• 대한환경공학회지
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• 제22권1호
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• pp.141-148
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• 2000

본 연구에서는 EBPR(enhanced biological phosphorus removal)공정에서 인 방출에 대한 유기물 및 질산염의 영향을 혐기성 조건에서 회분식 실험으로 관찰하였다. 본 실험에서 사용한 슬러지는 축산폐수를 처리하기 위한 SBR(sequencing batch reactor) 공정의 호기성 상태에서 채취하였다. 유기물인 FSW(fermented swine wastewater), acetate, propionate, 도시하수 및 methanol의 인 방출 속도는 각각 6.19, 5.99, 1.52, 1.2 및 $1.03mgP/gVSS{\cdot}hr$이었다. Acetate 및 FSW의 인 방출 속도는 propionate, methanol 및 도시하수보다 4~5배 더 크게 관찰되었다. 따라서 혐기성 조건에서 인 방출 속도는 주입되는 유기물의 종류에 많은 영향을 받는다. 혐기성 조건에서 인 방출은 질산염의 농도에 의해 커다란 영향을 받았다. Acetate, propionate 및 FSW와 비교하여, 유기물로서 주입된 methanol 및 도시 하수인 경우 인 방출은 질산염이 거의 완전히 제거된 후 관찰되었다. Acetate, propionate 및 FSW가 주입 된 경우의 인 방출 속도는 methanol 및 도시하수가 주입되었을 때보다 질산염의 영향을 더 적게 받았다.

• 한국환경과학회지
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• 제14권9호
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• pp.861-871
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• 2005

This study was carried out to get more operational characteristics of Anoxic(anaerobic)-Oxic-Anoxic-Oxic $(AO)_2$ sequencing batch biofilm reactors (SBBRs) at the low TOC concentration, The operating time in anoxic (anaerobic) time to oxic time was I : I. Experiments were conducted to find the effects of the aeration time distribution on the organic matters and nutrients removal. Three lab-scale reactors were fed with synthetic wastewater based on glucose as carbon source. During studies, the operation mode was fixed. The first aeration time to the second aeration time in SBBR-I was 2 : 3, and those in SBBR-2 and SBBR-3 were I : 4 and 3 : 2, respectively. The organic removal efficiency didn't show large difference among three reactors of different aeration time distribution. However, from these study results, the optimum aeration time distribution in the first and the second aeration time for biological nutrient removal was shown as 3 : 2. The release of phosphorus was inhibited at the second non-aeration period because of the low TOC concentration and the nitrate produced by the nitrification at the first aeration period.

• Membrane and Water Treatment
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• 제3권2호
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• pp.133-140
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• 2012

The overall performance of BNR-MBR, so-called Anoxic-Anaerobic-Aerobic Membrane Bioreactor ($A^3$-MBR), developed for nutrient removal was studied to determine the efficiencies and mechanisms under different solid retention time (SRT). The reactor was fed by synthetic high-rise building wastewater with a COD:N:P ratio of 100:10:2.5. The results showed that TKN, TN and phosphorus removal by the system was higher than 95%, 93% and 80%, respectively. Nitrogen removal in the system was related to the simultaneous nitrification-denitrification (SND) reaction which removed all nitrogen forms in aerobic condition. SND reaction in the system occurred because of the large floc size formation. Phosphorus removal in the system related to the high phosphorus content in bacterial cells and the little effects of nitrate nitrogen on phosphorus release in the anaerobic condition. Therefore, high quality of treated effluent could be achieved with the $A^3$-MBR system for various water reuse purposes.

• 한국물환경학회지
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• 제22권3호
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• pp.566-571
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• 2006

A sequencing batch biofilm reactor (SBBR) operated with a cycle of anaerobic - aerobic - anoxic - aerobic has been evaluated for the nutrient removal characteristics. The sponge-like moving media was filled to about 10% of reactor volume. The sewage was the major substrate while external synthetic carbon substrate was added to the anoxic stage to enhance the nitrogen removal. The operational results indicated that maximum T-N and T-P removal efficiencies were 97% and 94%, respectively were achieved, while COD removal of 92%. The observations of significant nitrogen removal in the first aerobic stage indicated that nitrogen removal behaviour in this SBBR was different to conventional SBR. Although the reasons for aerobic nitrogen removal has speculated to either simultaneous nitrification and denitrification or anoxic denitrification inside of the media, further researches are required to confirm the observation. The specific oxygen uptake rate (SOUR) test with biofilm and suspended growth sludge indicated that biofilm in SBBR played a major role to remove substrates.

• 한국물환경학회지
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• 제27권5호
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• pp.646-653
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• 2011

The combined system of sequencing batch biofilm reactor (SBBR) and membrane SBR (MSBR) was operated with sewage to evaluate the COD utilization for biological nutrient removal (BNR). The SBBR was operated for nitrification reactor, while denitrifying PAO (dPAO) was cultivated in MSBR with anaerobic-anoxic operation. In the SBBR and MSBR system, the enhanced biological phosphorus removal (EBPR) was successfully achieved with higher N removal. The COD utilization in combined SBBR-MSBR system was significantly reduced compared to ordinary BNR (up to 3.1 g SCOD/g (N+P) and 1.6 g SCOD/g (N+P) with different C/N/P ratio). The results suggest that a dPAO process could effectively reduce carbon energy (=COD) requirement. The combination of oxic-SBBR and anaerobic-anoxic MSBR for dPAO utilization could be an attractive alternative to upgrade the process performance in weak sewage.

• 한국물환경학회지
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• 제27권6호
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• pp.754-759
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• 2011

A sequencing batch reactor (SBR) was operated under different pH conditions to better understand the influence of pH to granulation in enhanced biological phosphorus removal systems. Granules from the SBR were also investigated using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Considerable decreases in the amount of phosphorus released per substrate provided under anaerobic conditions and the content of biomass polyphosphate under aerobic conditions were observed when pH was changed from 7.5 to 7.0, followed by 6.5. Aerobic granulation was also observed at pH 7.0. A number of bacteria with the typical morphological traits of tetrad-forming organisms (TFOs) were observed at pH 7.0, including large members of cluster. Filamentous bacteria were also there in large numbers. The occurrence and growth of granules were further enhanced at pH 6.5. A SEM analysis showed that the aerobic granules had a compact microbial structure with shaperical shape and morphologically consisted of aggregates of small coccoid bacteria and filamentous bacteria encapsulated by extracellular polymeric substance. The main material ions identified by EDX moreover revealed that the structural materials for polyphosphate in the granules include phosphorus, potassium and calcium. Therefore, these results strongly suggested that PAOs are a dominant population in the microbial community of the aerobic granules.

• 한국환경농학회지
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• 제25권1호
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• pp.40-46
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• 2006

This study was initiated to evaluate the inhibitory effect of selected heavy metals on the growth of Acinetobacter sp. Down as one of the phosphorus accumulating microorganisms (PAO) involved in the enhanced biological phosphorus removal (EBPR) process of the wastewater treatment plant. Acinetobacter sp. was initially selected as a starting model microorganism and was grown under aerobic condition for this experiment. The heavy metals selected and investigated in this study were cadmium (Cd), copper (Cu), mercury (Hg), nickel (Ni), and zinc (Zn). Median $(IC_{50})$ and threshold $(IC_{10})$ inhibitory concentrations for Cd, Cu, Hg, Ni, and Zn were 2.95 and 1.45, 4.92 and 2.53, 0.03 and 0.02, 1.12 and 0.43, 14.84 and 5.46 mg $L^{-1}$, respectively. We demonstrated that most of heavy metals tested in the experiment inhibited the growth of Acinetobacter sp. in the range of predetermined concentrations. Based on the data obtained from the experiment, Hg was the most sensitive to Acinetobacter sp., then Ni, Cd, Cu, and Zn in order.

• 한국환경농학회지
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• 제29권2호
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• pp.189-196
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• 2010

The removal of phosphorus (P) in the wastewater is essential for the prevention of eutrophication in the river and stream. This study was initiated to evaluate the effect of the various heavy metals on the growth and P removal capacity of Pseudomonas sp., which was well known as phosphorus accumulating microorganism(PAO's) in the EBPR(Enhanced Biological Phosphorus Removal) process. The five heavy metals used in the study were Cu, As, Zn, Ni, and Cd. The growth rate of Pseudomonas sp. was the greatest at $25^{\circ}C$, but the removal efficiency of P was the highest at $30^{\circ}C$. The $IC_{50}$ (median Inhibition Concentration) values of Pseudomonas sp. for the Cu, As, Zn, Ni, and Cd were 2.35, 11.04, 1.80, 4.92, and 0.24 mg/L, respectively. Therefore, it appears that the sensitivity of the heavy metals to Pseudomonas sp. was in the following order: Cd> Zn> Cu> Ni> AS. Also, the P removal efficiencies by Pseudomonas sp. were correspondingly decreased as the concentrations of heavy metals were increased.

• 대한환경공학회지
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• 제29권2호
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• pp.197-204
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• 2007

이 연구는 EBPR(enhance biological phosphorus removal)의 혐기조건, 호기/무산소 조건 사이의 상호작용을 알아보고 인의 제거 속도와 인 제거에 미치는 영향인자들을 Batch-test로 조사하였다. 실험결과 무산소단계에서 인의 흡수율은 호기 단계보다 50% 정도 낮았고, 인 방출과 인 흡수의 상관관계는 다른 논문들에 비하여 낮았으며, 계수 b는 높았다. Batch-test의 측정 결과 다른 논문들에 비하여 인 방출과 인 흡수의 상관관계$(R^2=0.557)$는 낮았고 계수b (b=8.4049)는 높았다. 또한, 하수에서 인의 중요한 결합 파트너는 Ca, $Mg^{2+}$, Al, Fe 그리고 $K^+$인데 이 실험 결과 칼륨, 마그네슘 그리고 암모니움은 인과 함께 증감함으로써 인의 방출과 흡수에 밀접한 관계가 있음을 알 수 있었다. 즉, 혐기 단계에서 0.2 mol $K^+Ion$ / mol $PO_4-P$ Ion과 0.21 mol $Mg^{2+}Ion$ / mol $PO_4-P$ ion이 측정되어 인에 대한 칼륨 및 마그네슘의 비율은 1 : 5 정도임을 알 수 있었다.

• 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.