• Journal of Microbiology and Biotechnology
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• 제21권2호
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• pp.115-123
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• 2011

To investigate the effects of pipe materials on biofilm accumulation and water quality, an annular reactor with the sample coupons of four pipe materials (steel, copper, stainless steel, and polyvinyl chloride) was operated under hydraulic conditions similar to a real plumbing system for 15 months. The bacterial concentrations were substantially increased in the steel and copper reactors with progression of corrosion, whereas those in stainless steel (STS) and polyvinyl chloride (PVC) reactors were affected mainly by water temperature. The heterotrophic plate count (HPC) of biofilms was about 100 times higher on steel pipe than other pipes throughout the experiment, with the STS pipe showing the lowest bacterial number at the end of the operation. Analysis of the 16S rDNA sequences of 176 cultivated isolates revealed that 66.5% was Proteobacteria and the others included unclassified bacteria, Actinobacteria, and Bacilli. Regardless of the pipe materials, Sphingomonas was the predominant species in all biofilms. PCR-DGGE analysis showed that steel pipe exhibited the highest bacterial diversity among the metallic pipes, and the DGGE profile of biofilm on PVC showed three additional bands not detected from the profiles of the metallic materials. Environmental scanning electron microscopy showed that corrosion level and biofilm accumulation were the least in the STS coupon. These results suggest that the STS pipe is the best material for plumbing systems in terms of the microbiological aspects of water quality.

• 한국식품과학회지
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• 제25권3호
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• pp.210-213
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• 1993

본 실험의 목적은 공극률과 상향유속의 관계에서 세입자의 유동특성을 고찰하는 데 있다 Column 내경은 유동층의 유속과 공극률과의 관계에 큰 영향을 미치지 못했으며 유속과 공극률과의 관계는 다음과 같다. $\frac{u}{u_t}={\varepsilon}^{3.703}$----모래$\frac{u}{u_t}={\varepsilon}^{3.5665}$----이온 교환수지$\frac{u}{u_t}={\varepsilon}^{4.066}$---GAC 또 유동층 매질입자는 구형을 사용하는 것이 일정유속에서 공극률을 낮게 유지할 수 있어 좋았고 실제로 미생물막 유동층 반응기에서는 미생물막이 매질에 부착되면 비중이 감소하므로 매질의 비중이 높을수록 유동층을 유지하기가 쉽다.

• 산업기술연구
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• 제16권
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• pp.51-60
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• 1996

This research was performed for the fundamental data using a advanced treatment process of piggery wastewater. Characteristics of influent wastewater was divided with various methods in fixed biofilm batch reasctor. Fractons of organic were divided into readily biodegradable soluble COD(Ss), slowly biodegradable COD(Xs), nonbiodegradable soluble COD($S_I$), and nonbiodegradable suspended COD($X_I$). Experimental results were summerized as following : i) biodegradable organics fraction in piggery wastewater was about 88.1 percent, and fraction of readily biodegradable soluble COD was about 66.1 percent. ii) Fractions of nonbiodegradable soluble COD was 11~12 percent, and soluble inert COD by metabolism was producted about 6~8 percent. iii) Active biomass fraction of attached biofilm was about 54.7 percent, and substrate utilization rate and maximum specific growth rate of heterotrophs were $8.315d^{-1}$ and $3.823d^{-1}$, respectively.

• 한국축산시설환경학회지
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• 제13권3호
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• pp.219-232
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• 2007

Odors from manures are a major problem for livestock production. The most significant odorous compounds in animal manure a.e volatile fatty acids(VFAs). This work reviews the VFAs from the anaerobic sequencing biofilm batch reactor(ASBBR), anaerobic sequencing batch reactor(ASBR), solid compost batch reactor(SCBR), and aerobic sequencing batch reactor(SBR) associated with the animal manure biological treatment. First, we describe and quantify VFAs from animal manure biological treatment and discuss biofiltration for odor control. Then we review certain fundamentals aspects about Anaerobic and aerobic SBR, composting of animal manure, manure compost biofilter for odorous VFAs control, SBR for nitrogen removal, and ASBR for animal wastewater treatment systems considered important for the resource recovery and air quality. Finally, we present an overview for the future needs and current experience of the biological systems engineering for animal manure management and odor control.

• Journal of Microbiology and Biotechnology
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• 제16권3호
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• pp.399-407
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• 2006

In this study, an electrical conductive carbon fiber was used as a biofilter matrix to electrochemically improve the biofilter function. A bioreactor system was composed of carbon fiber (anode), titanium ring, porcelain ring, inorganic nutrient reservoir, and VOC reservoir. Electric DC power of 1.5 volt was charged to the carbon fiber anode (CFA) to induce the electrochemical oxidation potential on the biofilter matrix, but not to the carbon fiber (CF). We tested the effects of electrochemical oxidation potential charged to the CFA on the biofilm structure, the bacterial growth, and the activity for metabolic oxidation of VOCs to $CO_2$, According to the SEM image, the biofilm structure developed in the CFA appeared to be greatly different from that in the CF. The bacterial growth, VOCs degradation, and metabolic oxidation of VOCs to $CO_2$ in the CFA were more activated than those in the CF. On the basis of these results, we propose that the biofilm structure can be improved, and the bacterial growth and the bacterial oxidation activity of VOCs can be activated by the electrochemical oxidation potential charged to a biofilter matrix.

• 대한소아치과학회지
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• 제42권4호
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• pp.302-311
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• 2015

본 연구는 Planktonic growth inhibition test와 CDC Biofilm Reactor를 사용한 Biofilm assay를 통해 S-PRG filler를 함유하는 치면열구전색제의 S. mutans에 대한 항미생물 효과를 기존의 치면열구전색제와 비교하고자 하였다. S-PRG 필러를 함유하는 치면열구전색제인 BeautiSealant, 불소를 방출하는 치면열구전색제인 Clinpro$^{TM}$ sealant, 불소 미방출 치면열구전색제인 Concise$^{TM}$ sealant를 실험군으로 선정하였다. 성장억제평가를 위해 치면열구전색제를 사용하지 않은 군을 음성 대조군으로 설정하였으며, 3개의 실험군 모두 대조군보다 유의할 정도로 낮은 집락 형성 단위를 보였고, Clinpro$^{TM}$ sealant가 BeautiSealant와 Concise$^{TM}$ sealant보다 유의할 정도로 낮은 집락 형성 단위를 보였다. BeautiSealant와 Concise$^{TM}$ sealant 군간에는 유의한 차이가 관찰되지 않았다. 바이오 필름 평가에서도 Clinpro$^{TM}$ sealant군이 BeautiSealant와 Concise$^{TM}$ sealant군들에 비해 유의할 정도로 낮은 집락 형성을 보였으며, BeautiSealant와 Concise$^{TM}$ sealant 군간에 유의한 차이는 관찰되지 않았다. 본 연구 결과 S-PRG filler를 포함하는 치면열구전색제인 BeautiSealant는 기존의 불소방출 치면열구전색제에 비하여 낮은 항미생물 효과와 높은 바이오 필름 형성능을 보였다.

• Journal of Microbiology and Biotechnology
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• 제18권8호
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• pp.1459-1469
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• 2008

Using a rotating biological contactor modified with a sequencing bath reactor system (SBRBC) designed and operated to remove phosphate and nitrogen [58], the microbial community structure of the biofilm from the SBRBC system was characterized based on the extracellular polymeric substance (EPS) constituents, electron microscopy, and molecular techniques. Protein and carbohydrate were identified as the major EPS constituents at three different biofilm thicknesses, where the amount of EPS and bacterial cell number were highest in the initial thickness of 0-100${\mu}m$. However, the percent of carbohydrate in the total amount of EPS decreased by about 11.23%, whereas the percent of protein increased by about 11.15% as the biofilm grew. Thus, an abundant quantity of EPS and cell mass, as well as a specific quality of EPS were apparently needed to attach to the substratum in the first step of the biofilm growth. A FISH analysis revealed that the dominant phylogenetic group was $\beta$- and $\gamma$-Proteobacteria, where a significant subclass of Proteobacteria for removing phosphate and/or nitrate was found within a biofilm thickness of 0-250${\mu}m$. In addition, 16S rDNA clone libraries revealed that Klebsiella sp. and Citrobacter sp. were most dominant within the initial biofilm thickness of 0-250${\mu}m$, whereas sulfur-oxidizing bacteria, such as Beggiatoa sp. and Thiothrix sp., were detected in a biofilm thickness over 250${\mu}m$. The results of the bacterial community structure analysis using molecular techniques agreed with the results of the morphological structure based on scanning electron microscopy. Therefore, the overall results indicated that coliform bacteria participated in the nitrate and phosphorus removal when using the SBRBC system. Moreover, the structure of the biofilm was also found to be related to the EPS constituents, as well as the nitrogen and phosphate removal efficiency. Consequently, since this is the first identification of the bacterial community and structure of the biofilm from an RBC simultaneously removing nitrogen and phosphate from domestic wastewater, and it is hoped that the present results may provide a foundation for understanding nitrate and phosphate removal by an RBC system.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.115-115
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• 2005

• 상하수도학회지
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• 제23권1호
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• pp.129-135
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• 2009

PPCP (pharmaceuticals and personal care products) is known as micropollutant that is released from wastewater treatment plant. Research represents that these contaminants have increased in the last 10 years. This study tries to make four different trickling filter systems using plastic fiber media to remove PPCP such as acetaminophen, ibuprofen, caffeine. The results of the experiment that compares the process efficiencies of four different systems (A, B, C and D) using HBC media show that almost all the reactor has around 95% removal efficiency. Slope type HBC reactor has twice higher efficiency rather than submerged type reactor to remove PPCP in water system. In 8 hours, 89% of acetaminophen, ibuprofen, caffeine are removed in slope type reactor while 39% of them in submerged type.

• 대한환경공학회지
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• 제29권1호
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• pp.106-112
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• 2007

Ammonia oxidizing bacteria(AOB)는 $NH_4^+-N$을 $NO_2^--N$으로 산화시키며, 생물학적 질산화 단계에서 율속 단계로 작용하기 때문에 중요한 미생물이다. AOB의 성장은 용존산소, 온도, pH 등의 환경 인자에 영향을 받는다. 본 연구에서는 DO 농도가 AOB에 미치는 영향을 조사하기 위해 세라믹 메디아가 충전된 4개의 호기성 생물막 반응기의 DO 농도를 각각 1, 3, 5, 7 mg/L로 운전하였다. 운전결과, 5 mg/L 이상에서 안정적인 질산화 효율을 얻을 수 있었다. AOB의 특성을 조사하기 위해 AOB의 16S rRNA와 amoA gene을 target으로 PCR을 이용한 DGGE와 cloning을 실시하였으며, 이들의 활성을 조사하기 위해 INT-DHA를 측정하였다. DO 농도 변화에 따른 각 반응기별 질산화 효율에 차이가 있었음에도 불구하고, DGGE 및 cloning 결과, AOB 군집 및 Nitrosomonas sp.의 비율의 변화는 거의 없었다. DO 농도가 감소함에 따라 AOB의 활성도가 감소한다는 것을 INT-DHA 측정으로 확인할 수 있었다. 따라서 DO 농도는 AOB 군집의 변화 보다는 활성에 영향을 미치는 것으로 판단되었다.