• 상하수도학회지
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• 제20권2호
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• pp.289-294
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• 2006

A pilot scale non-woven fabric filter separation activated sludge system was investigated for practical application on domestic wastewater reclamation and reuse. The system was operated in A/O (Anaerobic/Oxic) process with submerged filter module in the aerobic compartment. In the test of two types of filter materials ($70g/m^2$ and $35g/m^2$), the initial flux (0.42m/d) could be maintained for about three months by regular air backwashing of $70g/m^2$ filter at 0.3m water head. The removal efficiency of organic matter by the system was BOD 93.3%, CODcr 96.3%, SS 96.7%. The effluent quality was 7.8mg/L, 12mg/L and 5mg/L for BOD, CODcr and SS, respectively. The water quality was enough to meet a standard for domestic reuse without human contact. T-N removal efficiency was 49.9% at internal recycle rate 2Q and C/N ratio 3.3. The removal efficiency of T-P was 50% with average effluent concentration, 2.6mg/L.

• 한국물환경학회지
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• 제18권2호
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• pp.141-150
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• 2002

Two-stage membrane bioreactor using submerged hollow fiber membrane was applied in laboratory scale to treat nitrogen and phosphorus of domestic wastewater. Alum as the flocculant and adsorbent was added into the anaerobic basin of two-stage membrane bioreactor and mixed liquid of aerabic basin was recycled to the anaerobic basin for the purpose of nitrogen removal. Experiment was carried out to find removal efficient of phosphorous and nitrogen components in the mixed liquid, and the stability of the permeate flux and pressure of two-stage membrane bioreactor. In case of alum was added as the flocculant and adsorbent into the anaerobic basin, soluble phosphorus removal efficient was relatively higher and total permeate resistance(Rtot) was more increased out nitrogen removal efficient was lower as the result of lack of alkalinity and insufficient nitrification process than the case of alum was not added.

• 한국수소및신에너지학회논문집
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• 제27권1호
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• pp.49-62
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• 2016

In this study, a solid oxide fuel cell (SOFC) system model including balance of plant (BOP) for building electric power generation is developed to study the effect of operating conditions on the system efficiency and power output. SOFC system modeled in this study consists of three heat-exchangers, an external reformer, burner, and two blowers. A detailed computational cell model including internal reforming reaction is developed for a planer SOFC stack which is operated at intermediate temperature (IT). The BOP models including an external reformer, heat-exchangers, a burner, blowers, pipes are developed to predict the gas temperature, pressure drops and flow rate at every component in the system. The SOFC stack model and BOP models are integrate to estimate the effect of operating parameters on the performance of the system. In this study, the design of experiment (DOE) is used to compare the effects of fuel flow rate, air flow rate, air temperature, current density, and recycle ratio of anode off gas on the system efficiency and power output.

• 한국농공학회논문집
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• 제49권2호
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• pp.75-86
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• 2007

This process which has a connection of biofilter and sulfur-limestone has been developed to treat organic substances including BOD, COD and SS etc. and to treat sulfur-limestone is for denitrification.. The whole process consists of chemical reaction tank, sedimentation tank, trickling filter, denitrification tank The trickling filter is equipped with a reactor filled with absorptive filter, and the sulfur denitrification tank is filled with sulfur-limestone mixed media. After setting up practical facilities whose capacity is 60 tons a day, we have observed the removal efficiencies of pollutants through 60 experiments during Summer and Winter seasons. The average concentration of polluted water was BOD for 3.6 mg/L, $COD_{Mn}$ for 11.3 mg/L, SS for 2.8 mg/L, T-N for 8.6 mg/L, and T-P for 0.8 mg/L, and the rate of treatment efficiencies 96.5%, 84.7%, 96.5%, 79.2%, and 80.8%, respectively was found through the experiments. The average treatment efficiency for BOD and $COD_{Mn}$ was 85.0% and 55.7%, respectively and the average removal efficiency for NH4+-N was 84.9% in the trickling filter. The removal efficiency in the denitrification tank is as follows; The removal rate of $NO_3^--N$ was as high as 93.2% within the compass of pH 6.3 to 7.3 through $16.8{\sim}37.0mg/L$ flown into $NO_3^--N$ and $0.1{\sim}8.3mg/L$ outflown. It had observed that this process has implemented highly efficient and advanced treatment without external carbon sources and internal recycle during its process. In conclusion, this process is suitable for a sewerage in a small village due to the merits of low power consumption and easy maintenance.

• 한국물환경학회지
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• 제20권5호
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• pp.457-465
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• 2004

The objective of this study is to evaluate the possibility to apply the Moving Bed Biofilm Reactor(MBBR) in the activated sludge treatment process with existing aerobic HRT. Optimal operation conditions were assumed according to the analysis of organic matter and nutrients removal efficiencies depending on loading variations. The process was operated under different conditions: RUN I(HRT=7.14hr, $I{\cdot}R=100%$), RUN II(HRT=6.22hr, $I{\cdot}R=100%$), RUN III(HRT=6.22 hr, $I{\cdot}R=150%$), RUN IV(HRT=6.22hr, $I{\cdot}R=200%$), the TBOD removal efficien cies are 88%, 88.5%, 94.6%, 97.6%, respectively. Overall TSS removal efficiency is 90%, and it is increasing in RUN IV. In the case of Nitrogen, the highest removal efficiency of 90% was observed in RUN III and RUN IV, Nitrification and Denitrification rates are 0.013-0.016kg $NH_3-N/kg$ Mv-d and 0.009-0.019kg $NO_3/kg$ Mv-d, respectively. Phosphorus removal efficiencies are 89.6% in RUN I, 91.5% in RUN II, 84.3% in RUN III, and 76.4% in RUN IV. The process under shorter SRT yields better performance in terms of phosphorus removal. It was noticed that to achieve the effluent phosphorus concentration ofless than 1mg/L and removal efficiency higher than 80%, SRT should not be longer than 10 days. Experimental result shows that HRT of 6.22 hours is suitable for this treatment process, and, as a result, the aerobic reactor including moving media and DO depletion tank have a sufficient effect to the process performance.

• 접착 및 계면
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• 제21권3호
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• pp.81-85
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• 2020

Shaving dust는 천연 피혁 제조 공정 중 두께 조절을 위해 발생하는 피혁 폐기물인 콜라겐 섬유로 크롬을 함유하고 있어 매립 시 환경오염 문제를 야기시킨다. 현재 유럽을 중심으로 다양한 국가에서 피혁 폐기물인 Shaving dust를 활용한 다양한 연구가 진행되고 있으며, 그 중 재생피혁(Bonded leather)은 천연 피혁 대체가능한 소재로 주목받고 있다. 재생 피혁은 바인더로 라텍스를 사용하여 다른 합성 피혁에 비해 내부 조직이 치밀하여 중량감이 높고 통기성이 저하되는 단점이 있어 열팽창성 Microsphere를 도입하여 내부 조직을 완화시켜 통기성 및 경량성 등 기능성을 개선하고자 하였다. 본 연구에서는 Shaving dust를 활용한 경량 재생피혁 제조에 관한 연구로, 열팽창성 Microsphere를 적용한 후 콜라겐 섬유의 내열성을 감안하여 100~120℃에서 발포시켜 그 경향성을 분석한 결과 120℃에서 8분간 처리하였을 때 가장 우수한 발포율을 나타내었고, 재생 피혁 단면의 SEM 분석을 통해 발포에 따른 내부 조직의 변화를 관찰하였다.

• 대한환경공학회지
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• 제33권7호
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• pp.485-491
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• 2011

본 연구는 2개의 간헐혐기조, 막분리호기조 및 슬러지 가용화로 구성된 유로변경형 membrane bioreactor의 운영을 통하여 도시 하수의 영양염류 제거 특성을 규명하였다. 수리학적 체류시간(HRT)과 운영 여과 플럭스의 평균값은 각각 6.5 시간과 $20.4L/m^2{\cdot}hr$ (LMH)이었으며, 공정을 운전한 결과, $COD_{Cr}$, SS, TN 및 TP의 평균 제거율은 각각 94.0%, 99.3%, 99.9%, 69.9%와 66.9%이었다. 슬러지 생산계수, SDNR, SNR, SPPR 및 SPUR은 각각 0.34 kg VSS/kg BOD d, $0.067mg\;NO_3-N/mg\;VSS{\cdot}d$, $0.028mg\;NH_4-N/mg\;VSS{\cdot}d$, 16.0 mg P/g VSS d 및 2.1 mg P/g VSS d였다. 또한, 생산된 슬러지의 평균 질소 및 인 함량은 각각 8.9%와 3.5%였다.

• 한국산학기술학회논문지
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• 제8권4호
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• pp.861-866
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• 2007

본 연구는 하 폐수 중의 유기물뿐만 아니라 질소, 인을 생물학적으로 제거하기 위하여 Bacillus sp. 미생물을 사용하였다. Bacillus sp. 미생물이 생존하기에 알맞지 않은 상황에서는 포자를 형성하고, 증식과 포자화를 반복하면서 우점화되는 특성을 발현시키기 위해 점감포기를 실시하였다. 반응기 용존산소 농도는 포기조 1단; $1.2{\sim}l.5mg/L$, 포기조 2단; $0.3{\sim}$0.5mg/L, 포기조 3단 ; 0.2mg/L이하로 유지하였다. 또한 공정내 미생물의 유실을 방지하고 미생물이 고농도 상태로 유지 가능한 부착성장의 한 공법인 RBC에 끈상 나선형 미생물 접촉재를 설치한 반응기를 이용하였다. 식종한 Bacillus sp.가 적응하는 기간에서의 유입유량은 173 L/d, 내부반송율 200%, 슬러지반송율 100%로 운전을 하였으며, 방류수질을 기준으로 단계적으로 유입유량을 증가시켰다. 정상상태에서 유입유량은 346 L/d이고, 내부반송율과 슬러지 반송율은 각각 50%로 결정하여 실험을 수행하였고, 원수는 Glucose 1,800 mg/L. $NH_4Cl\;500mg/L,\;KH_2PO_4\;5mg/L$를 혼합한 인공폐수를 제조하여 공정에 주입하였고, 그 결과 각각 미생물이 폐수에 적응하는 단계인 Period 1에서는 각 수질 분석 항목의 농도가 점차적으로 감소하는 경향을 보였으며. 정상상태라고 판단한 Period 2에서는 최종적으로 유입수에 대한 유출수의 제거율은 각각 TCODCr 94%. BOD 87%, T-N 85%, T-P 89%의 결과를 나타내었다.