of 6.4 mg-P/g-MLSS/day. But there was no difference in terms of the total amount of removal. According to this study, at least, it seems to be inappropriate to apply Synechococcus sp. to luxury uptake process for phosphorus removal.

• 대한환경공학회지
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• 제39권9호
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• pp.519-526
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• 2017

본 연구는 영산강 죽산보 상류 퇴적물을 대상으로 퇴적물에 존재하는 무기인의 존재형태를 파악하고 수체에 미치는 잠재적인 가능성을 예측해보고자 실험실 실험을 진행하였다. 이를 위해 현장 퇴적물을 채취하여 7일 동안 배양실험을 진행하였고, 배양 후 퇴적물의 존재형태별 인 및 수층의 총인을 측정하였다. 무기인의 총량은 YS1 지점보다 YS2 지점에서 더 많았으며, 존재형태별 인 중 Al-P와 Fe-P의 비율이 높았다. 두 지점 퇴적물 모두 배양 초기에 비해 배양 7일 후 Al-P, Fe-P 그리고 Ca-P는 증가하였으며, Red-P는 시간에 따라 감소하는 경향을 보였다. 수층의 총인 농도는 YS1 지점에서 배양시간에 따라 증가하는 경향을 보였고, YS2 지점에서는 배양 7일 후 초기에 비해 총인의 농도가 감소하였다. 퇴적물 입자가 조밀한 YS1 지점이 YS2 지점에 비해 수층 총인 농도가 높은 결과로부터 수층의 총인 농도 변화는 퇴적물의 입도에 영향을 받음을 알 수 있었다. 존재형태별 인 중 Fe-P는 수층의 총인 농도와 음의 상관관계를, Red-P는 양의 상관관계를 보였다. 본 연구의 결과로부터, 수층의 총인 농도를 관리하기 위해서는 퇴적물 인의 존재형태별 특성을 지속적으로 모니터링 하는 것의 필요성을 확인할 수 있다.

• 산업기술연구
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• 제16권
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• pp.5-11
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• 1996

While the enhanced biological phosphorus removal(EBPR), in anaerobic/aerobic condition, was known to remove phosphorus by means of metabolism of poly-P microorganisms, the phosphorus removed could be released in the form of ortho-P in the aerobic fixed biofilm reactor. This study was initiated to investigate the cause of ortho-P release in the aerobic fixed biofilm reactor. The resutls indicated that the phosphorus release was caused by autooxidation. The synthesis and release of phosphrous were related to the ORP and the boundary value for the phase change was about 170mV. In the synthesis phase, the phosphorus removal rate per COD removed was $0.023mgP_{syn}/mgCOD_{rem}$. The phosprous contents of the microorganism were 4.3 ~ 6.0% on a dry weight basis.

• 한국가금학회지
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• 제35권2호
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• pp.115-121
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• 2008

본 시험은 microbial phytase을 첨가하여 산란계에 급여시 산란율, 계란 품질, 인 이용율 및 영양소 소화율에 미치는 영향을 조사하기 위하여 수행하였다. 32주령 Hy-Line Brown 갈색계 120수를 공시하여, 4주간 사양시험을 실시하였다. 시험 설계는 CON(control), LP(low phosphorus diet), NP(low phosphorus diet + 0.03% normal microbial phytase) 및 CP(low phosphorus diet + 0.03% coated microbial phytase)로 4개 처리를 하여 처리당 5반복, 반복당 6수씩 완전 임의 배치하였다. 전체 기간 동안 산란율은 CON과 CP 처리구가 LP 처리구보다 높게 나타났다(P<0.05). 난각 강도와 난각 두께는 LP 처리구에 비해 CON, CP 및 NP 처리구가 높게 나타났다(P<0.05). 난황색과 haugh unit에서는 CON, CP 및 NP 처리구가 LP 처리구보다 높게 나타났다(P<0.05). 혈액내 칼슘과 인 농도는 CP 처리구가 LP 처리구에 비해 높게 나타났다(P<0.05). 건물 소화율과 질소 소화율에서는 CP 처리구가 CON, LP 및 NP 처리구에 비하여 유의적으로 증가하였다(P<0.05). 회분소화율은 CON, CP 및 NP 처리구가 LP 처리구에 비해 증가하였다(P<0.05). 칼슘 소화율과 인 소화율에서는 CP와 NP 처리구가 CON과 LP 처리구에 비해 높게 나타났다(P<0.05). 칼슘 흡수량은 CON, CP 및 NP 처리구가 LP 처리구보다 유의적으로 높게 나타났다(P<0.05). 인 흡수량은 CP와 NP 처리구가 CON과 LP 처리구와 비교하여 유의적으로 높게 나타내었다(P<0.05). 질소와 칼슘 배출량은 CON, NP 및 CP 처리구가 LP 처리구에 비해 유의적으로 낮게 나타냈다(P<0.05). 인 배출량은 LP, NP 및 CP 처리구가 CON 처리구에 비해 유의적으로 낮게 나타내었다(P<0.05). 결론적으로, 산란계에 있어 코팅된 microbial phytase의 첨가는 산란율, 계란 품질, 혈액 내 칼슘과 무기태 인, 영양소 소화율과 칼슘 및 인 흡수량을 증진시키며, 질소와 칼슘 배출량을 감소시키는 것으로 나타났다.

• Environmental Engineering Research
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• 제10권5호
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• pp.257-263
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• 2005

A batch and a continuous type experiments were conducted to test the conditions for simultaneous phosphorus release and uptake, and denitrification, taking place in one process. The bacteria able to denitrify as well as to remove phosphorus were evaluated for the application to biological nutrient removal(BNR) process. In the batch-type experiment, simultaneous reactions of phosphorus release and uptake, and also denitrification were observed under anoxic condition with high organic and nitrate loading. However the rate and the degree of P release were lower than that occurred under anaerobic condition. BNR processes composed of anaerobic-anoxic-oxic(AXO), anoxic-anaerobic-oxic(XAO) and anoxic-oxic(XO) were operated in continuous condition. The anoxic reactors in each process received nitrate loading. In the AXO process, P release in anaerobic reactor and the luxury uptake in oxic reactor proceeded actively regardless to nitrate loading. However in XAO and XO processes, P release and luxury uptake occurred only with the nitrate loading less than $0.07\;kg{NO_3}^--N$/kgMLSS-d. With higher nitrate load, P release increased and the luxury uptake decreased. Therefore, it appeared that the application of denitrifying phosphorus-removing bacteria (DPB) to BNR process must first resolve the problem with decrease of luxury uptake of phosphorus in oxic reactor.

• 상하수도학회지
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• 제13권2호
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• pp.89-94
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• 1999

In this study small glass columns with 2.5cm inner diameter and 24.5cm length were used as many as the sample numbers to study the effects of initial pH, temperature, dissolved oxygen concentration, and sediment depth on the release of phosphorus from lake sediment. No phosphorus release occurred at $10^{\circ}C$ with all pHs, and release rate at $25^{\circ}C$ was higher than that at $35^{\circ}C$ with pH 4 and reverse trends were observed at pH 7 and 10. Under all conditions, DO concentrations were decreased and equilibrium was obtained after 4-8 days when phosphorus release started and the Do concentrations were less than 1 mg/l. Sediment depth had little effect on phosphorus release rate. It was found that relation between released SRP(Soluble Reactive Phosphorus) concentration and time was zero order reaction and reaction rate coefficients were obtained. The amount of phosphorus release from lake sediment can be predicted by considering these k values.

• 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.

• 유기물자원화
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• 제28권3호
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• pp.15-26
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• 2020

하수슬러지 소각재에서 인(P)을 회수하기 위해 소각재를 황산 용액으로 추출한 후, 알칼리 물질로 pH를 높이면서 회수되는 인(P)과 불순물인 중금속 함량을 비교하여 최적의 인(P) 회수 조건을 실험하였으며, 이때 산추출액을 재사용하거나, 소각재를 입자크기 별로 구분하였을 때 인(P) 회수효율을 비교하였다. 하수슬러지 소각재로부터 인(P)을 회수하기 위한 조건은 1N 황산 용액으로 L/S비 10, 추출시간 30분으로 하는 것이 최적이었다. 인(P)을 회수하기 위한 적정 pH는 알칼리 물질 첨가량, 회수되는 침전물 내의 중금속 함량 등을 고려하였을 때 pH 5 이전에 생성되는 침전물에서 인(P)을 회수하는 것이 유리한 것으로 판단된다. 소각재 추출액의 재사용율(100, 50%)에 따라 인(P)의 회수율을 각각 14, 21% 증가시켰으나, Zn 함량이 각각 33, 21%, Cu의 함량이 각각 35, 20% 증가되었다. 하수슬러지 소각재를 입자크기별로 4개 구간으로 나누어 실험한 결과 특정 크기 구간의 소각재 만을 인(P) 추출하는데 따른 장점은 없었다. EDTA와 양이온 교환수지 등을 통한 추출액 중의 중금속 제거 효과는 크지 않았다.

• 한국물환경학회지
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• 제25권6호
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• pp.916-921
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• 2009

This study was aimed to both enhance the fluoride removal and to reduce the phosphorus removal in treating semiconductor wastewater using $Ca(OH)_2$ at low pH so as to facilitate struvite crystallization reaction. The struvite crystallization could be introduced after fluoride removal by retaining the phosphorus source. As the results, the method applied in this study achieved high fluoride removal efficiency (about 91%) with retardation of phosphorus removal at pH 4, compared to conventional methods where the removal of fluoride and phosphorus were done at pH 11. Therefore, the fluoride removal at low pH would contribute to the enhancement of nitrogen and phosphorus removals in a consecutive struvite crystallization reactor. Treatment of semiconductor wastewater at low pH using $Ca(OH)_2$ also had lower (about 20%) water content of precipitated sludge compared to conventional method. As the molar ratio of Ca to F increased the removal efficiencies of fluoride and phosphorus increased. Although the amount of seed dosage didn't affect the removal of fluoride and phosphorus, its increase reduced the water content of precipitated matter. Finally, considering consecutive struvite reaction, the optimum condition for the removal of fluoride and phosphorus was as follow: pH: 4, the molar ratio of Ca:F: 1:1.