• 대한환경공학회지
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• 제28권10호
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• pp.1055-1064
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• 2006

본 연구소에서는 혐기성 입상슬러지를 충진한 UASB 반응기와 탄소섬유를 충진한 배양기를 조합하여 아주 느린 성장특성을 가진 혐기성 암모늄 산화균의 배양을 시도하였다. 연속배양 180일 이후, 유입질소부하가 0.6 kg $N/m^3-d$였을 때, 평균 질소전환율은 0.54 kg $N/m^3-d$로 나타났다. 검은 혐기성 입상슬러지는 연속배양시간이 지남에 따라 갈색과 붉은 색으로 변화되었으며, anammox 반응기는 붉은색 입상슬러지가 많을수록 높은 활성도를 나타내었다. 따라서, 붉은색 입상슬러지를 채취하여 분자생물학적 방법을 이용하여 미생물 군집구조를 분석하였다. 클로닝 및 계통분류학적 분지도 작성 결과, anammox UASB 반응조의 붉은색 입상슬러지에서 발견된 미생물 종류는 anammox 미생물과 더불어 문단위의 4가지 다른 미생물, Proteobacteria, Acidobacteria, Chlorobi와 Chloroflexi로 나타났다. Anammox UASB 반응조내의 붉은색 입상슬러지에서는 clone의 개수를 기준으로 anammox 미생물이 약 25%가 존재하였고 $\beta$-proteobacteria가 우점하고 있는 양상을 보여주었으며, 본 연구의 클로닝 정보와 AMX368 FISH 탐침자를 이용해 in silico 실험을 수행한 결과 AMX368과 정확히 들어맞는 anammox 미생물 clone 하나와 하나의 염기서열이 변이를 일으킨 11개의 anammox 미생물 clone을 확인할 수 있었다. 사상균 형태의 Chloroflexi는 혐기조건 입상 슬러지의 형성과 관련이 있는 것으로 판단되었다. FISH 수행결과, anammox 미생물은 붉은색 입상 슬러지에 우점하고 있는 것으로 나타났다.

• Environmental Engineering Research
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• 제13권4호
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• pp.210-215
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• 2008

The present study investigates the effect of oxidation-reduction potential (ORP) and organic compounds on specific anaerobic ammonium oxidation activity (SAA) using batch experiments. The batch tests were based on the measurement of nitrogen gas production. The relationship between ORP and dissolved oxygen (DO) concentration was found to be ORP (mV) = 160.38 + 68 log [$O_2$], where [$O_2$] is the DO concentration in mg/L. The linear relationship obtained between ORP and SAA ($R^2$ = 0.99) clearly demonstrated that ORP can be employed as an operational parameter in the Anammox process. At ORP value of -110 mV, the SAA was $0.272{\pm}0.03\;g\;N_2-N\;(g\;VSS)^{-1}\;d^{-1}$. The investigation also revealed inhibitory effect of glucose on the SAA while acetate concentration up to 640 mg COD/L (corresponding to 10 mM) had stimulating effect on the SAA. However, acetate concentration beyond 640 mg COD/L had inhibitory effect on the Anammox activity. The results indicated that nitrogen rich wastewaters containing low level organic matter could be better treated by Anammox microorganisms in real-world conditions after some acidification process.

• 상하수도학회지
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• 제25권2호
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• pp.223-230
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• 2011

An electrolytic oxidation process was applied to remove odorous compounds from non-point odor sources including wastewater pipelines and manholes. In this study, a distance between the anode and the cathode of the electrolytic process was varied as a system operating parameters, and its effects on odor removal efficiencies and reaction characteristics were investigated. Odor precursors such as sediment organic matters and reduced sulfur/nitrogen compounds were effectively oxidized in the electrolytic process, and a change in oxidation-reduction potential (ORP) indicated that an stringent anaerobic condition shifted to a mild anoxic condition rapidly. At an electrode distance of 1 cm and an applied voltage of 30 V, a system current was maintained at 1 A, and the current density was 23.1 $mA/cm^{2}$. Under the condition, the removal efficiency of hydrogen sulfide in gas phase was found to be 100%, and 93% of ammonium ion was removed from the liquid phase during the 120 minute operating period. Moreover, the sulfate ion (${SO_4}^{2-}$) concentration increased about three times from its initial value due to the active oxidation. As the specific power consumption (i.e., the energy input normalized by the effective volume) increased, the oxidation progressed rapidly, however, the oxidation rate was varied depending on target compounds. Consequently, a threshold power consumption for each odorous compound needs to be experimentally determined for an effective application of the electrolytic oxidation.

• 한국물환경학회지
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• 제34권1호
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• pp.121-131
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• 2018

Domestic sewage treatment plants (STPs) consume about 0.5 % of total electric energy produced annually, which is equivalent to 207.7 billion Korean won per year. To minimize the energy consumption and as a way of mitigating the depletion of energy sources, the sewage treatment strategy should be improved to the level of "energy positive". The core processes for the energy positive sewage treatment include A-stage for energy recovery and B-stage for energy-efficient nitrogen removal. The integrated process is known as the A/B-process. In A-stage, chemically enhanced primary treatment (CEPT) or high rate activated sludge (HRAS) processes can be utilized by modifying the primary settling in the first stage of sewage treatment. CEPT utilizes chemical coagulation and flocculation, while HRAS applies returned activated sludge for the efficient recovery of organic contents. The two processes showed organic recovery efficiencies ranging from 60 to 70 %. At a given recovery efficiency of 80 %, 17.3 % of energy potential ($1,398kJ/m^3$) is recovered through the anaerobic digestion and combustion of methane. Besides, anaerobic membrane bioreactor (AnMBR) can recover 85% of organic contents and generate $1,580kJ/m^3$ from the sewage. The recovered energy is equal to the amount of energy consumption by sewage treatment equipped with anaerobic ammonium oxidation (ANAMMOX)-based B-stage, $810{\sim}1,620kJ/m^3$. Therefore, it is possible to upgrade STPs as efficient as energy neutral. However, additional novel technologies, such as, fuel cell and co-digestion, should be applied to achieve "energy positive" sewage treatment.

• Journal of Microbiology and Biotechnology
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• 제22권7호
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• pp.1005-1014
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• 2012

The understanding of the relationship between ammonia-oxidizing bacteria (AOB) communities in activated sludge and the operational treatment parameters supports the control of the treatment of ammonia-rich wastewater. The modifications of treatment parameters by alteration of the number and length of aerobic and anaerobic stages in the sequencing batch reactor (SBR) working cycle may influence the efficiency of ammonium oxidation and induce changes in the AOB community. Therefore, in the research, the impact of an SBR cycle mode with alternating aeration/mixing conditions (7 h/1 h vs. 4 h/5.5 h) and volumetric exchange rate (n) on AOB abundance and diversity in activated sludge during the treatment of anaerobic sludge digester supernatant at limited oxygen concentration in the aeration stage (0.7 mg $O_2/l$) was assessed. AOB diversity expressed by the Shannon-Wiener index (H') was determined by the cycle mode. At aeration/mixing stage lengths of 7 h/1 h, H' averaged $2.48{\pm}0.17$, while at 4 h/5.5 h it was $2.35{\pm}0.16$. At the given mode, AOB diversity decreased with increasing n. The cycle mode did not affect AOB abundance; however, a higher AOB abundance in activated sludge was promoted by decreasing the volumetric exchange rate. The sequences clustering with Nitrosospira sp. NpAV revealed the uniqueness of the AOB community and the simultaneously lower ability of adaptation of Nitrosospira sp. to the operational parameters applied in comparison with Nitrosomonas sp.

• 한국물환경학회지
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• 제21권5호
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• pp.477-483
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• 2005

Anammox (Anaerobic Ammonium Oxidation) bacteria is recently discovered microorganism which can oxidize ammonium to nitrogen gas in the presence of nitrite under anaerobic conditions. The anammox process can save an energy for nitrification and need not require a carbon source for denitrification, however, the start-up periods takes a long time more than several months due to the long doubling time (approximately 11 days). In order to find the effects of seeding microorganisms, hydrazine, and nitrite concentration on the enhancement of the anammox activity, five kinds of microorganisms were selected. Among the several kinds of seeding microorganisms, the granule from acclimated microorganisms treating high concentration of ammonia nitrogen (A-1) and sludge from piggery wastewater treatment plant (A-2) were found to have a high anammox activity. In the case of A-1, the maximum nitrogen conversion rate represented 0.4 mg N/L-hr, and the amount of nitrite utilization was high compared to those of other seeding microorganisms. The A-4 represented a higher nitrogen conversion rate to 0.7 mg N/L-hr although the ammonium concentration in the serum bottle was high as 200 mg/L. Meanwhile, the anaerobic granule from UASB reactor treating distillery wastewater showed a low anammox activity due to the denitrification by the remained carbon sources in the granule. Hydrazine, intermediate product in anammox reaction, enhanced the anammox activity by representing 1.4 times of nitrogen gas was produced in the test bottle than that of control, when 0.4 mM of $N_2H_4$ was added to serum bottle which contains 5 mM of nitrite. The high concentration of nitrite (10 mM) resulted in the decrease of the anammox activity by showing lower production of nitrogen gas compared to that of 5 mM addition of nitrite concentration. As a result of FISH (Florescence In-Situ Hybridization) experiment, the Amx820 probe showed a more than 13% of anammox bacteria in a granule (A-1).

• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.326-332
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• 2018

In this study,the result shows that polyvinyl alcohol-sodium alginate (PVA-SA) gel bead crosslinked with sodium sulfate are better among the different methods by comparing the relative mechanical strength, mechanical strength swelling and expansion coefficient of beads in water. Subsequently, anammox biomass entrapment by PVA-SA gel was introduced into continuous stirred tank reactor (CSTR). After 24 operation days, the nitrogen removal efficiency achieved 60%, while the nitrogen loading rate (NLR) was $0.14kgN/m^3/d$ and the experiment data indicated that PVA-SA gel bead crosslinked with sodium sulfate can be used to initiate anammox process. Furthermore, it is an alternative for culturing anammox in a long-term operation.

• 대한환경공학회지
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• 제28권4호
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• pp.414-420
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• 2006

세정단계를 거치는 혐기성 소화시스템(ADEPT, Anaeorbic Digestion Elutriated Phase Treatment)에서 돈사폐수를 처리한 유출수를 혐기성 암모늄 산화공정(ANAMMOX)에 적용하기 위하여 부분질산화 반응조의 기질로 사용하였다. 중온($35^{\circ}C$)에서 아질산성 질소를 축적하는 조절인자는 용존산소보다는 오히려 HRT, pH, 유리 암모니아(FA)였다. 중탄산의 스트립핑과 완충에 사용된 양을 포함한 중탄산알칼리도의 소모량은 전환된 $NH_4-N$ g당 8.78 g이었다. HRT 1일, DO 농도가 $2.7{\sim}4.4mg/L$의 안정상태에서 부분질산화 반응 유출수의 $NO_2-N/NH_4-N$ 비는 약 $1{\sim}$으로서, 부분질산화-혐기성 암모늄산화 결합공정의 ANAMMOX 반응조의 유입수로서 적합하였다.

• 대한환경공학회지
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• 제31권10호
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• pp.919-926
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• 2009

혐기성 암모늄 산화공정을 안정화시키기 전에 많은 양의 식종 미생물 투여가 필요하므로 혐기성 암모늄 산화균의 농후배양은 실규모의 혐기성 암모늄 산화 반응기를 운영할 때 필수적인 과정이다. 본 연구에서는 활성슬러지 미생물을 식종한 연속 회분식 반응기를 이용하여 혐기성 암모늄 산화균을 농후배양하고, 미생물 군집구조의 변화를 관찰하여 농후배양 결과를 검증하였다. 혐기성 암모늄 산화균의 농후배양은 70일간 시행되었고, 농후배양 후 활성시험에서 $NH_4\;^+$와 $NO_2\;^-$의 기질제거효율이 각각 98.5%와 90.7%로 관찰되어 혐기성 암모늄 산화균의 배양이 성공적으로 수행된 것으로 판단되었다. 계통분류학적 분지도 작성 결과, 다양하였던 Planctomycetes 문(phylum)의 미생물 군집구조가 농후배양 이후에 현저하게 단순해졌다는 것이 밝혀졌다. 농후배양 이후 발견된 36개의 clone들 모두가 혐기성 암모늄 산화균이었으며, Candidatus Brocadia (36%) 와 Candidatus Anammoxoglobus (64%) 속(genus)에 속하였다. RTQ-PCR (real-time quantitative PCR)을 통해 혐기성 암모늄 산화균을 정량한 결과, 혐기성 암모늄 산화 상향류식 연속 배양기에서 1년 이상 선택 배양된 붉은색 혐기성암모늄 산화 입상 슬러지에 비해 혐기성 암모늄 산화균의 16S rDNA 농도가 74.8%인 것으로 나타났다. 상기의 분자생물학적 분석을 통해 70일간 농후배양된 활성슬러지가 혐기성 암모늄 산화 실용화 공정의 접종 미생물로 활용 가능할 것으로 판단되었다.

• 한국해양학회지:바다
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• 제26권2호
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• pp.110-123
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• 2021

시화호 인근 연안 퇴적물에서 유기물 분해 특성, 퇴적물로부터의 영양염 용출 및 주요 조절요인을 파악하기 위해 공극수와 퇴적물 내 지화학 성분, 혐기성 유기물 분해율, 황산염 환원율 및 저층 영양염 용출률을 측정하였다. 연구정점은 소래포구 인근 정점(E0), 송도갯벌 정점(E1), 오이도 선착장 부근 정점(E3), 시화 조력발전소 수문 앞 정점(E5)으로 선정하였다. 유기탄소와 공극수 내 암모니아, 인산염 농도는 정점 E0에서 가장 높게 나타났으며, 외측 해역(정점 E1, E3, E5)으로 갈수록 점진적으로 감소하였다. 혐기성 유기물 분해율과 황산염 환원율은 정점 E0에서 각각 260.6 mmol C m^-2 d^-1와 91.4 mmol S m^-2 d^-1로 외측 정점들보다 각각 4-9배, 6-54배 높게 나타났다. 혐기성 유기물 분해에서 황산염 환원이 차지하는 비율은 정점 E3, E5에서 11-23%로 미미한 것으로 나타났으나, 정점 E0, E1에서는 47-70%로 황산염 환원에 의해 혐기성 유기물 분해가 주도되는 것으로 나타났다. 또한, 혐기성 유기물 분해율과 황산염 환원율은 용존 유기탄소와 상관성이 매우 높은 것으로 나타났다(r² = 0.795, 0.777). 한편, 정점 E0, E1, E3에서 퇴적물로부터 용출된 무기질소와 무기인은 각각 일차생산자가 요구하는 무기질소와 무기인의 120-510%와 26-178%를 공급하는 것으로 나타났다. 이상의 결과들은, 시화호 인근 연안 퇴적물 내 유기물 분해는 이용 가능한 용존 유기탄소의 공급에 의해 조절되고 있으며, 과도한 유기물 분해는 저층 영양염 용출을 촉진시켜 부영양화를 야기할 수 있음을 의미한다.