• 대한환경공학회지
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• 제22권6호
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• pp.1011-1019
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• 2000

본 연구는 유입수의 농도, 수리학적 체류시간 및 F/M비와 슬러지 첨전성과의 상관관계를 새롭게 명확히 밝혀 기존에 제시된 각 처리법 즉 장기포기법, 재래식 활성슬러지법, 고율 활성슬러지법 및 수정포기법의 설계조건이 도출된 원인을 밝히고 동시에 이들 기 제시된 설계조건에 관계없이 설계가 가능함을 확인하기 위한 연구이다. 본 실험은 특히 체류시간과 미생물의 침강성을 중심으로 고찰되었는데, 이는 슬러지의 침강성이 기존 각 처리법의 운전조건을 결정하는 주인자$^{1)}$이기 때문이다. 따라서 각각의 처리법에 대해 제시된 설계범위를 벗어날 경우 슬러지는 팽화하는 것으로 알려져 있으며, 설계의 기초를 제공한 Lesperance$^{1)}$의 실험결과에서도 침강성이 확보되지 않는 부하범위가 발생하는 것으로 나타냈다. 위와 같이 일정 조건에서 슬러지가 팽화하는 원인은 Lesperance가 이전 다년간의 실패와 시도로 밝혀진 연속운전이 가능한 것으로 밝혀진 몇몇의 운전조건을 실험조건으로 채용함에 따라 각각의 체류시간에 해당하는 최적의 부하가 적용되지 않았기 때문이다. 하지만 본 실험결과 부하를 적절히 유지할 경우, F/M비 $6.3kg-BOD/kg-MLSS{\cdot}day$ 이하, HRT 0.67hr 이하의 조건에서 슬러지의 침강성이 SVI치 120 이하로 확보될 수 있음을 확인하였다. 따라서 본 연구에서는 체류시간과 그에 해당하는 최적 부하를 제시하였으며, 체류시간이 미생물의 침강성에 결정적 영향인자임을 밝히고, 아울러 본 실험결과를 근거로 이제까지 알려진 처리법에서는 적용된 바 없는 1시간 이하의 체류시간에서 고율 활성슬러지법의 적용 부하치를 수 배 능가하는 새로운 운전법 (UHR : Ultra high rate)도 가능함을 제시하였다.

• 한국환경과학회지
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• 제10권4호
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• pp.281-286
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• 2001

Wastewater from the pigment industry has high levels of organics and is known as hardly biodegradable. The objective of this study is to evaluate the applicability of aerobic fixed-bed boifilm reactor packed with ceramic support carrier for the pigment wastewater treatment. Orange 2(widely used azo pigment) adsorption experiment onto biofilm and activated sludge, and continuous treatment experiments were performed. In batch adsorption experiment, maximum adsorption quantity of biofilm was at least two times higher than that of activated sludge. In continuous experiment using aerobic fixed-bed biodilm reactor, the influent concentration of COD and Orange 2 were 75~500mg/${\ell}$(0.45~3.00kg COD/$m^3.day), 5~50mg/$\ell$(0.03~0.30kg Orange 2/$m^3$.day), respectively. At a COD loading rate 2.5kg COD/$m^3$.day and Orange 2 loading rate of 0.18kg Orange 2/$m^3$.day, removal efficiency of COD and Orange 2 were over 95%, 97%, respectively.

• 산업기술연구
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• 제16권
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• pp.61-70
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• 1996

This research aims to find granulation and organic removal of the piggery wastewater with the upflow blanket filter(UBF) reactor. UASB process had the effect of high pH on the granulation phase. But teh effect was decreased after the granule formation. The filter zone of the UBF reactor had the function of GSS and contributed to removing the organic because of its biofilm formation. The removal rates of total COD and soluble COD were 70% ~ 80% and 60 ~ 80% at an influent organic loading range of $2{\sim}17.4kgCOD/m^3{\cdot}d$, respectively. The methane production rate with the organic removal was $0.21{\sim}0.34{\ell}CH_4/gCOD_{rem}$ and the maximum methan production rate was $0.34CH_4{\ell}/gCOD_{rem}$ at the volumetric loading $5kgCOD/m^3{\cdot}d$.

• 한국농공학회지
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• 제39권3호
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• pp.64-71
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• 1997

Floating aquatic plant system using water hyacinth was applied to examine feasibility as a wastewater treatment system for the industrial complex in rural area. The wastewater from the industrial complex does not likely contain toxic pollutants because the industries which generate wastewater with toxic compounds are not allowed to move in. Pilot plant was installed at Baeksuk Nongkong Danzi in Chunahn-City, Chunchungnam - Do , and field study was performed during summer and fall of 1996. Hydraulic loading rate was 0. $0.19m^3/m^2$.day. The effluent concentration of DO was higher than influent, and it implies that 0.6m depth reactor was reaerated enough to increase DO level. The influent concentration of BOD varied significantly from less than 30 to 120mg/${\ell}$ during the study period, however, effluent concentrations were generally lower than the water quality standard and removal efficiency was up to 85%. The influent concentration of COD also showed wide variation from less than 40 to 160mg/${\ell}$ and effluent concentration was higher than water quality standard when influent concentration was over l00mg/${\ell}$. The influent concentrations of T-N and T-P were lower than water quality standard and no further treatment was required, and these compounds were also removed in the system. Although some improvement and refinement are still required, overall* the floating aquatic plant system was proved to be feasible to apply to treat wastewater from industrial complex in rural area.

• 대한환경공학회지
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• 제35권11호
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• pp.821-826
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• 2013

본 연구의 목적은 분진제거 장치에서 전극간의 적정간격을 알아보기 위한 것이다. 실험은 전극간격을 3 cm, 2 cm, 1 cm로 직렬로 놓고 유입유량을 변화시켜 수행하였다. 실험결과로부터 분진제거를 위한 적정 선속도는 6 cm/sec였고 전극표면에 부착되는 분진 총량은 전극의 간격이 가까울수록 증가하였다. 그러나 1 cm 정도로 매우 가까울 경우는 전극판에 부착된 분진은 탈착되었으며 이는 분착된 분진의 역이온화 즉 전하의 변화 때문인 것으로 사료되었다. 결과적으로 전극판에서 양전극과 음전극 간의 간격은 2 cm가 적당하고 이때의 분진부하율은 $24mg/min{\cdot}m^2$였다.

• Journal of Animal Science and Technology
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• 제45권4호
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• pp.641-648
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• 2003

본 연구에서는 돈사 폐수내의 인과 질소를 함께 결정화하여 회수하고 그 상등액을 전기분해 시키는 회분식 돈사 폐수공정에서의 오염물질 부하량과 수처리시간 변화에 따른 처리효율의 변화 및 각 오염물질 제거특성을 파악하였다. Struvite 형성을 위한 Mg원으로는 $MgCl_2$를 사용하였고 주입량은 폐수내 인 기준 1.3 Mole이었다. 총 4개의 운전(Run I, II, III, IV)에서 얻어진 평균 제거효율과 그 제거특성을 분석한 결과 인의 경우 부하량 변화에 따른 처리효율의 변화는 관찰되지 않았으며 제거의 주요 역할을 하는 반응조는 Struvite 반응조로서 적정 Mg원만 제공된다면 pH 조절제 첨가 없이 폭기만으로도 부하량에 관계없이 88% 이상의 제거가 MAP 형성을 통해 얻어지는 것으로 나타났다. 높은 암모니아성 질소 제거효율을 유지하기 위한 적정 부하량은 약 100g/$m^3$.d로서 동 부하량 이하에서는 부하량이 증가함에 따라 제거량도 증가하면서 90% 이상의 높은 효율과 일정한 제거특성을 보인 반면 그 이상에서는 불안정한 제거특성을 나타내면서 제거효율이 감소하였다. TOCs의 경우에는 부하량 변화에 따른 처리효율 변화는 관찰되지 않았으며, 그 제거효율은 수처리 시간에 의존적인 것으로 나타났다 ($r^2$ = 0.97). 색도 제거 효율은 전기분해조 용적기준 수처리시간 2일 이상에서 94%의 매우 높고 일정한 효율을 얻을 수 있었다.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제3권2호
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• pp.113-119
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• 1999

The quality of the effluent from an activated sludge aeration tank can deteriorate when the substrate removal rate decreases due to an abrupt reduction in the DO concentration, which is affected by such operating conditions as the loading rate, temperature, wastewater composition, and so on. In this research, a DO control system that includes a PI (proportional-integral) controller/Hiraoka controller was developed and applied to a pilot-scale activated sludge process, then its acceptability was estimated. The applicability of the respiration rate to DO control was also estimated. The respiration rate indicated a variety of input organic loading rates, which is the main disturbance to the DO concentration in an aeration tank. When the influent concentration incrementally decreased and increased between CODcr 1,000 mg/l and 100 mg/l, the control system with a PI controller exhibited a good llperformance-the average DO concentrations were 2.00$\pm$0.14 mg/l and 1.88$\pm$0.15 mg/l (set value was 2.0 mg/l), respectively, and the settling time was just 10 minites. When the control system was operated for 4 days, the DO concentration was 1.99$\pm$0.18 mg/l and 32.6% of the air flowrate was saved. However, the fluctuations in the respiration rates and air flowrates were severe, which could be harmful to the stability of the biomass and mechanical stability of the blower. A possible approach to solve this problem may be the simultaneous control of the loading rate and DO concentration.

• 상하수도학회지
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• 제31권5호
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• pp.415-419
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• 2017

In recent years there have been large increases in the hydraulic loading rates used to design dissolved air flotation (DAF) facilities for drinking water applications. High rate DAF processes are now available at loading rates of 20 to $40m^3/m^2{\cdot}h$. This research evaluated dissolved air flotation as a separation method for algae and organic compounds from water treatment plants. During the service period of 2016. 5. to 2017. 6., DAF pilot plants ($500m^3/day$) process has shown a constantly sound performance for the treatment of raw water, yielding a significantly low level of turbidity (DAF treated water, 0.21~1.56 NTU). As a result of analyzing the algae cell counts in the influent source, it was expressed at 100-120 cells/mL. In DAF treated water, the removal efficient of alge cell counts was found to be upto 90%. The stable turbidity and algae removal were confirmed by operating the high rate DAF process under the condition of the surface loading rate of $30m^3/m^2{\cdot}hr$.

• 상하수도학회지
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• 제14권3호
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• pp.271-280
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• 2000

This study was conducted to determine the applicable loading rate and to evaluate the possibility of using limestones as an alkalinity source for the removal of ${NO_3}^{-}-N$ remaining after denitrification/nitrification process with the down-flow sulfur packed bed reactor(SPBR). The pretreated sewage was fed to SPBR. Three SPBRs were filled with elemental sulfur particles and limestones and the volumetric ratios of sulfur to limestone were 0%, 12.5% and 25% for R-0%, R-12.5% and R-25%, respectively. The applicable loading rate was evaluated increasing flow rate with influent ${NO_3}^{-}-N$ concentration of 20 mg/L. For R-0% with external alkalinity supply, denitrification efficiency was greater than 96% up to loading rate of $354.8g\;{NO_3}^{-}-N/m^3{\cdot}day$, and corresponding EBCT was 1.4hr. For R-12.5% and R-25%, where alkalinity was supplied by the limestone filled in the reactor, denitrification efficiency was greater than 94% up to loading rate of $283.8g\;{NO_3}^{-}-N/m^3{\cdot}day$, and corresponding EBCT was 1.7hr. The slightly better performance of R-12.5 compared to R-25 suggests that the volumetric sulfur to limestone ratio of 12.5% was enough for the supply of alkalinity required for sulfur-utilizing denitrification. DO was appeared not showing inhibitory effect on sulfur-utilizing denitrification. The clogging of SPBR caused by the produced gas can effectively be eliminated by regular introduction of treated water in up-flow mode.

• 한국환경과학회지
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• 제18권3호
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• pp.325-331
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• 2009

This study was aimed to behaviour of organics and nitrogen on the upflow anaerobic reactor when a acid fermenter is added. Up flow anaerobic reactor (UAR) reaction will result which operates, COD removal efficiencies of reactor with nitrate loading rate 0.11, 0.66g/L/d were over 77%, but one with 1.0g/L/d was 73.5%. Especially, on NLR 0.11g/L/d, COD removal was 77% and nitrate removal efficiency was 93% simultaneously. The other side upflow anaerobic reactor and acid fermenter (UAR+AF) reaction will result witch operates, COD removal efficiencies of reactor with nitrate loading rate 0.11, 0.66g/L/d were over 85%, but one with 1.0g/L/d was 80%. Especially, on NLR 0.11g/L/d, COD removal was 85% and nitrate removal efficiency was 98% simultaneously. Also, without in reaction condition increase of influent nitrate concentration resulted in the linear decrease of nitrate removal efficiency and nitrate removal efficiency at influent nitrate-nitrogen 800mg/L was 50%. Alkalinity was increased theoretically by denitrification at low nitrate-N concentration, however, it was not increased theoretically at high nitrate-No 40% nitrate-N of UAR was denitrified until 70% height of reactor and 90% nitrate-N of UAR+AF was denitrified until 30% height of reactor Upflow anaerobic reactor was to occur accumulate acid, which TVA/Alkalinity is 0.3$\sim$0.47. Increase of NLR resulted increase of effluent alkalinity and TVA production