• Journal of Environmental Health Sciences
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• v.37 no.2
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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.

• Journal of environmental and Sanitary engineering
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• v.11 no.2
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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.

• Journal of Industrial Technology
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• v.21 no.B
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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.

• Journal of Environmental Science International
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• v.11 no.6
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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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• v.14 no.4
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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.

• Journal of Animal Environmental Science
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• v.13 no.3
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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 Environmental Science International
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• v.22 no.1
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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.

• Journal of Life Science
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• v.19 no.3
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• pp.349-355
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• 2009

Metabolic fingerprinting of microbial communities was investigated with Biolog GN2 plates using samples of biofilm and aeration tanks from an RABC (rotating activated Bacillus contactor) system - an advanced wastewater treatment system for the food wastewater of pig slaughterhouses. Aerobic and anaerobic results revealed the following four aspects. First, simple matching and pairs t-test of daily variation showed more defined qualitative and quantitative relatedness of active microbial communities than that of mere optical densities. Second, metabolic potentials were higher in biofilm than in aeration tanks (p<0.01), meaning higher activity of biofilm. Third, two aeration tanks showed the highest similarity (78%) and similar metabolic power (p=0.287). However, actively used carbon sources were different among samples, signifying change of active communities at each wastewater treatment step. Finally, aerobic and anaerobic metabolic fingerprinting patterns were different for the same samples representing activities of microaerophilic and/or anaerobic communities. These results suggest that daily variation and anaerobic incubation would help in the comparison of metabolic fingerprintings.

• KSBB Journal
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• v.17 no.1
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• pp.80-87
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• 2002

Laboratory scale aerobicfanaerobic biofilm reactor was used for simultaneous and stable removal of organics, N and P components to investigate optimum design and operation parameters and to analyze the microbial distribution and consortium structure of nitrification and denitrification bacteria in aerobic and anaerobic biofilm systems. The biofilm reactor was successfully operated for 143 days to show $COD_{cr},\;BOD_5$, SS removal efficiencies of 88, 88, and 97%, respectively. During the experiment period, almost complete nitrification efficiency of 96% was achieved. Denitrification efficiency was about 45% without addition of any external carbon sources. In case of total phosphorus removal, 74% of the inlet phosphorus was removed. Fluorescence in situ hybridization (FISH) results showed that most of the ammonia oxidizing bacteria in the aerobic nitrification zone was found to be Nitrosomonas species while Nitrospira was the representative nitrite oxidizing bacteria. For the denitrification, Rhodobacter, Rhodovulum, Roseebacter and Paracouus were the dominant denitrification bacteria which was 10 to 20% of the total bacteria in numbers.

• Journal of Korean Society on Water Environment
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• v.21 no.6
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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.