• 상하수도학회지
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• 제20권6호
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• pp.829-836
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• 2006

The reaction rate of denitrification is primarily affected by the utilization of organics that are usually limited in the anoxic period in a sequencing batch reactor. It is necessary to add an extemal carbon source for sufficient denitrification. An adaptive model of state-space based on the extended Kalman filter is applied to manipulate the dosage rate of extemal carbon automatically. Control strategies for denitrification have been studied to improve control performance through simulations. The normal control strategy of the constant set-point results in the overdosage of external carbon and deterioration of water quality. To prevent the overdosage of external carbon, improved control strategies such as the constrained control action, variable set-point, and variable set-point after dissolved oxygen depletion are required. More stable control is obtained through the application of the variable set-point after dissolved oxygen depletion. The converging value of the estimated denitrification coefficient reflects conditions in the reactor.

• Korean Membrane Journal
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• 제3권1호
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• pp.32-38
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• 2001

Using the hollow fiber membrane module in a lab-scale membrane bioreactor, the anoxic- oxic (AO) process for nitrogen removal was operated for about one year. For the influent wastewater containing 1,200-1,400 mg $1^{-1}$ of CODcr and 200-310 mg $1^{-1}$ of nitrogen, this process achieved a high quality effluent of less than 30 mgCOD $liter^{-1}$ and 50 mgN $liter^{-1}$. The removal rate of organics was above 98% at a loading rate larger than 2.5 kgCOD $m^{-3}$$d^{-1}$. When the internal recycle from the oxic to the anoxic reactor changed room 2n to 600% rout the influent flow rate, the nitrogen removal rate increased from about 70 to 90% at a loading rate of 0.4 kgT-N m-s d-1. The initial increase of transmembrane pressure (TMP) was observed after a 4-month operation while maintaining the flux and MLSS concentration at 7-9 1 $m^2$ $h^{-1}$ and 6,000-14,000 mg $1^{-1}$, respectively. The TMP could be maintained below 15 cmHg for an 8-month operation. The chemical cleaning with an acid followed by an immersion in an alkali solution gave better cleaning result with the membrane operated for 10 month rather than that only by an alkali immersion.

• 한국환경과학회지
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• 제12권1호
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• pp.55-61
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• 2003

This study was carried out to obtain the operating characteristics of SMMIAR process for biological nitrogenㆍphosphorus removal. SMMIAR was operated at HLR(Hydraulic loading rate) of 39.6, 52.8, 63.4 and 79.2 $\ell$/$m^2$/d respectively and the operating parameters such as intermittent aeration time ratio of aerobic/anoxic, DO and microorganism concentration were changed to confirm the optimum operating condition. The concentrations of the wastewater BOD, TN(Total nitrogen) and TP(Total phosphorus) were 150, 30 and 7.5mg/$\ell$ respectively. Achieving better removal efficiencies of BOD, TN and TP up to 90, 85.4 and 95.4% respectively, we must keep in operation condition of SMMIAR by 0.75 of time ratio of aerobic/anoxic and by minimum 45 minutes of oxic period simultaneously.

• 상하수도학회지
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• 제32권1호
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• pp.11-18
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• 2018

As the sequencing batch reactor process is a time-oriented system, it has advantages of the flexibility in operation for the biological nutrient removal. Because the sequencing batch reactor is operated in a batch system, respiration rate is more sensitive and obvious than in a continuous system. The variation of respiration rate in the process well represented the characteristics of biological reactions, especially nitrification. The respiration rate dropped rapidly and greatly with the completion of nitrification, and the maximum respiration rate of nitrification showed the activity of nitrifiers. This study suggested a strategy to control the aeration of the sequencing batch reactor based on respirometry. Aeration time of the optimal aerobic period required for nitrification was daily adjusted according to the dynamics of respiration rate. The aeration time was mainly correlated with influent nitrogen loadings. The anoxic period was extended through aeration control facilitating a longer endogenous denitrification reaction time. By respirometric aeration control in the sequencing batch reactor, energy saving and process performance improvement could be achieved.

• 대한환경공학회지
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• 제27권4호
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• pp.438-444
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• 2005

본 연구에서는 가변형 간벽을 설치하고 이 가변형 간벽의 열고 닫음에 따라 하나의 SBR 반응조를 시간적으로 뿐만 아니라 공간적으로도 분리시킴으로써 aerobic, anaerobic 또는 anoxic 상태의 구분을 명확히 하여 탈질 및 탈인 효율을 증대시켰다. 본 연구 결과 $COD_{Cr}$/N ratio 10($BOD_5$/N ratio 5) 정도의 실 플랜트 조건에서 T-N 및 T-P 제거효율은 90.9%와 75%를 나타내었다. 또한 잉여슬러지내 인 함유량 조사결과 기존 처리장에서 발생된 잉여슬러지의 인 함량비율을 100%라 할 때 pilot plant에서 발생된 잉여슬러지의 인 함유율은 생 슬러지의 경우 133.6%, 건조 슬러지의 경우 124.3%로서 기존 처리장의 슬러지내 인 함유율보다 $25{\sim}30%$ 정도 높은 것으로 조사되었다. 따라서 SBR반응조 내에 가변형 간벽을 설치함으로서 명확한 탈질 탈인을 위한 반응조건을 제시해 줄 수 있는 것으로 나타났다.

• 한국환경보건학회지
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• 제38권6호
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• pp.568-574
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• 2012

Objectives: The purpose of this experiment is to understand the phosphorus removal ratio effects of iron plates per unit of surface area through the iron electrolysis system, which consists of an anoxic basin, aerobic basin, and iron precipitation apparatus. Methods: Iron electrolysis, which uses an iron precipitation reactor in anoxic and oxic basins, consisted of iron plates with total areas of 400 $cm^2$, 300 $cm^2$ and 200 $cm^2$ respectively. The FNR process was operated with a hydraulic retention time and a sludge retention time of 12 hours and three days, respectively. Wastewater used in the experiments was prepared by dissolving $KH_2PO_4$ in influent water. Results: The iron plates 400 $cm^2$ (16.6 $mA/cm^2$), 300 $cm^2$ (13.3 $mA/cm^2$) and 200 $cm^2$ (7.3 $mA/cm^2$) in surface area in the phosphorus reactor had respective phosphorus of 2.4 mg/l, 2.7 mg/l and 3.2 mg/l in the effluent and phosphorus removal respective efficiencies of 90.3%, 89.1% and 87.1%. The effluent in the reactor, where the iron plate was not used, had relatively very low phosphorus removal efficiency showing phosphorus concentration of 15.3 mg/l and a phosphorus removal efficiency about 38.3%. Phosphorus removal per ferrous was 0.472 mgP/mgFe in the iron electrolysis system where the surface area of iron was low. Phosphorus pollution load per active surface area and the phosphorus removal efficiency had an interrelation of RE = -0.27LS + 89.0 (r = 0.85). Conclusion: With larger iron plate surface area, the elution of iron concentration and phosphorus removal efficiency was higher. The removal efficiency of phosphorus has decreased by increasing the initial phosphate concentration in the iron electrodes. This shows a tendency of decreasing phosphorus removal efficiency because of decreasing of iron deposition as the phosphorus pollution load per active surface area increases.

• 한국축산시설환경학회지
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• 제14권2호
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• pp.113-118
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• 2008

Sequencing batch operation consists of fill, react, settle and decant phases in the same reactor. Operation consists of anaerobic, anoxic and oxic (aerobic) phases when nutrient removal from the wastewater is desired. Since the same reactor is used for biological oxidation (or mixing) and sedimentation in aerobic and anaerobic SBR operations, capital and operating costs are lower than conventional activated sludge process and conventional anaerobic digestion process, respectively. Therefore, Aerobic SBR and Anaerobic SBR operations may be more advantageous far treatment of small volume animal wastewater in rural areas.

• 한국환경보건학회지
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• 제26권3호
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• pp.98-102
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• 2000

The aim of this study was to evaluate on the removal effect of total nitrogen in municipal wastewater by decreasing hydraulic retention time(HRT) from 6 hour to 4 hour on CNR process. CNR-A(Cilia Nutrient Removal) is the process combining A2/O process with cilium media of H2L corporation. The removal efficiencies for T-N were 63.1% in A-1 reactor, and 73.5% in A-2 reactor and 77.0% in A-3 reactor. The specific nitrification(g-NH3-N/g-MLVSS.d) of Oxic in CNR-A process was 0.07-0.32. The specific denitrification in Anoxic and the specific nitrification inOxic was higher in HRT 4 hour because of optimum F/M ratio.

• 상하수도학회지
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• 제8권1호
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• pp.18-26
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• 1994

This research investigated efficient operation mode for the successful performance of SBR(sequencing batch reactor) treating fish processing wastewater, and the effect of sodium chloride (NaCl) on treatment efficiency. 2-hour-annerobic, 6-hour-aerobic and 3-hour-anoxic operation during reaction period was found an effective operating method for organic and nitrogen removal from fish processing wastewater in SBR system. The average removal efficiencies of COD, BOD, and total nitrogen in SBR operated continuousely were 91%, 95%, and 67.1%, respectively. The estimated values of biomass yield coefficient(Y), microbial decay coefficient($K_d$), and bioreaction rate constant(K) were $0.35gMLSS/gCOD_{removed}$, $0.015day^{-1}$, and $0.209hr^{-1}$, respectively. As NaCl concentration increased from 5 to 30g/L, sludge settleability was cnhanced but organic removal in the reactor was decreased. NaCl of influent had considerable relationship with COD removal, whereas it did not significant affect nitrogen removal.

• 대한환경공학회지
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• 제35권5호
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• pp.301-306
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• 2013

본 연구는 퍼클로레이트($ClO_4{^-}$)와 질산염($NO_3{^-}$)의 직접적인 처리방법으로 무산소/호기생물막반응조와 MF막에 의한 연속처리의 적용 가능성을 조사하였다. 생물막 처리공정은 첫 번째 단계로 퍼클로레이트와 질산염의 제거를 위해 무산소생물막반응조를 이용하였고 두 번째 단계로 이화적 퍼클로레이트와 질산염 환원을 위해 사용된 잔류탄소원의 제거를 위해 호기생물막반응조가 도입되었다. 그리고 마지막 단계로 탁도제거를 위해 중공사형 MF막을 적용하였다. 본 연구에서 102 ${\mu}g/L$ $ClO_4{^-}$와 61.8 mg/L $NO_3{^-}$ (14 mg/L $NO_3$-N)가 유입수로 주입되어 퍼클로레이트는 IC 검출농도 이하(5 ${\mu}g/L$ $ClO_4{^-}$)로 제거되었으며 질산염은 최종 처리수의 농도가 4.4 mg/L $NO_3{^-}$ (1 mg/L $NO_3$-N)로 제거되었다. 탄소원으로 사용된 과잉의 179 mg/L 유입 $CH_3COO^-$는 무산소생물막반응조의 유출수에서 117 mg/L, 호기생물막반응조의 유출수에서 11 mg/L로 감소하였다. 3 NTU의 유입 탁도는 무산소/호기생물막반응조의 유출수에서 1.5와 0.3 NTU였으며 최종 MF막의 유출수에서 0.2 NTU였다. 이 결과는 지표수와 지하수에 포함된 저농도 퍼클로레이트와 질산염 오염의 직접적인 처리방법으로 무산소/호기생물막반응조와 MF막의 연속처리가 적용될 수 있음을 의미하는 것으로 사료된다.