• 한국환경보건학회지
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• 제37권2호
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• pp.124-132
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• 2011

Biofilm and aeration tank of pilot and full RABC (rotating activated Bacillus contactor) plant were analyzed to characterize and determine bacterial community structure in food wastewater treatment system at winter. Concentration of heterotrophic bacteria and Bacillus group was $10^7$ and $10^5$ CFU/ml, respectively, at biofilm of pilot-plant while others represented $10^6$ and $10^4$ CFU/ml, respectively. Five and eight phyla were detected at biofilm of pilot- and full-plant, respectively, by 16S rDNA sequencing. Biofilm of pilot-plant was dominated by ${\beta}$-Proteobacteria (38.8%), ${\gamma}$-Proteobacteria (22.4%), and Bacteroidetes (12.2%), and the most dominant genus was Zoogloeae genus (22.4%). Candidate division TM7 (12.5%) was only detected at biofilm of full-plant and it was dominated by Bacteroidetes (33.3%), ${\gamma}$-Proteobacteria (29.2%), and ${\beta}$-Proteobacteria (20.8%). Clostridium genus specific primer set enabled to detect the sequences of Clostridium genus. These suggested that anaerobic and aerobic bacteria were coexisted even from the initial period of biofilm formation and ${\beta}$-Proteobacteria, ${\gamma}$-Proteobacteria and Bacteroidetes were major phyla in biofilm of food wastewater treatment system at winter.

• 환경위생공학
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• 제11권2호
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• pp.43-52
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• 1996

Using rotating biological contactor(RBC) with artificial endogenous stage and aerobic fixed biofilm reactor(AFBR), organic material removal and biological nitrification of piggery wastewater has been studied at a pilot plant. RBC was operated in the endogenous phase at a interval of every 25 days. The concentration of COD, BOD and TKN in influent wastewater were from 2,940 to 3,800 mg/L, from 1,190 to 1,850 mg/L and from 486 to 754 mg/L respectively. The maximum active biomass content represented as VSS per unit aera was $2.0mg/cm$^{2}$ and biofilm dry density of $17mg/cm^{3}$ was observed at biofilm thickness of $900{\;}{\mu}m$. It was observed that the pilot scale RBC/AFBR process exhibited 72 percentage to 93 percentage of BOD removal, In order to obtain more than 90 percentage of BOD removal, the organic loading rate to the RBC/AFBR process should be maintained less than $0.09{\;}m^{3}/m^{2}{\cdot}day(125.9g{;\}BOD/m^{3}{\cdot}d$. The TKN removal efficiencies was from 45.5 to 90.9 percentage according to vary influent loading rate, It was estimated that the RBC/AFBR process consumed approximately 6.2 mg/L(as $CaCO_{3}$) of alkalinity per 1 mg/L of $NH_{3}$-N oxidized as the nitrification took piace.

• 산업기술연구
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• 제21권B호
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• pp.11-20
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• 2001

This laboratory study examined the impact of free chlorine residual and pipe material on the formation of biofilm in drinking water distribution pipe surfaces. Result of heterotrophic plate counts(HPC) of the biofilm in the tap water-supplied reactor averaged $2.17{\times}10^5CFU/cm^2$ on PVC and $2.43{\times}10^5CFU/cm^2$ on STS 316, respectively. HPCs on the surface exposed to the tap water containing 0.2mg/L of free chlorinne residual averaged $4.24{\times}10^4CFU/cm^2$ on PVC and $6.54{\times}10^4CFU/cm^2$ on STS 316, respectively. Average of HPC/Total direct counts in the tap water-supplied reactor ranged from 1.08%(PVC) to 1.26%(STS 316) and from 0.38%(PVC) to 0.65%(STS 316) in the reactor supplemented with disinfectant, respectively. No correlation was observed between disinfectant addition and biofilm density. With regard to the biofilm formation, little difference existed between PVC and STS 316. Yellow and red pigmented bacteria were the dominant expressions in bulk fluid, whereas non-pigmented bacteria were found dominant in the biofilm. Pink/red pigmented bacteria were found to be facultative anaerobic, while yellow pigmented bacteria and non-pigmented bacteria were found to be obligate aerobic.

• 한국환경과학회지
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• 제11권6호
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• pp.553-560
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• 2002

The research was performed to compare to the biofilm characteristics and phenol removal efficiency in RBCs(Rotating Biological Contactor) using Rhodococcus sp. EL-GT(single population) and activated sludge(mixed population) as inoculum. Both reactors showed similar tendency on variations of dry weight, thickness and dry density of biofilm. However, the growth of biofilm thickness in 3 and 4 stage of single population reactor has sustained longer than that of the mixed population reactor. Unlike the mixed population reactor, the dry density of biofilm in the single population reactor had a difference between 1, 2 stage and 3, 4 stage. The single population reactor was stably operated without the decrease of phenol removal efficiency in the range of pH 6 ~ 9 and 15mM phenol was completely degraded in these pH ranges. But in case of the mixed population reactor, the phenol degradability was dramatically decreased at over 5mM phenol concentration because of the overgrowth and detachment of its biofilm.

• Environmental Engineering Research
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• 제14권4호
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• pp.238-242
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• 2009

This study investigated the effects of organic loading rates on simultaneous carbon and nitrogen removal in an innovative fixed-film aerobic bioreactor. The fixed-film bioreactor (FFB) was composed of a two-compartment aeration tank, in which a synthetic filamentous carrier was submerged as biofilm support media, and a settling tank which polyvinylidene media (Saran) was used as settling aid for suspended solids. Three different organic loading rates, ranging from 0.92-2.02 kg chemical oxygen demand/$m^3$/day were applied by varying hydraulic retention time (HRT). The total soluble organic carbon removal efficiencies were in the range of 90-97%. The removal efficiency of ammonia was found to be in the range of 70-84%. Total nitrogen removal efficiency was found to be in the range of 40-45%, which indicates that denitrification reactions occurred simultaneously in the attached biofilm on the fibrous media in the aeration tank. The settling performance of suspended solids was significantly improved due to the presence of Saran media in the settling compartment, even for a short HRT. The fixed-film aerobic bioreactor used in this study demonstrated efficient treatment efficiency even at higher organic loading rates and at short HRTs.

• 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.

• 한국환경과학회지
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• 제22권1호
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• pp.1-6
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• 2013

A fixed biofilm reactor system composed of anaerobic, anoxic(1), anoxic(2), aerobic(1) and aerobic(2) reactor was packed with synthetic activated ceramic (SAC) media and adopted to reduce the inhibition effect of low temperature on nitrification activities. The changes of nitrification activity at different wastewater temperature were investigated through the evaluation of temperature coefficient, volatile attached solid (VAS), specific nitrification rate and alkalinity consumption. Operating temperature was varied from 20 to $5^{\circ}C$. In this biofilm system, the specific nitrification rates of $15^{\circ}C$, $10^{\circ}C$ and $5^{\circ}C$ were 0.972, 0.859 and 0.613 when the specific nitrification rate of $20^{\circ}C$ was assumed to 1.00. Moreover the nitrification activity was also observed at $5^{\circ}C$ which is lower temperature than the critical temperature condition for the microorganism of activated sludge system. The specific amount of volatile attached solid (VAS) on media was maintained the range of 13.6-12.5 mg VAS/g media at $20{\sim}10^{\circ}C$. As the temperature was downed to $5^{\circ}C$, VAS was rapidly decreased to 10.9 mg VAS/g media and effluent suspended solids was increased from 3.2 mg/L to 12.0 mg/L due to the detachment of microorganism from SAC media. And alkalinity consumption was lower than theoretical value with 5.23 mg as $CaCO_3$/mg ${NH_4}^+$-N removal at $20^{\circ}C$. Temperature coefficient (${\Theta}$) of nitrification rate ($20^{\circ}C{\sim}5^{\circ}C$) was 1.033. Therefore, this fixed film nitrogen removal process showed superior stability for low temperature condition than conventional suspended growth process.

• 생명과학회지
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• 제19권3호
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• pp.349-355
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• 2009

돈 도축 식품폐수를 처리하는 생물막 시스템인 RABC (rotating activated Bacillus contactor) 공정의 생물막과 점감식으로 운영되는 포기조의 동일한 시료를 대상으로 Biolog GN2 plate를 이용한 호기/혐기 대사지문 분석으로 다음과 같은 결과를 얻었다. 첫째 대응표본 상관관계 분석과 pairs t-test를 통하여 매일 측정값보다 일별변화량이 전반적인 군집구조의 유사성을 나타내는 것으로 판단되었다. 둘째 생물막이 포기조 시료들에 비해 높은 탄소원 이용도를 보여(p<0.01) 생물막의 높은 유기물 제거 능력을 알 수 있었고 포기조 시료사이는 이용된 탄소원의 상관관계가 높았고(78%) 활성정도도 비슷하였다(p=0.287). 셋째 활발하게 이용된 탄소원의 종류는 시료별로 차이를 보여 활성을 보이는 군집이 각 처리단계 별로 변화하는 것으로 판단되었다. 마지막으로 같은 시료라도 호기/혐기 조건에 따라 대사지문에 차이를 보여 미호기성 및 혐기성 군집구성원에 의한 활성 차이를 확인하였다. 향후 대사지문(metabolic fingerprinting)을 통한 활성군집 비교에 일별변화량과 혐기조건 분석을 병행하면 더욱 풍부한 분석이 가능할 것이다.

• KSBB Journal
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• 제17권1호
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• pp.80-87
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• 2002

유기물 제거뿐만 아니라 안정적으로 질소와 인의 동시 제거를 위한 순환식 생물막 반응기를 제작, 운전하여 최적의 운전 인자를 도출하고, 질소 제거의 텃 번째 단계인 질산화 및 뒤이은 탈질에 관여하는 미생물들의 군집 구조 분석을 수행하였다. 유기물 제거와 질소와 인의 동시 제거를 위한 순환식 생물막 반응기는 143일 동안 운전되었다. 이 결과 $COD_{cr},\;BOD_5$, SS의 경우 각각 88, 88, 97%의 평균 제거효율을 보였다 이 기간 중 질산화율은 약 96% 정도로 유입 ${{NH_4}^{+}}_{-}N$의 대부분이 제거됨을 보였다. 하지만 탈질율은 평균 45% 정도로 나타났다. 반응기로 유입되는 총 인의 경우 약 44%가 제거되었다. 질소제거의 첫 번째 단계인 질산화가 일어나는 호기성 반응조 내 질산화 미생물의 경우 FISH 관찰 결과, 주요 암모니아 산화균 및 아질산 산화균으로는 Nitrosomonas spp.와 Nitrospira sap.가 관찰되었다. 또한 탈질 반응이 일어나는 준혐기성 반응조에서는 Rhodobacter, Rhodovulum, Roseebacter 그리고 Paracoccus 속에 속하는 탈질 미생물들이 전체 미생물의 약 10~20% 정도를 차지하며 분포하였다.

• 한국물환경학회지
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• 제21권6호
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• pp.624-629
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• 2005

The purpose of this study is to investigate the performance of nitrogen removal using autotrophic microorganism in the Membrane-Attached Biofilm Reactor (MABR). The treatment system consists of an aerobic MABR (R1) for nitrification and an anaerobic MABR (R2) for hydrogenotrophic denitrification. Oxygen and hydrogen were supplied through the lumen of hollow-fiber membranes as electron acceptor and donor, respectively. In phase Ι, simultaneous organic carbon removal and nitrification were carried out successfully in R1. In phase II, to develop the biofilm on the hollow-fiber membrane surface and to acclimate the microbial community to autotrophic condition, R1 and R2 were operated independently. The MABRs, R1 and R2 were connected in series continuously in phase III and operated at HRT of 8 hr or 4 hr with $NH_4{^+}-N$ concentration of influent, from 150 to 200 mgN/L. The total nitrogen removal efficiency reached the maximum value of 99% at the volumetric nitrogen loading rate of $1.20kgN/m^3{\cdot}d$ in the combined MABR system with R1 and R2. The results in this study demonstrated that the combined MABR system could operate effectively for the removal of nitrogen in wastewater not containing organic materials and can be used stably as a high rate nitrogen removal technology.