• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.172-179
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• 1999

In this research, biological treatability test was conduced using seawater flocculated tannery wastewater by fixed biofilm reactor. During one cycle, the removal efficiency of organic corbon obtained with fixed biofilm process for treating tannery wastewater was considerably greater than that with activated sludge process. As the hydraulic retention time increased form 0.5day to 4day, removal efficiency of organic carbon was increased from 72% to 87.3%. Attached biomass in media increased with influent organic loading up to 29g MLSS/L, that could reduce the specific organic loading rate. The continual measurement of attached biomass was possible for the operation of the biofilm reactor. Equal and low nitrication rates were observed in both suspended growth activated sludge process and fixed biofilm process, despite commercial nitrifier was seeded. Through the process of treating the tannery wastewater, EC50 values which is measured by the use of Ceriopdaphnia dubia, were decreased to the extent of 50% after treatment of seawater flocculation and of 83% after biological treatment, respectively, compared to those of the untreated wastewater.

• Journal of environmental and Sanitary engineering
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• v.10 no.3
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• pp.67-77
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• 1995

This study was performed for minimization of excessive biofilm effects at the high strength organic wastewater treatment. As a results of biofilm attachment experiment using piggery wastewater, aggravation of water quality due to excessive biofilm showed after 15 days of operating times.4 excessive biofilm phase, the equivalent biofilm thickness and VSS contents per unit aura were observed in the range of 1,100 to $1,200{\mu}m$ and 2.5 to 3.0mg $VSS/cm^{2}$, respectively. In the aerobic fixed biofilm reactor/anoxic fixed biofilm reactor(AFBR/ANFBR) process with endogenous respiration phase, the BOD removal efficiency was obtained more than 90 percentage at the surface loading rate and volumetric loading rate of the AFBR maintained less than 17 g $BOD/m^{2}{\cdot}$day and 1.7kg $BOD/m^{3}{\cdot}$day, respectively. The removal efficiency of TKN and $NH_{3}$-N at the loading rates below 5.60g $NH_{3}-N/m^{2}{\cdot}day$ and 0.56kg $NH_{3}-N/m^{3}{\cdot}$day were above 76 percentage and 82 percentage, respectively. In order to reduced sludge production rate and aggravation of water quality, endogenous respiration phase was accepted at first AFBR reactor. As a results of this operating condition, sludge production was minimized and removal efficiency was maintained stability.

• Journal of Environmental Science International
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• v.10 no.4
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• pp.281-286
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• 2001

Wastewater from the pigment industry has high levels of organics and is known as hardly biodegradable. The objective of this study is to evaluate the applicability of aerobic fixed-bed boifilm reactor packed with ceramic support carrier for the pigment wastewater treatment. Orange 2(widely used azo pigment) adsorption experiment onto biofilm and activated sludge, and continuous treatment experiments were performed. In batch adsorption experiment, maximum adsorption quantity of biofilm was at least two times higher than that of activated sludge. In continuous experiment using aerobic fixed-bed biodilm reactor, the influent concentration of COD and Orange 2 were 75~500mg/${\ell}$(0.45~3.00kg COD/$m^3.day), 5~50mg/$\ell$(0.03~0.30kg Orange 2/$m^3$.day), respectively. At a COD loading rate 2.5kg COD/$m^3$.day and Orange 2 loading rate of 0.18kg Orange 2/$m^3$.day, removal efficiency of COD and Orange 2 were over 95%, 97%, respectively.

• Journal of Industrial Technology
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• v.16
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• pp.5-11
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• 1996

While the enhanced biological phosphorus removal(EBPR), in anaerobic/aerobic condition, was known to remove phosphorus by means of metabolism of poly-P microorganisms, the phosphorus removed could be released in the form of ortho-P in the aerobic fixed biofilm reactor. This study was initiated to investigate the cause of ortho-P release in the aerobic fixed biofilm reactor. The resutls indicated that the phosphorus release was caused by autooxidation. The synthesis and release of phosphrous were related to the ORP and the boundary value for the phase change was about 170mV. In the synthesis phase, the phosphorus removal rate per COD removed was $0.023mgP_{syn}/mgCOD_{rem}$. The phosprous contents of the microorganism were 4.3 ~ 6.0% on a dry weight basis.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.278-281
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• 2001

A fixed bed biofilm reactor filled with ceramic media were used to remove nitrogen by selective nitrification (ammonium to nitrite). The effects of experimental conditions (nitrogen load, dissolved oxygen, nitrite ratio, C/N ratio) on denitrification were investigated. The reactor showed more than 80% average T-N removal efficiencies at T-N loading in the range of $1.1{\sim}3.3$ kg $T-N/m^3{\cdot}d$ C/N at the C/N ratio of 1. T-N removal efficiencies increased as nitrite ratio.

• Journal of Korean Society of Water and Wastewater
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• v.7 no.1
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• pp.37-45
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• 1993

This research was performed to examined the applicability of a fixed-biofilm process for the wastewater treatment of military installations. Utilizing plastic net media, synthetic wastewater-average $BOD_5$ cocentration was $192mg/l$ treated in the three sets of reactors that have 8 hours, 6 hours, and 4 hours of hydraulic retention time. The results of this experiment showed that the biofilm was not detached easily, and the reactor was not closed by excess biomass. The average soluble $BOD_5$ concentrations of effluent were $6.0mg/l$ with 8 hours of retention time, $11.3mg/l$ with 6 hours of retention time, and $19.4mg/l$ with 4 hours of retention time. Especially it was reduced to $5.7mg/l$ in the second stage reactor with 4 hours of retention time. These resulted that the fixed-biofilm process could be adapted for the treatment of military installation wastewater.

• Journal of Life Science
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• v.9 no.6
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• pp.698-703
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• 1999

For the nitrate removal in recirculating aquaculture system, a denitrifying bacterium, Pseudomonas fluorescens, was isolated from municipal sewage and the cells were immobilized in modified-polyvinly alchol (PVA) gel beads. The immobilized cells in both the fixed-and fluidized-bed reactors showed 98% of denitrification efficiency with 6hr HRT, and the removal efficiency of total organic carbon (TOC) was above 90%. Form scanning electron microscopy (SEM) observation, it was known that biofilm formed in fixed-bed reactor was thicker than that formed in fluidized-bed reactor as operation time passed.

• KSBB Journal
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• v.6 no.2
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• pp.115-121
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• 1991

A number of experiments were conducted in order to investigate the COD removal rate according to the biofilm thickness in a Fluidized-Bed Biofilm Reactor(FBBR). The following conditions were fixed during the experiments: superficial upflow velocity was 0.47cm/sec, operating temperature was $22{\pm}1{\circ}C$ and pH was about $7{\pm}0.1$. The synthetic wastewater based on glucose was used as a substrate. The COD removal efficiencies were shown as 73% and 95%, respectively, when organic loading rate was increased from $10kgCOD\;/\;{\textrm{m}^3}$.day to $80kgCOD\;/\;{\textrm{m}^3}$.day. Andrew's model of substrate removal rate which was commonly used in fixed-biofilm reactor was transformed and applied in this FBBR experiment to predict substrate removal rate and gave 85% agreement with the experimental values.

• Journal of Environmental Health Sciences
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• v.28 no.3
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• pp.55-63
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• 2002

This study was carried out to treat textile wastewater using anaerobic sludge and aerobic fixed-bed biofilm reactor immobilized with Bacillus sp. dominated activated sludge(Bacillus sp. fraction : 81.5%). The range of influent con-centration of SCOD and soluble color were 1032-1507 mg/1, and 1239-1854 degree, respectively. Continuous treatment experiments were performed with variation of textile wastewater ratio at a same HRT. When textile wastewater ratio was 100%(HRT : 24 hours), The removal efficiency of SCOD and soluble color were 88% and 78%, respectively. When compare aerobic reactor of this study that was immobilized with Bacillus sp. dominated activated sludge to other study that was immobilized with activated sludge, SCOD and soluble color removal efficiency of this study showed a little higher efficiency than immobilized with activated sludge. The Bacillus sp. fraction of initial condition was 81.5%), but the fraction after operation was decreased to 31.8%).

• Journal of Wetlands Research
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• v.4 no.1
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• pp.87-95
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• 2002

The objective of this study is to treat contaminated stream by using a UFBR(upflow fixed biofilm reactor) packed with waste-concrete media. This system was tested from June 1999 to January 2000. Over $20.0^{\circ}C$, $COD_{cr}$ removal efficiency did not affected with organic loading rate while, $COD_{cr}$ removal efficiency decreased about 7% with decrease of temperature from $27.0^{\circ}C$ to $8.7^{\circ}C$. Under $16^{\circ}C$, TKN removal efficiency was affected with TKN loading rate. The proposed model apply to mass balance equation of fixed biofilm reactor for predicting effluent was well satisfied with measured value($R^2=0.94$).