• 한국물환경학회지
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• 제20권1호
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• pp.42-47
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• 2004

This study was accomplished to develope an advanced wastewater treatment process using high MLSS in anoxic tank aimed to improve nutrient removal and to reduce wasting sludge. It was operated with 4 Modes with varing solid concentration and internal recycle ratios. Mode I, II, III was operated 1.0~1.5% MLSS concentration at anoxic tank with 50% sludge recycle rate, however, each internal recycle rate were 100%, 200%, 300% and Mode IV was operated 1.5~2.0% MLSS concentration at anoxic tank with 50% sludge recycle rate and 100% internal recycle rate. The COD removal efficiency didn't show any big difference from Mode I to IV. The average COD removal rate was over than 90%. The T-N removal rate was 73%, the highest rate in all mode. The 36% of SCOD is used for the denitrification and phosphorus release in the anoxic tank. Specific denitrification rate was 3.5mg $NO_3{^-}-N/g$ Mv/hr and denitrification time was 0.7hr. As MLSS concentration is higher in anoxic tank as denitrification time would be shorter. The T-P removal rate was average 70%. The phosphorus release accomplished from the anoxic tank because the anaerobic condition was prevalent in the anoxic due to the prompt completion of denitrification. Sludge production was 0.28 kgVSS/kg $BOD_{removed}$ under the 1.5% MLSS and 17 day SRT. It is prominent result which has 40% sludge reduce comparing with traditional activate sludge system.

• 청정기술
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• 제25권4호
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• pp.302-310
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• 2019

호기조와 혐기/무산소조를 직렬로 연결한 인공습지를 이용하여 크게 오염된 하천수를 처리하였다. 호기조는 자연 공기 배출 시스템을 통하여 공기가 연속적으로 공급되어 호기성 상태가 유지되었다. 인공습지의 성능에 영향을 미치는 최적의 영향인자를 조사하기 위하여 체류시간을 다르게 한 5개의 파일럿 플랜트를 사용하였다. 호기조에서 BOD (biochemical oxygen demand)와 COD (chemical oxygen demand)의 제거율은 1차 반응 속도식을 나타내었고, COD 제거 속도 상수는 BOD보다 약간 낮았다. 온도 의존성은 COD (θ = 1.0079)와 BOD (θ = 1.0083)제거에 대한 값이 거의 동일했으나 T-N 제거의 온도 의존성(θ_N)은 1.0189로 다소 높게 나타났다. SS제거율은 98%로 높았고 수력학적 부하 속도(Q/A)가 증가함에 따라 제거 효율이 증가하는 경향을 보였다. 혐기/무산소조에서 BOD와 COD 제거의 주요 메커니즘은 호기조와 완전히 다르게 나타났다. 혐기/무산소조에서 COD와 COD는 생물학적 탈질을 위한 탄소원으로 공급되었고 T-P는 혐기/무산소조 내의 orthophosphate와 자갈 사이의 양이온 교환에 의해 제거되는 것으로 조사되었다. 인공습지는 여과된 고형물에 의해 막힘 없이 성공적으로 운영되었고 고형물들은 매우 빠르게 연속적으로 분해되었다.

• 상하수도학회지
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• 제16권6호
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• pp.670-678
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• 2002

Since Korean government imposed a stricter regulation on effluent T-N and T-P concentrations from wastewater treatment plant, a new process has to be developed to meet these rules and this process should remove T-N and T-P, economically, from weak wastewater that is typical for Korea's combined sewer system sewage. In this study, a computer simulator, BioWin from EnviroSim, Inc. was used. Three processes - A2/O, Modified Johannesburg, UCT- had been simulated under same operational conditions and a new process - Parallel BNR Process - had been developed based on these simulation results. The Parallel BNR process consists of two rows of reactors: One row has anaerobic and aerobic reactors in series, and the other row has RAS anoxic1 and RAS anoxic2 reactors in series. In order to ensure anaerobic state in anaerobic tank, a part of influent is fed to RAS anoxic1 tank in second row. This process had been simulated under same conditions of other three processes and the simulation results were compared. The results showed that three existing processes could not perform biological phosphorus removal when the average influent was fed at any operation temperatures. However, the Parallel BNR process was found that biological phosphorus removal could be performed when both design and average influent were fed at any operation temperatures. This process showed the T-N concentration in effluent had a maximum value of 15mg/L when design influent was fed at $13^{\circ}C$ and a minimum value of 14mg/L when average influent was fed at $20^{\circ}C$. Also, T-P concentrations had a maximum value of 1.3mg/L when average influent was fed at $20^{\circ}C$ and a minimum value of 1.1mg/L when design influent was fed at $13^{\circ}C$. Based on these results, we found that this process can remove nitrogen and phosphorus biologically under any operational conditions.

• 한국환경보건학회지
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• 제34권6호
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• pp.446-451
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• 2008

In this study, the removal characteristics of organic components and nutrients of sewage taken from the Suwon area were investigated in a lab-scale modified DNR (Daewoo Nutrient Removal) process. The modified DNR process consisted of a sludge denitrification tank, an anaerobic tank, an anoxic tank, an aerobic tank, a secondary anoxic tank and a secondary aerobic tank. The proposed process with the average C/N ratio of 3.5 was performed for the sewage treatment. The results were compared with other existing DNR processes. The organic fractions in sewage were analyzed by measuring the oxygen uptake rate. The resulting removal efficiencies of SS, BOD, COD, TN and TP were 93.1%, 95.5%, 86.1%, 67.8% and 80.6%, respectively.

• Membrane and Water Treatment
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• 제3권2호
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• pp.113-121
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• 2012

Up-flow multi-layer bioreactor (UMBR) is a hybrid system using dual sludge that consists of an up-flow multi-layer bioreactor as anaerobic/anoxic suspended growth microorganisms followed by an aeration tank. The UMBR acts as a primary settling tank, anaerobic/anoxic reactor, thickener which requires low energy due to mixing by up-flow stream. This study focused on using a pilot UMBR plant with capacity of 20-30 $m^3$/day for domestic wastewater in HCMC. HRTs of UMBR and aeration tank were 4.8 h and 7.2 h, respectively. The average MLSS of UMBR ranged from 10,000-13,600 mg/l SS. Internal recycle rate and sludge return were 200-300% and 150-200%, respectively. The results obtained from this study at flow rate of 20 $m^3$/day showed that removal of COD, SS, TKN, N-$NH_4$, T-N, and color were 91%, 87%, 86%, 80%, 91% and 91%, respectively.

• KSBB Journal
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• 제20권4호
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• pp.253-259
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• 2005

본 연구는 고정 생물막을 이용한 혐기/무산소/호기 공정으로 구성된 반응기에서 폴리에틸렌 재질의 표면을 이온빔으로 조사하여 소수성 표면을 친수성으로 만든 표면개질담체를 호기조의 여재로 사용하고 혐기/무산소조의 여재로는 표면 개질을 하지 않은 담체를 사용하여, 외부 탄소원 대신 원수내의 RBDCOD를 탄소원으로 이용하고자 혐기조와 무산소조에 원수를 분할 주입하였을 때 나타나는 유기물 및 T-N 제거 특성을 알아보았다. 혐기/무산소조로의 원수 분배율이 각각 10 : 0, 9 : 1, 8 : 2, 6 : 4로 설정하였으며, 각각의 분배율에 대하여 $93.3\%,\;92.6\%,\;92.4\%,\;91.6\%$의 $BOD_5$ 제거율 (유기물의 제거능)을 보였다. 하지만 무산소조까지의 $BOD_5$ 제거율(유기물 이용능)은 9 : 1에서 $84.8\%$로 가장 높은 것으로 나타났으며, 분배율 10 : 0, 8 : 2는 각각 $77.0\%,\;75.3\%$로서 거의 비슷한 수준이었고, 분배율 6 : 4 경우에 $61.1\%$로 가장 낮은 수치를 나타내었다. T-N 제거율은 9 : 1의 분배율로 분할하였을 때가 $67.4\%$로 가장 제거 효율이 높았으며, 분배율 10 : 0, 8 : 2 경우는 각각 $61.3\%,\;60.7\%$로 비슷한 경향을 보였으나 분배율을 6 : 4로 하였을 때는 $55.5\%$의 제거율을 나타내 분배율 9 : 1의 경우와는 약 $12\%$의 차이를 보였다. 또한 10 : 0, 9 : 1, 8 : 2의 분배율에서는 질산화가 거의 비슷한 수준으로 발생하였지만, 6 : 4로 주입하였을 경우에는 질산화의 저해가 나타나고, 방류수 중의 대부분의 질소성분이 암모니아 성분으로 방류되었다. 이 공정에서 탄소원으로 생하수를 이용하는 것이 메탄올과 같은 독성 탄소원에 비해 독성을 지니지 않고 약품비용이 들지 않는다는 측면에서 유리할 것으로 사료된다.

• 한국환경보건학회지
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• 제40권4호
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• pp.322-329
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• 2014

Objectives: The purpose of this study was to investigate the effect of BIO-CLOD on advanced wastewater treatment for enhanced removal efficiency and meeting the stringent discharge water requirements of wastewater treatment plants. Methods: Two experimental apparatuses consisting of anaerobic, anoxic and aeration tanks were operated. One included a BIO-CLOD cultivation tank. Organic and nutrient parameters and removal efficiency were analyzed by pH, BOD, CODcr, SS, T-N and T-P. Results: The average removal efficiencies of BOD, COD and SS from the apparatus with BIO-CLOD tank installation were 95.5%, 88.6% and 92.9%, respectively, and these were higher than the results from the apparatus without BIO-CLOD. The average TP removal efficiency with BIO-CLOD tank marked 56.0%, higher than the 47.3% from the apparatus without one. BIO-CLOD showed a higher performance for TN removal at 49.6%, compared to the result without BIO-CLOD of 34.3% Conclusion: By reaction with BIO-CLOD, ammonia removal was effective in the aeration tank, as was phosphorus release in the anaerobic tank. Phosphorus luxury uptake and nitrification in aeration tank proceeded smoothly. The application of BIO-CLOD can improve the decrease of odor and settleability of activated sludge in a wastewater treatment plant, as well as increase the removal efficiency of organic and nutrient materials in water.

• 한국응용과학기술학회지
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• 제31권4호
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• pp.669-678
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• 2014

The amount of waste water generated from the domestic sources is consistently increasing in proportion to economic growth, and the conventional activated sludge process is widely being used for general waste water treatment. But the ministry of environment becomes stringthent treatment standards of N and P (less than 20mg/L of N, 2mg/L of P) to prevent the eutrophication of lake water, and therefore highly advanced treatment technology is required not only in the existing treatment plants where the activated sludge process is being used, but also in newly constructed treatment plants for the treatment of N and P. This study is aimed at highly operating the engineering technology method was developed by domestic to eliminate N and P at the same time. Experiments were conducted in the treatment plant located in Yong In city. The bioreactor was started from the principal equipment for the elimination of N and P and the elimination of organic compounds. It consists of an internal recycle piping from the end of the aerobic tank to the anoxic tank and external recycle piping from the final settling basin to the denitrification tank. By experiment of 4 types separate inflow of waste water to the denitrification tank and the anaerobic tank, and changes in staying time at the anoxic tank and the aerobic tank, the elimination of organic compounds in each type and the relationship in the efficiency between the elimination of N and P were researched.

• 상하수도학회지
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• 제9권4호
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• pp.115-123
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• 1995

The purpose of this study is to investigate the characteristics and performance of nitrogen and phosphorus removal system, Daewoo Nutrients Removal(DNR) system, and to find out the operating parameter for the system. During the study, $10m^3$ pilot plant was operated for the demonstration experiment and the primary effluent was taken from K domestic sewage treatment plant. The TN in the influent had been removed to approximately 70% through the nitrfication in the oxic tank and the denitrfication in the anoxic tank and the $PO_4-P$ and TP in the influent had been removed to 85% and 83% through anaerobic reaction and oxic reaction. The BOD and SS removal rate were 85 to 95% through the system. As the results, the values of effluent BOD, SS and slouble phosphorus were lower than A/O and $A^2/O$ processes. The SPRR (specific phosphorus release rate) at the anaerobic state of DNR system was ranged from 2.2 to 2.6mg SP/g VSS/h. The nutrient removal efficieny of the DNR system in view of the characteristics of the domestic sewage was higher than the pre-established A/O and $A^2/O$ processes. Finally, we believe that the DNR system was superior to the processes deveolped recently.

• 한국도시환경학회지
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• 제18권4호
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• pp.401-408
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• 2018

하수처리 공정모델링 소프트웨어인 EQPS(Effluent Quality Prediction System, Dynamita, France)를 적용하여 A하수처리시설 생물반응조 설계의 적합성을 분석하였다. A하수처리장은 친수용수 수준의 목표수질을 준수하기 위하여 이차침전지 유출수 설계농도를 총질소와 총인, 각 10 mg/L, 1.8 mg/L로 설정하여 설계하였다. 4-Stage BNR 공정인 반응조의 체류시간은 총 9.6시간으로 전무산소조 0.5, 혐기조 1.0, 무산소조 2.9, 호기조 5.2시간이었다. 동절기 공정모델링 결과 친수용수 수준의 목표수질을 만족하기 위하여 혐기조의 체류시간을 0.2시간 늘렸고 당초 설계조건이던 외부탄소원 비상시 주입을 상시적으로 주입해야 하는 것으로 조사되었다. 모델링 결과의 왜곡을 배제하기 위하여 소프트웨어 제조사가 제시한 one step nitrification denitrification 모델의 Default 계수를 사용하였다. 공정모델링은 대체적으로 최적의 상태를 제시하기 때문에 생물반응조 여유율을 고려하면 4-Stage BNR의 체류시간은 9.8시간보다 증가시켜야 한다. 하수처리장 설계단계에서 공정 모델링의 정확한 사용은 하수처리장 건설 후 처리성능과 효율의 안정성을 담보할 수 있는 방법이므로 설계단계에서 철저한 평가가 필요하다.