• 한국물환경학회지
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• 제24권1호
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• pp.30-35
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• 2008

In this study, we investigated the nitrification/denitrification rate and classification of output nitrogen of a sequencing batch reactor (SBR) system with the variation of COD loads ; COD loads of 0.3, 0.4, 0.6, 0.7, 0.8, 1.0 and $1.2kgCOD/m^3{\cdot}d$ were tested to determine the optimum conditions for the operation of the SBR and increase its nitrogen removal efficiency. As the COD loads increased, the nitrification rate at aerobic(I) period and the denitrification rate at anoxic(I) period were decreased. With the variation of COD loads, the amounts of nitrogen removed in the clarified water effluent were 63.9, 54.2, 34.7, 22.5, 13.7, 12.5 and 26.5 mg/cycle, respectively. The amounts of nitrogen removed during the sludge waste process were 19.5, 26.6, 41.0, 47.3, 58.1, 72.4 and 88.1 mg/cycle, respectively. The amounts of nitrogen removed by denitrification were 66.8, 69.3, 68.9, 56.5, 39.5, 7.3 and 0.0 mg/cycle, respectively, indicating that COD load more than $0.7kgCOD/m^3{\cdot}d$ decreases the amounts of denitrified nitrogen. The nitrogen mass balances were calculated as the percentages of nitrogen removed in the clarified water effluent or by denitrification and sludge waste processing in each cycle of SBR operation and were 99.0, 98.5, 95.4, 82.1, 73.0, 60.5 and 74.8% for COD loads of 0.3, 0.4, 0.6, 0.7, 0.8, 1.0 and $1.2kgCOD/m^3{\cdot}d$, respectively.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.467-470
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• 2003

Leaking underground storage tanks are a major source of groundwater contamination by petroleum hydrocarbons. Aerobic bioremediation has been highly effective in the remediation of many fuel releases. However, Bioremediation of aromatic hydrocarbons in groundwater and sediments is ofen limited by the inability to provide sufficient oxygen to the contaminated zones due to the low water solubility of oxygen. Nitrate can also serve as an electron acceptor and results in anaerobic biodegradation of organic compounds via the processes of nitrate reduction and denitrification. Because nitrate is less expensive and more soluble than oxygen. it may be more economical to restore fuel-contaminated aquifers using nitrate rather than oxygen. And denitrifying bacteria are commonly found in the subsurface and in association with contaminated aquifer materials. These studies have shown that BTEX and MTBE can be degraded by the nitrate-amended microcosms under aerobic and anaerobic conditons. Biodegradation of the toluene and ethylbenzne compounds occurred very quickly under denitrifying conditions. MTBE, benzene and p-xylene were recalcitrant under denitrifying conditions in this study, But finally Biodegradaton was observed for all of the test compounds.

• KSBB Journal
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• 제17권1호
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• pp.80-87
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• 2002

유기물 제거뿐만 아니라 안정적으로 질소와 인의 동시 제거를 위한 순환식 생물막 반응기를 제작, 운전하여 최적의 운전 인자를 도출하고, 질소 제거의 텃 번째 단계인 질산화 및 뒤이은 탈질에 관여하는 미생물들의 군집 구조 분석을 수행하였다. 유기물 제거와 질소와 인의 동시 제거를 위한 순환식 생물막 반응기는 143일 동안 운전되었다. 이 결과 $COD_{cr},\;BOD_5$, SS의 경우 각각 88, 88, 97%의 평균 제거효율을 보였다 이 기간 중 질산화율은 약 96% 정도로 유입 ${{NH_4}^{+}}_{-}N$의 대부분이 제거됨을 보였다. 하지만 탈질율은 평균 45% 정도로 나타났다. 반응기로 유입되는 총 인의 경우 약 44%가 제거되었다. 질소제거의 첫 번째 단계인 질산화가 일어나는 호기성 반응조 내 질산화 미생물의 경우 FISH 관찰 결과, 주요 암모니아 산화균 및 아질산 산화균으로는 Nitrosomonas spp.와 Nitrospira sap.가 관찰되었다. 또한 탈질 반응이 일어나는 준혐기성 반응조에서는 Rhodobacter, Rhodovulum, Roseebacter 그리고 Paracoccus 속에 속하는 탈질 미생물들이 전체 미생물의 약 10~20% 정도를 차지하며 분포하였다.

• 한국물환경학회지
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• 제22권2호
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• pp.222-229
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• 2006

The treatment performance and operational parameters of a tertiary wastewater treatment process a biological filtration system were investigated. The biological filtration system consisted of a nitrification filter (Fiter 1) and a polishing filter with anoxic and aerobic parts (Filter 2). SS, T-C-BOD, and T-N in effluent were kept stable at less than 3, 5 mg/L, and 5 mgN/L, respectively, under a HRT in Filter (filter-bed) of 0.37~2.3 h. T-N at the outlet of Filter 2 were about 1~5 mgN/L under the condition of LV of 50~202 m/d. In Filter 2, denitrification was accomplished under LV of 50~168 m/d in a 1 m filter-bed. However, the denitrification capacity reached the maximum when the linear velocity was increased to 202 m/d. Relationship between increase in microorganism and headloss was clearer in Filter 2. As a result, the denitrification rate increased from 1.0~2.3 kgN/($m^3-filter-bed{\cdot}d$) as the headloss increased. The COD removal rate was 6.0~9.6 kgCOD/($m^3-filter-bed{\cdot}d$) when operated with Filters 1 and 2. These results mean that captured bacteria contributed a part of COD consumption and denitrification. The maximum nitrification and denitrification rate was 0.5 and 4 kgN/($m^3-filter-bed{\cdot}d$) in Filter 1 and 2.The ratio of backwashing water to the treated water was about 5~10 %. In Filter 1, wasted sludge in backwashing was only 0.7~5.3 gSS/($m^3$-treated water). In Filter 2, added methanol was converted into sludge and its value was 8.0~24 gSS/($m^3$-treated water). These results proved that this process is both convenient to install as tertiary treatment and cost effective to build and operate.

• 한국환경과학회지
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• 제12권4호
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• pp.427-437
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• 2003

An evaluation of the application of SBR and biofilm en small sewerage system was conducted. A newly developed small sewerage system, using SBR, was successfully applied to the nutrient treatment using municipal wastewater. The system was consisted of 6 compartments. Two systems, with SBR (A type) or without SBR (B type), were compared by several parameters (COD, SS, T-N, NH$_4$$\^$+/-N, NO$_3$$\^$-/-N, NO$_2$$\^$ -/-N, alkalinity, pH, DO) in all experimental periods. Also, the time variation of several parameters (DO, pH, NH$_4$$\^$+/-N, NO$_3$$\^$-/-N NO$_2$$\^$-/-N) was examined in a SBR applied sewerage system. T-N removal efficiency of B type Was higher than that Of A type by the effect of nitrification and denitrification even though the COD removal efficiencies were similar. In aeration stage, the pH was decreased from 6.4 to 6.3 within 1 h and increased to 6.65 at the end of aerobic stage, and pH was decreased to 6.2 in non-aeration stage, and these phenomena were explained. The effects of nitrification and denitrification were compared in A type and B type sewerage system, and the typical nitrification and denitrification were observed in B type sewerage system.

• 상하수도학회지
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• 제22권2호
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• pp.179-182
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• 2008

The KIDEA process, occurred in single reactor, is operated by three consequential steps, i.e., aerobic, settling, and discharge while introducing wastewater into the bottom of reactor continuously. It could accomplish biological oxidation (BOD), nitrification, denitrification (T-N), phosphate removal (T-P), and solid separation (SS) through the operational mode mentioned. Especially, this system has removed the T-P by wasting certain amount of sludge at the end of aeration phase during 5~10 minutes and not returned the activated sludge into the reactor, that is, no RAS (Return Activated Sludge). All running mode and instrumentation were controlled by the PLC equipment automatically. In this study, therefore, we have evaluated T-P removal efficiency and moisture content (MC) performance under the different excess sludge wasting mode. T-P track study and MC with TS concentration were analyzed during aerobic and settling phase. It has revealed that there was no significant difference of released T-P concentration between the first case which waste the sludge at the end of aerobic phase (0.2mg/L) and the second case which waste the sludge at 40 min of settling phase (0.25mg/L). Also, dewatering duration and MC have decreased 1.7% when TS concentration was increased from 0.31% to 0.5% during aerobic condition. Hence, it has concluded the system performance was less influenced by the operation time change of PLC program.

• 대한환경공학회지
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• 제30권2호
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• pp.199-206
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• 2008

동시 질산화 탈질은 낮은 DO 농도로 유지되는 동일한 반응조에서 질산화 반응과 탈질 반응이 동시에 발생함을 의미한다. 동시 질산화 탈질 반응을 모사할 수 있는 몇몇 수학적 모델들이 개발되었지만, 모델 구조가 복잡하거나 모델을 적용하기 위한 다양한 제반 지식을 얻어야만 정확한 결과를 얻을 수 있어 범용적인 모델 적용에 한계점이 있는 단점이 있었다. 이와 같은 문제를 해결하기 위해, 동시 질산화 탈질 반응이 반응기 내 DO 농도의 부분적 부재로 발생한다는 가정 하에, 만약 활성슬러지모델을 사용하여 동시 질산화 탈질 반응의 거동을 해석할 수 있다면, 모델의 구조가 다른 개발된 모델들보다 복잡하지 않고, 다양한 운전 조건에서 모델이 활용될 수 있을 것으로 판단하였다. 하지만 기존의 활성슬러지 모델로는 호기 조건에서 발생하는 탈질 반응을 표현하기 어려운 점이 있기 때문에, 본 연구에서는 활성슬러지 모델을 수정함으로써 동시 질산화 탈질 반응을 해석하고자 하였다. 활성슬러지 모델 No.1(ASM1)이 선택이 되어 탈질 반응식이 수정되었으며, 수정된 ASM1의 시뮬레이션 결과는 측정값의 거동을 잘 모사하였다. 이를 통해 수정된 ASM1은 실험 결과에 기반하여 구한 ${\eta}_g$의 값과 호기 조건에서의 탈질 반응을 모사하기 위해 수정된 Monod 식의 영향으로 모델의 구조가 본 연구의 실험 결과에서 확인된 동시 질산화 탈질 반응을 해석할 수 있도록 구성되었다고 사료된다.

• 대한환경공학회지
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• 제38권2호
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• pp.79-86
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• 2016

본 연구의 목적은 RO 농축수 내 TDS 제어에 따른 고농도 질산성 질소의 효율적인 생물학적 처리에 있다. 실험실 규모의 실험에서는 연속회분식 반응기를 이용하여 연구를 수행하였으며 TDS의 주입조건에 따른 비탈질율, 비산소소비율 분석을 수행하였다. 연구결과, 연속회분식 반응기를 이용한 운전에 따라 탈질 공정 내 고농도 TDS 주입에 따라 탈질 반응이 지연되어 SDNR이 감소하는 것으로 나타났으며 미생물 활성도가 또한 감소하는 것으로 나타났다. 따라서 질산성 질소의 원활한 처리를 위하여 TDS 제어가 수반되어야 하며 특히, $Ca^{2+}$의 중점적인 처리가 필요할 것으로 판단된다. 또한 본 연구를 통하여 도출된 SDNR, SOUR 값은 호기성 그래뉼 슬러지를 이용한 RO 농축수의 생물학적 처리를 위한 공정 설계인자로 활용이 가능할 것으로 판단된다.

• 한국환경농학회지
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• 제29권3호
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• pp.221-226
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• 2010

축산폐수는 고농도의 유기물 및 질소를 함유하고 있으므로 적절한 처리 방법이 요구된다. 본 연구는 황을 이용한 독립영양 탈질 방법으로 질산성 질소에서 질소가스로의 탈질이 아닌 아질산성질소에서의 황산화 탈질을 연구하였으며 탈질 미생물의 최적 성장 조건을 찾고자 하였다. 초기 알칼리도가 충분한 조건에서는 아질산성질소 탈질 저해가 관찰되지 않았으며 실험온도가 $20^{\circ}C$인 경우에도 $30^{\circ}C$와 비교할 때 큰 저해 없이 탈질이 진행되었다. 하지만 초기 아질산성질소의 농도 300 mg/L 이상에서 lag phase가 늘어나 기질저해가 나타났다. 알칼리도가 충분하지 않은 조건에서 질산성질소의 탈질효율은 10%인 반면 아질산성질소의 탈질의 95% 이상이었다. 산소가 존재할 경우 산소를 이용하여 탈질이 이루어지지 않았음에도 불구하고 황산화 미생물이 산소를 이용하여 황산염의 농도가 증가하였다. 아질산성질소 탈질 시 알칼리도의 소모가 관찰되었으나 질산염 탈질시 보다 알칼리도의 소모가 적었으며 황산염 생성 또한 적었다. 황이용 아질산성 질소 탈질은 외부탄소원의 추가적인 주입 없이 저렴한 황입자를 이용하며 질산성질소 황산화 탈질의 단점인 알칼리도 파괴, 황산염이온 생성의 단점을 보완할 수 있는 효과적인 탈질 방법이 될 것으로 기대된다.

• Membrane and Water Treatment
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• 제11권1호
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• pp.79-85
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• 2020

A single-stage deammonification with a sequencing batch reactor (SBR) that simultaneous nitritation, anaerobic ammonia oxidation (anammox), and denitrification (SNAD) occur in one reactor has been widely applied for sidestream of wastewater treatment plant. For the stable and well-balanced SNAD, a feeding strategy of influent wastewater is one of the most important operating factors in the single-stage deammonification SBR. In this study, single-stage deammonification SBR (working volume 30L) was operated to treat a high-strength ammonium wastewater (1200 mg NH₄⁺-N/L) with different feeding strategies (single feeding and nine-step feeding) under the condition without COD. Each cycle of the step feeding involved 6 sub-cycles consisted of aerobic and anoxic periods for partial nitritation (PN) and anammox, respectively. Contrary to unstable performance in the single feeding, the step feeding showed better deammonification performance (0.565 kg-N/m³/day). Under the condition with COD, however, the nitrogen removal rate (NRR) decreased to 0.403 kg-N/m³/day when the Nine-step feeding strategies had an additional denitrification period before sub-cycles for PN and anammox. The NRR was recovered to 0.518 kg-N/m³/day by introducing an enhanced multiple-step feeding strategy. The strategy had 50 cycles consisted of feed, denitrification, PN, and anammox, instead of repeated sub-cycles for PN and anammox. The multiple-step feeding strategy without sub-cycle showed the most stable and excellent deammonification performance: high nitrogen removal efficiency (98.6%), COD removal rate (0.131 kg-COD/m³/day), and COD removal efficiency (78.8%). This seemed to be caused by that the elimination of the sub-cycles might reduce COD oxidation during aerobic condition but increase the COD utilization for denitrification period. In addition, among various sensor values, the ORP pattern appeared to be applicable to monitor and control each reaction step for deammonification in the multiple-step feeding strategy without sub-cycle. Further study to optimize the number of multiple-step feeding is still needed but these results show that the multiple-step feeding strategy can contribute to a well-balanced SNAD for deammonification when treating high-strength ammonium wastewater with COD in the single-stage deammonification SBR.