• 한국축산시설환경학회지
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• 제8권3호
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• pp.153-158
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• 2002

활성오니처리를 한 양돈폐수 방류수의 잔여오염물질을 정화하고 색도 구성물질을 분해하고자 4개의 오존처리조와 폭기조, 침전조 등으로 구성된 처리소 총 처리조용량이 594.5l이고 1일 200l씩 처리가 가능한 20g/hr의 오존발생기가 부착된 오존이용 탈색 시스템을 개발하였으며 그 시험 결과는 다음과 같다. 1. 오존처리시 온도는 반응열에 의하여 처리전 31.$0^{\circ}C$에서 처리중에는 41.9$^{\circ}C$까지 증가하였으며 pH도 처리 과정 중에 계속적으로 증가했다. 2. 산화환원전위차는 처리전에 148㎷였으나 처리중에 증가하여 330㎷까지 증가하였으며 처리가 완료된 후 방류조에서는 다시 감소하였다. 3. BOD의 경우 처리전 11mg/l였으나 처리후에 1mg/l로 낮아졌으며 CO $D_{MN}$ 의 경우에도 83mg/l에서 1.0mg/l으로 낮아졌다. 4. 활성오니처리 방류수의 색도는 442도였으나 오존처리후에는 색도가 6도로 98.6%의 높은 색도제거효율을 보였다.

• 한국수소및신에너지학회논문집
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• 제15권3호
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• pp.187-193
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• 2004

In this study, Anaerobic sewage sludge in a batch reactor operation at $35^\circ{C}$ was used as the seed to investigate the effect of pretreatments of waste activated sludge and to evaluate its hydrogen production potential by anaerobic fermentation. Various pretreatments including physical, chemical and biological means were conducted to utilize for substrate. As a result, SCODcr of alkali and mechanical treatment was 15 and 12 times enhanced, compared with a supernatant of activated sludge. And SCODcr was 2 time increase after re-treatment with biological hydrolysis. Those were shown that sequential hybridized treatment of sludge by chemical & biological methods to conform hydrogen production potential in bath experiments. When buffer solution was added to the activated sludge, hydrogen production potential increased as compare with no addition. Combination of alkali and mechanical treatment was higher in hydrogen production potential than other treatments.

• 한국환경보건학회지
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• 제27권3호
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• pp.43-48
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• 2001

Terephthalic acid and ethylene glycol resulting form the weight-reduction process of polyester make trouble in the operation of activated sludge process. Also, polyester weight loss wastewater shows high pH, high organic strength and wide variation of organic loading. Therefore, this study was conducted in order to improve treatment efficiency by activated sludge process with Pseudomonas sp degrading components of polyester weight loss wastewater. The CO $D_{Mn}$ and BO $S_{5}$ of the waste wastewater were 560~3,000 mg/$\ell$ and 8000~3,000 mg/$\ell$, respectively. pH was 11.8~12.3. COD removal efficiency by activated sludge-coagulation process with Pseudomonas sp was 94.1~95.8% for 35 hr of hydraulic retention time. Total organic carbon removal efficiency was 97.1%. Ethylene glycol and terephthalic acid in the wastewater were completely degraded during 32 hr of hydraulic retention time.e.

• 한국환경보건학회지
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• 제18권2호
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• pp.57-61
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• 1992

This study was made for enhanced removal of N and P by intermittented aeration Activated Sludge Process. Experiment were conducted to find the effects of aeration interval and nutrient removal efficiency. When applied aeration interval were 30~60 min, 2~4 h, 4~8 h, organic matter was not affected while phosphorous removal was aeration interval 30~60 min. Also, when applied mixing intensity were 15, 30, 45 and 60 rpm, organic matter was not affected while removal was maximum at 15 rpm. Total nitrogen and phosphorous removal were in the range of 76 and 85%. Density and MLSS of Sludge were in the range of 2.3~2.6 and 7198~7810 mg/l. Release of phosphorous from activated sludge under unaerobic condition was increased as pass time.

• 한국환경과학회지
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• 제13권6호
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• pp.571-579
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• 2004

There is a need to improve the efficiency of the existing sanitary treatment facilities, because the effluent standard becomes more stricter and septic sludge increased. Thus, operating processes of sanitary treatment system in M city changed with installation of additional facilities. Process modifications were as follows: Dilution water was added to the next process after primary aeration tank. Some secondary sedimentation sludge was recycled to primary aerator so that most of the organics were stabilized in primary aeration tank under automatic control of dissolved oxygen. The line of effluent from dewatering process flowing to the activated sludge tank was changed to the primary aerator. The primary sedimentation sludge line was linked to a thickener. Polymer was added to the activated sludge tank. The effluent of primary aerator and aerobic digester was recycled from the 5th to the 1st sector. As consequencies of above process modifications, the improvement of removal efficiency was achieved as BOD 54%, COD 42%, SS 61%, T-N 39%, and T-P 12%, respectively.

• Journal of Microbiology and Biotechnology
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• 제13권1호
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• pp.15-21
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• 2003

Two microbial communities of activated sludge in the same municipal wastewater, but treated with different systems, were studied and compared using molecular microbiological approaches. The bacterial 16S rDNA sequences from 124 clones were analyzed, however, the majority of them were not closely related to any known species, and found to belong to 8 different phylogenetic groups and 3 different unidentified groups. The relative frequencies of each group were similar between the two microbial communities. Fingerprinting using terminal restriction fragment length polymorphism (T-RFLP) showed that the putative Nitrospira-related populations were more diverse and quantitatively higher in the KNR process system than in the other system using a conventional activated sludge process. The relationship between the bacterial community composition and the higher removal efficiency of nitrogen and phosphorus in the KNR process is discussed.

• Environmental Engineering Research
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• 제25권3호
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• pp.400-408
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• 2020

Hydrodynamic study of Activated Sludge Process (ASP) is important to optimize the reactor performance and detect anomalies in the system. Residence time distribution (RTD) study has been performed using LiCl as tracer on a pilot scale aeration tank (AT) and ASP, treating the pulp and paper mill effluent. The hydraulic performance and treatment efficiency of the AT and ASP at different operating parameters like residence time, recycle rate was investigated. Flow anomalies were identified and based on the experimental data empirical models was suggested to interpret the hydrodynamics of the reactors using compartment modelling technique. The analysis of the RTD curves and the compartment models indicated increase in back-mixing ratio as the mean hydraulic retention time (MHRT) of the tank was increased. Bypassing stream was observed at lower MHRT. The fraction of dead zone in the tank increased by approximate 20-25% with increase in recycle rate. The fraction of the stagnant zone was found well below 5% for all performed experiments, which was under experimental error. The substrate removal of 91% for Chemical oxygen demand and 96% for Biochemical oxygen demand were observed for the ASP working at a hydraulic mean residence time 39 h MRT with a 20% recycling of activated sludge.

• 대한환경공학회지
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• 제29권3호
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• pp.304-310
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• 2007

본 연구는 초단파조사 처리된 잉여슬러지를 하수와 함께 활성슬러지공법으로 처리할 때 하수처리효율과 잉여슬러지 발생량에 미치는 영향을 파악하기 위하여 실시되었다. 온도가 $20^{\circ}C$이고 MLSS농도가 약 2,000 mg/L인 250 mL의 잉여슬러지를 발진주파수가 2,450 MHz이고 정격고주파출력이 700 W인 전자렌지(microwave oven)로 초단파조사 처리한 결과 조사시간이 1분 증가함에 따라 수온이 약 $20^{\circ}C$씩 증가하였으며, 슬러지의 SCOD, TKN 및 T-P 농도는 모두 $40\sim130$ sec의 조사시간에서 가장 많이 증가하였다. 그리고 혼합액 미생물의 산소섭취율을 측정한 결과 130 sec 이상의 조사시간($65^{\circ}C$ 이상)에서는 혼합액의 미생물이 거의 사멸하는 것으로 나타났다. 잉여슬러지를 초단파조사 처리한 다음 하수와 혼합시켜 활성슬러지공법으로 처리하였을 때 유입수 및 처리수의 pH 및 알칼리도에는 거의 영향이 없었으나, 유입수의 SS, COD, T-N 및 T-P 농도는 증가하였으며, 처리수의 SS, BOD 및 T-P 농도는 거의 영향을 받지 않았으나 COD 및 TKN 농도는 증가하였다. 그리고 초단파 조사비가 1 g SS/g SS-day 증가할수록 미생물성장계수 값은 0.91 g SS/g COD removed의 율로 감소하였다.

• 한국막학회:학술대회논문집
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• 한국막학회 1998년도 추계 총회 및 학술발표회
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• pp.150-152
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• 1998

Now the lack of water is serious problem all over the world because of the growth of population and expansion of industrial activities. So wastewater recycle and reuse is essential in many countries. One of the most popular wastewater treatment processes is conventional activated sludge system. In spite of significant degree of treatment rate the biological process has some operational difficulties and capital disadvantages. In conventional activated sludge process, sludge settling condition is getting worse in case of sludge bulking, it is common that overall process fails due to wash-out of biomass causing low concentration of MLSS in the aeration tank. Because of the absence of claifier the membrane bioreactor(MBR) process is less affected by such problems.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.209-212
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• 1990

The activated sludge process is a commonly used method for treating sewage and waste waters. The process is characterized by a lack of measurement instrumentations and control goals that are neither well defined nor well understood. In the present study the concept of fuzzy control is employed for such process in which a design method for fuzzy controller based on a multivariable fuzzy reasoning algorithms is investigated and then simulation results are presented.