• KSBB Journal
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• v.15 no.5
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• pp.514-520
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• 2000

Simultaneous nitrification and denitrification of ammonia and organic compounds-containing wastewater were performed in a fluidized bed biofilm reactor with polysulfone(PS) hollow fiber as a double layer biomass carrier. The PS hollow fiber fragment has both aerobic and anoxic environments for the nitrifiaction and denitrification at the shell and lumen-side respectively. The reactor system showed about 80% nitrification efficiency stably throughout the ammonia load conditions applied in the experiment. Denitrification efficiency depended on organic load and C/N ratio. High free ammonia concentration and low dissolved oxygen resulted in nitrite accumulation which leads to enhance organic carbon efficiency in denitrification when compared to nitrate denitrification. The simultaneous nitrification and denitrification reactor system has an economic advantages in reduced chemical cost of organic carbon for denitrification as well as compact reactor configuration.

• Membrane Journal
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• v.28 no.3
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• pp.196-204
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• 2018

The anaerobic fluidized bed bioreactor (AFBR) treating synthetic wastewater to simulate domestic sewage was operated under GAC fluidization to provide high surface area for biofilm formation. Although the AFBR achieves excellent COD removal efficiency due to biological activities, concerns are still made with nutrient such as nitrogen remaining in the effluent produced by AFBR. In this study, forward osmosis membrane was applied to treat the effluent produced by AFBR to investigate removal efficiency of total nitrogen (TN) with respect to the draw solution (DS) such as NaCl and glucose. Permeability of FO membrane increased with increasing DS concentration. About 55% of TN removal efficiency was observed with the FO membrane using 1 M of NaCl of draw solution, but almost complete TN removal efficiency was achieved with 1 M of glucose of draw solution. During 24 h of filtration, there was no permeate flux decline with the FO membrane regardless of draw solution applied.

• Journal of Environmental Science International
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• v.3 no.3
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• pp.263-271
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• 1994

A detachment of biofilm was investigated in an inverse fluidized bed biofilm reactor(IFRBR). The biofilm thickness, 5 and the bioparticle density, Pm were decreased by the increase of Reynolds number, Re and the decrease of biomass concentration, h. The correlations were expressed as $\delta$=6l.6+16.33$b_c$-0.004Re and Ppd=0.3+0.027$b_c$- 2.93x$l0^{-5}$ no by multiple linear regression analysis method. Specific substrate removal rate, q was derived by F/M ratio and biofilm thickness as q=0.44.+0.82F/M-5.Ix10$-4^{$\delta$}$. Specific biofilm detachment rate, bds was influenced by FIM ratio and Reynolds number as $b_{ds}$=-0.26+0.26F/M+ 2.17$\times$$10^{-4}$Re. Specific biofilm deachment rate in an IFBBR was higher than that in a FBRR(fluidized bed biofilm reactor) because of the friction between air bubble and the bioparticles.

• Journal of Environmental Science International
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• v.4 no.3
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• pp.69-69
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• 1995

• Journal of Environmental Science International
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• v.4 no.3
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• pp.221-228
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• 1995

Stability of reactor and effect on biofilm characteristics were investigated by varying the hydraulic residence time in an inverse fluidized bed biofilm reactor(IFBBR). The SCOD removal efficiency was maintained above 90 % in the HRT range of 12hr to 2hr, but the TCOD removal efficiency was dropped down to 50% because of biomass detachment from overgrown bioparticles. The reactor was stably operated up to the conditions of HRT of 2hr and F/M ratio of 4.5kgCOD/$m^3$/day, but above the range there was an abrupt increase of filamentous microorganisms. The optimum biofilm thickness and the biofilm dry density in this experiment were shown as $200\mu\textrm{m}$ and $0.08 g/cm^3$, respectively. The substrate removal rate of this system was found as 1st order because the biofilm was maintained slightly thin by the increased hydraulic loading rate.

• Journal of Environmental Science International
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• v.3 no.1
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• pp.49-56
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• 1994

Effect of the liquid circulation velocity on the biofilm development was investigated in an inverse fluidized bed biofilm reactor(IFBBR). To observe the effect of the influent COD concentration on biofilm simultaneously, the influent COD value was adjusted to 1000mg/1 f for 1st reactor, and 2500mg/l for 2nd reactor. The liquid circulation velocity was adjusted by controlling the initial liquid height. As the liquid circulation velocity was decreased, the settling amount of biomass was increased and the amount of effluent biomass was decreased. Since the friction of liquid was decreased by the decrease of liquid circulation velocity, the biofilm thickness was increased and the biofilm dry density was decreased. In the 1st reactor the SCOD removal efficiency was constant regardless of the variation of the liquid circulation velocity, but it was increased by the decrease of the liquid circulation velocity because of more biomass population in 2nd reactor.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.3
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• pp.45-53
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• 1987

The purpose of this research was to study the kinetics of a packed bed aerobic biofilm process. Experiments were carried out by feeding an aerated packed bed reactor with a synthetic wastewater. The reactor packed with glass beads as media had a nominal hydraulic detention time of 5 hours. The flow pattern in the reactor was determined by a tracer test using a NaCl solution to be a completely-mixed type. The results of the research showed that the F/M ratio in the reactor was almost constant since the the biomass increased due to the growth of biofilm as the volumetric organic loading increased. It was also proved theoretically and experimentally that packed bed aerobic biofilm process could be analyzed by the kinetics of completely-mixed activated sludge process with sludge recycle.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.11a
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• pp.233-236
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• 2004

• Membrane Journal
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• v.34 no.2
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• pp.96-104
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• 2024

Antibiotics is one of the emerging pollutants found in various water sources as well as wastewater due to its excessive use. Different techniques are available for treating antibiotics contaminants in water such as advanced oxidation process and biological treatment etc. These two processes are ineffective, and the generation of side products makes this process more complicated. Membrane technology is another alternative for the removal of contaminants. To improve the removal of antibiotics and their resistant gene, membrane bioreactors are modified with NaClO and carbon materials. The generation of abundant reactive species is active against the antibiotic's resistant genes.

• KSBB Journal
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• v.22 no.4
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• pp.191-196
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• 2007

This study used biofilm process, which needs simple operation, maintenance and smaller facility area than conventional activated sludge process with the small plant operation, in the treatment of increasing sewage with the rapid industrial growth. The reactor used in this study consists of one anaerobic and one aerobic chamber filled with waste ceramic and waste vinyl as media and the treated sewage was from restaurant source. The experiment was scaled up from lab. to pilot scale and lasted for about 100 days. We focused on the removal efficiency of organics, nitrogen and phosphorus with constant HRT and continuous aeration. The removal efficiency of $BOD_5$ and SS were 94.33% and 87.77% respectively, which was a satisfaction level. However the removal efficiency of $COD_{Cr}$ was 81.46% somewhat below the desired level of 90%, and that of T-N and T-P showed 71.92% and 21.10% respectively, that was below the expected value. The removal efficiency of $COD_{Cr}$ and T-N in the pilot scale was about 10% low compared with the lab.-scale.