• 한국물환경학회지
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• 제26권1호
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• pp.140-147
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• 2010

In existing design method for aeration tank water temperature was considered as governing variable for applying safety factor. This study tried a few new approach of aeration tank design using SOUR at various temperature conditions. Specific substrate utilization rate (U) and specific oxygen uptake rate (SOUR) both were analyzed at various temperature and SRT. The laboratory scale reactor was operated on various temperature ($10^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$) and SRT (5day, 10day, 20day, 30day). In this study, SOUR tended to increase with the temperature increased. On the other hand, SOUR tended to decrease when SRT increased from 5 days to 30 days. Empirical equations were obtained SOUR=a/SRT+b and $SOUR=(a/m){\cdot}U+(b-a(n/m))$ from the relationship between SRT, U and SOUR. Empirical equations shows the possibility as a new design method for the aeration basin.

• KSBB Journal
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• 제28권3호
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• pp.157-164
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• 2013

Depending on season, mixed wastewater can show great deviations in terms of the influent ratios of tannery and seafood-wastewater. Increases in the ratio of tannery wastewater in influent water also result in increases in the concentration of chromium, which decreases the ratio of BOD/T-N so that the removal efficiency of organic and nitrogen pollutants in biological wastewater treatment deteriorates. No substantial differences occur in the ratios of Eubacteria/total bacteria as the ratio between tannery wastewater and seafood wastewater changes in the influent water. In contrast, the cell numbers and activities of Eubacteria and total bacteria significantly decline with increasing ratios of tannery wastewater in the influent water. Stable removal of organic and nitrogen pollutants by biological wastewater treatments leads to dominance of Proteobacteria groups in all biological treatment basins. In aeration and oxic basins, ${\gamma}$-Proteobacteria account for approximately 21% of the Eubacteria groups, at $1.9{\times}10^9{\sim}2.0{\times}10^9$ cells/mL, while in an anoxic basin, ${\beta}$-Proteobacteria account for approximately 19% of the Eubacteria groups, at $1.3{\times}10^9$ cells/mL. However, a substantial decline in dominance of approximately 11% occurs for ${\gamma}$-Proteobacteria in aeration and oxic basins and about 1% for ${\beta}$-Proteobacteria in an anoxic basin. Mixed wastewater that undergoes extensive property changes of the influent water shows an efficiency of biological treatment that is greatly influenced by the ratio of dominant Proteobacteria groups.

• 대한환경공학회지
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• 제22권1호
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• pp.91-101
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• 2000

휘발성 유기화합물 (VOCs)은 하수처리장, 위생 매립지, 자동차, 산업활동 등에서 주로 발생 되는데, 인간에게 독성 또는 발암성 물질로 작용하며 광화학 반응에 의해 오존 생성의 주역할을 하고 있다. 하수처리장의 VOCs의 배출량을 조사하기 위해, 미국 LA시의 Hyperion 하수처리장을 선택하여 배출되는 VOCs 의 종류와 Flux를 계산하여 측정값과 비교하였다. 조사결과, 하수와 관련이 있고 자동차 연소 혹은 해양의 공기와는 관련이 없는 화합물 (DCM, TCM, PCE, LIM, DCB, UND) 의 포기조 상공 바로 뒤의 풍하위치에서 이들 화합물의 농도는 풍상보다 최소 열 배 이상 높았다. 상대적으로 생분해가 늦거나 생분해가 되지 않는 화합물인 DCE, DCM, TCA, DCA, TCM, PCE, DCB의 측정 Flux는 포기조에 공급된 포기량, 헨리의 계수, 포기조내의 액상농도를 기초로 하여 계산된 Flux와 잘 일치하였다. PCE, DCE, TCA와 같은 화합물의 Flux비(측정/계산)는 거의 1이었다.

• 한국환경과학회지
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• 제14권9호
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• pp.811-815
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• 2005

The activated sludge from the aeration basin of the Su-yeong municipal wastewater treatment plant which has operated by a standard activated sludge process in Busan, Korea was investigated during April 2004 and January 2005 with several bio-indicators. The number of bacteria and fungi per gram of dry weight of MLSS were estimated to be $3.1\times10^6\sim1.5\times10^8\;and\;l.1\times10^3\sim1.1\times10^5$ colony forming units, respectively, by the plate agar method. By cultivation-independent methods, such as 4',6-diamidino-2-phenylindole stain and fluorescence in situ hybridization, the ratio of eubacteria to the entire biomass was evaluated by more than $80\%$ (v/v). The ratio of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria to the total eubacteria was detennined to be $7.0\sim9.8\%\;and\;3.3\sim6.2\%$ without heavy variation in spite of a period of relatively low temperature in the basin. It would be expected that the nitrification would occur or at least co-exist throughout the year in the sludge of many municipal WWTP with influents that contain the sufficient nitrogen sources although the WWTP does not have any specialized processes for the removal of nitrogen.

• 환경위생공학
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• 제13권1호
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• pp.26-31
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• 1998

Removal of nitrogen and phosphate in wastewater is concerned to important for the prevention of eutrophication in receiving water and lake. Conventional activated sludge system designed for organics removal can be retrofitted only by modification of aeration basin to maintain anaerobic and aerobic state. Biological nutrient removal processes(BNR) such as Bardenpho, A$^{2}$/O, UCT, VIP were generally used for the treatment of wastewater. However these BNR processes used in large scale WWTP were not suitable in small scale WWTP(i.e., package type WWTP) due to relatively large fluctuation of flow rate and concentration of pollutants. The purpose of this research was to develop the compact, effective and economical package type WWTP for the removals of carbon and nitrogen in small scale wastewater. Intermittently aerated activated sludge system (IADFAS) were investigated for removal of nitrogen in both domestic wastewater, Bardenpho process was also evaluated. Nitrogen removal of IAAS, IADFAS, Bardenpho were 75, 77 and 67%, respectively.

• Journal of Microbiology
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• 제41권2호
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• pp.83-88
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• 2003

The taxonomic position of actinomycete strain SCNU5$\^$T/, isolated from extensive foam in the aeration basin of an activated sludge process, was clarified by phenotypic, chemotaxonomic and phylogenetic analyses. The strain possesses wall chemotype IV, MK-9(H$\^$0/), as the major menaquinone, and contains saturated, monounsaturated and 10-methyl branched fatty acids. The G+C content of its DNA is 68.1 mol%. Phenotypic data and DNA relatedness to known species indicate that the strain SCNU5$\^$T/ represents a new species within the genus Tsukamurella, for which we propose the name Tsukamurella sunchonensis SP. NOV. The type Strain Of T. sunchonensis is SCNU5$\^$T/ (=KCTC 9827$\^$T/).

• Journal of Microbiology
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• 제37권2호
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• pp.66-72
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• 1999

Mycolic acid-containing actinomycetes associated with extensive foaming in the aeration basin of the activated sludge process were isolated and analyzed by phenotypical, chemotaxonomical and phylogenetic methods. Whole cell sugar patterns of two isolates were pattern A. The nearly complete sequences of the 16S rRNA genes (rDNAs) of the isolates were determined and compared by using several tree-making algorithms. With polyphasic methods, strain SCNU1 was identified as Gordona sputi, and strain SCNU5 assigned to the genus Tsukamurella. The presence of opportunistic pathogens of chronic lung infections within foams can cause public health problems and render waste-treatment processes inefficient.

• Ocean and Polar Research
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• 제26권1호
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• pp.102-111
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• 2004

Recirculating aquaculture system (RAS) consists of different treatment compartments that maintain water quality within the ranges commonly recommended for fish cultures. However, common RASs still exert considerable environmental impact since concentrations of organic matter and nutrients in their effluents are high. Compared with the traditional RAS, the model RAS developed here use a sedimentation basin for digestion purposes and then use the released volatile organic matter to stimulate a denitrification process. Different treatment compartments for solids, total ammonia nitrogen, and nitrate removal have been reviewed. This paper provides the basic information on designing different treatment compartments as well as the engineering criteria in closed seawater RAS, consisting of circular tanks for fish cultures; dual drain systems, sedimentation basins and foam fractionators for removal of solids; nitrification biofilters for TAN removal; denitrification biofilters for nitrate removal; and aerators for aeration. The main purpose is to outline a common procedure in designing of closed RAS for marine fish culture with an emphasis on easy management and low expense, as well as reduction of the environmental impact.

• 대한환경공학회지
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• 제38권9호
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• pp.469-475
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• 2016

본 연구는 실제 운영되는 수산물 가공 산업폐수의 immersed MBR (iMBR)공정을 이용한 폐수처리시설 운영 결과에 대한 실증적 고찰을 수행한 것이다. 수산물 가공 산업의 특성상 일별, 월별 유량 변동이 심하여 유량조정조의 설계 및 운전방법이 중요하며, 유량조정조 교반시 포기식 교반을 적용하면 산발효 방지를 통하여 후속 응집/부상 공정의 약품비 절감이 가능하다. 동 현장은 유량조정조, 가압부상조, iMBR을 거쳐 방류하며, 이때 가압부상조를 거쳐 iMBR로 유입되는 BOD, $COD_{Mn}$, SS, T-N, T-P의 농도는 2,291 mg/L, 530 mg/L, 38 mg/L, 256.8 mg/L, 13.5 mg/L으로 나타났다. 수산물 가공 폐수와 같이 고농도의 염이 함유된 폐수의 생물학적 처리는 슬러지의 침강성과 관계없는 침지식 중공사막을 이용한 iMBR 공법을 적용하는것이 바람직한 것으로 나타났다. iMBR 공정의 주요 에너지 소모 요인인 공기세정에 대한 운영 값의 검토 결과 SADm값이 $0.31m^3/hr{\cdot}m^2$ membrane area이었으며, SADp값은 $26.5m^3/hr{\cdot}m^3$ permeate으로 상용화된 평막 대비 월등히 에너지 효율이 우수한 것으로 나타났다. 무산소, 혐기, 호기 탈기조로 구성된 침지식 중공사막이 결합된 iMBR 공정에서 막오염 지표인 Normalized TMP와 온도, MLSS 등을 비교 분석한 결과 F/M비가 0.08~0.10 gBOD/gMLSS에서 임계 F/M 값을 나타냈다. 생물반응조에서의 BOD, $COD_{Mn}$, SS, T-N, T-P의 처리수질은 각각 1.8 mg/L, 11.0 mg/L, 1.1 mg/L, 11.0 mg/L, 0.24 mg/L으로 운전되었으며, 제거율은 99.9%, 97.9%, 96.3%, 95.7%, 97.8%으로 나타났다.

• 청정기술
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• 제7권1호
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• pp.35-42
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• 2001

본 연구에서는 zeolite를 활성슬러지 공정에 주입할 경우 zeolite가 biofloc에 미치는 영향에 대해 알아보기 위해 수행되었다. 두 반응기를 동일 조건으로 운전하였으며 하나는 표준 활성슬러지 공정 (CU)으로, 다른 하나는 zeolite를 폭기조내 4,000 mg/l로 유지 (ZU)하며 비교하였다. 슬러지 플럭 입경을 측정한 결과, 두 반응기 모두 SRT (Solid Retention Time)가 증가함에 따라 플럭 크기도 비례하여 증가하였으나 ZU가 모든 조건에서 CU보다 작은 평균 입경을 나타내었다. 한편, 두 반응기에 대해 슬러지 침전성을 비교한 결과, ZU는 SRT변화에 관계없이 3.4~11m/h의 침전속도를 나타내며 SVI(Sludge Volume Index)도 50~108 ml/g으로 양호한 침전상태를 보였다. 그러나 CU는 SRT 증가에 따라 슬러지 침전성이 큰 영향을 받았고 SRT 40일에서 Sphaerotilus가 우점종을 나타내었으며 이 결과, 슬러지가 전혀 침전하지 않았다.