• Proceedings of the Membrane Society of Korea Conference
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• 2003.05a
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• pp.31-38
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• 2003

A pilot scale biofilter pretreatment-microfiltration system (BF-MF) was operated to investigate the effect of biofilter treatment in fouling reduction of microfiltration. Biofiltration was expected to reduce the membrane fouling by removal of turbidity and metal oxides. The hollow-fiber MF module with a nominal pore size of 0.1$\mu$m and a surface area of 8m$^2$ was submerged in a filtration tank and microfiltration was operated at a constant flux of 0.5 m/d. Biofiltration using polypropylene pellets was performed at a high filtration velocity of 320 m/d. Two experimental setups composed of MF and BF/MF, i.e., without and with biofilter pretreatment, were compared. Throughout the experimental period of 9 months, biofilter pretreatment was effective to reduce the membrane fouling, which was proved by the result of time variations of trans-membrane pressure and backwash conditions. The turbidity removal rate by biofiltration varied between 40% to 80% due to the periodic washing for biofilter contactor and raw water turbidity. In addition to turbidity, metals, especially Mn, Fe and Al were removed effectively with average removal rates of 89.2%, 67.8% and 64.9%, respectively. Further analysis of foulants on the used membranes revealed that turbidity and metal removal by biofiltration was the major effect of biofiltration pretreatment against microfiltration fouling.

• KSBB Journal
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• v.17 no.2
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• pp.115-120
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• 2002

Biofiltration is a bioprocess treating volatile organic compounds (VOCs) in order to convert the VOCs to harmless products. This review on biofiltration is intended to provide an engineering concept such as removal efficiency, maximum load, elimination capacity and so on. Besides, modeling concept of biofilter is also supplied for designing biofilter system. Quantitative data generated in our research group is shown to explain the engineering concept as well as the modeling idea.

• Journal of Environmental Health Sciences
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• v.29 no.4
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• pp.4-9
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• 2003

Biofiltration can effectively remove both organic and inorganic air pollution compounds from both industrial and public sources. However, for the optimal biofiltration performance, it is necessary to gain a better understanding of the inner environment and destruction mechanisms within a biofilter. The effects of operational factors on removal efficiency was studied. Generally, removal efficiency decreases as the loading rate increases. Temperature, as one of the key factors that affect biofiltration design and performance, was also investigated. Conceptually, the biofilter reactor of this paper was divided into five different consecutive stages. The more ethylbenzene COD degraded at each stage, the higher the temperature increases observed compared to the temperatures of the previous stages. It was observed that for every 1 kg of ethylbenzene COD degraded per cubic meter of biofilter media, there was generally a 0.41$^{\circ}C$ increase in the temperature of that stage.

• Journal of Microbiology
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• v.38 no.1
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• pp.31-35
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• 2000

A suitable packing material for biofiltration of monoaromatic solvent vapors was selected among various types of packing materials such as peat, bark chips, vermiculite, and Hydroballs. A previously isolated strain, Pseudomonas pseudoalcaligenes BTXO2, which could utilize toluene, m-and p-xylene as carbon and energy sources was used as a biofilter inoculum. Four glass biofilters (6 cm dia. x 60 cm) were individually packed with each of the packing materials and solvent vapors were passed through the columns. During three weeks of peat biofilter operation, average removal efficiencies of toluene, m-and p-xylene were 90.4%, 95.3%, and 82.1%, respectively. With the other packings, the efficiencies were in the range of 10.1 to 58.6％ which were significantly lower than those of the peat biofilter. The peat biofilter was continually operated for approximately nine months and the biofilter sustained its degradation activity during the operation period with minimal maintenance. At steady state, average removal rates of toluene, m- and p-xylene vapors were estimated as 14.2, 5.5, and 8.1 g m$\^$-3/ packing h$\^$-1/, respectively.

• Journal of Microbiology and Biotechnology
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• v.17 no.12
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• pp.1976-1982
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• 2007

In the current studies, we characterized the degradation of a hot mixture of benzene and toluene (BT) gases by a thermophilic biofilter using polyurethane as a packing material and high-temperature compost as a microbial source. We also examined the effect of supplementing the biofilter with yeast extract (YE). We found that YE substantially enhanced microbial activity in the thermophilic biofilter. The degrading activity of the biofilter supplied with YE was stable during long-term operation (approximately 100 d) without accumulating excess biomass. The maximum elimination capacity ($1,650\;g{\cdot} m^{-3}{\cdot} h^{-1}$) in the biofilter supplemented with YE was 3.5 times higher than that in the biofilter without YE ($470\;g{\cdot} m^{-3}{\cdot} h^{-1}$). At similar retention times, the capacity to eliminate BT for the YE-supplemented biofilter was higher than for previously reported mesophilic biofilters. Thus, thermophilic biofiltration can be used to degrade hydrophobic compounds such as a BT mixture. Finally, 168 rDNA polymerase chain reaction-DGGE (PCR-DGGE) fingerprinting revealed that the thermophilic bacteria in the biofilter included Rubrobacter sp. and Mycobacterium sp.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.7
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• pp.46-52
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• 2002

Manure compost biofilter for reducing ammonia emissions at the active stage of a semi air tight and agitated bed composting of hog manure amended with sawdust were evaluated in the practical composting plant(75 m 5 m $\times$1.4 m deep). During 55 days of composting and biofiltration process, the manure compost biofilter had a ammonia reduction of 91 to 98%. Results showed that the active stage of composting maintained temperatures between 40 and 7$0^{\circ}C$ and fluctuated greatly the ammonia concentrations between 100 and 300 ppm. Ammonia concentrations in manure compost biofiltration reached within a moderate range (2-18 ppm).

• Environmental Engineering Research
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• v.22 no.2
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• pp.203-209
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• 2017

Innovations in the biofiltration process can provide effective solutions to overcome crucial water pollution problems. The elimination of pollutants is a result of the combined effects of biological oxidation, adsorption and filtration processes. This research aims to evaluate the performance of quartz sand biofiltration for removing total suspended solids, turbidity, color, organic matter, and ammonium from polluted river water and develop an empirical model for designing quartz sand biofilters for the treatment of polluted river water. Experiments were conducted using two biofilter units filled with quartz sand as filter media. A set of experiments were performed to evaluate the effect of hydraulic retention time on biofilter performance in removing water contaminants. The kinetics of organic matter removal were also determined to describe the performance of the biofilter. The results show that biofiltration can significantly remove river water pollutants. Removal efficiency depends on the applied hydraulic retention time. At a hydraulic retention time of two hours, removal efficiencies of total organics, ammonium and total suspended solids were up to 78%, 82%, and 91%, respectively. A model for designing quartz sand biofiltration has been developed from the experimental data.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.E3
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• pp.153-163
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• 2002

A laboratory- scale dual-column biofilter system was used to study the biofiltration of dimethyl disulfide (DMDS). The gas flow rate and DMDS concentration to the biofilter were varied to study their effect on the remov-al of dimethyl disulfide. Operating parameters such as pH, temperature, and water content were monitored during the biofilter operation and necessary precautions were taken to keep these parameters within the acceptable limits. It was observed that the removal efficiency of DMDS was optimal at neutral pH values. After five month op-eration, the neutralization of the filter beds with sodium carbonate became necessary for the optimum operation of the biofilters. The microbial population already present in the compost mixtures was found to be adequate in treat-ing DMDS. The compost mixtures were found to be similar in terms of biofiltration efficiency of DMDS. However, pressure drops observed in the first column compost mixture (compost/ peat mulch) was extremely high, making this compost economically not feasible. The second mixture (compost/bark) provided pressure drops within accept-able limits. A minimum residence time of 30 seconds at the optimal operating conditions appeared to be adequate for achieving high removal efficiencies (>90%).

• 한국생물공학회:학술대회논문집
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• 2004.07a
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• pp.85-106
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• 2004

Styrene as volatile organic compounds(VOC) has come under strict regulatory control as they cause serious health and environmental problems. Biofiltration offers a number of economical and environmental advantages over conventional technologies, such as incineration, catalytic adsorption, and chemical scrubbing. In this presentation, recent progresses on the development of lab-scale biofilter for the treatment of gas-phase styrene are reviewed, The potentials of commercialization of biofilter systems are also discussed.

• Journal of Environmental Science International
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• v.15 no.6
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• pp.513-525
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• 2006

In recent decades, biofiltration has been widely accepted for the treatment of contaminated air stream containing low concentration of odorous compounds or volatile organic compounds (VOCs). In this study, conventional biofilters packed with flexible synthetic polyurethane (PU) foam carriers were operated to remove toluene from a contaminated air stream. PU foams containing various amounts of pulverized activated carbon (PAC) were synthesized for the biofilter media and tested for toluene removal. Four biofilter columns were operated for 60 days to remove gaseous toluene from a contaminated air stream. During the biofiltration experiment, inlet toluene concentration was in the range of 0-150 ppm and EBRT (i.e., empty bed residence time) was kept at 26-42 seconds. Pressure drop of the biofilter bed was less than 3 mm $H_2O/m$ filter bed. The maximum removal capacity of toluene in the biofilters packed with PU-PAC foam was in the order of column II (PAC=7.08%) > column III (PAC=8.97%) > column I (PAC=4.95%) > column IV (PAC=13.52%), while the complete removal capacity was in the order of column II > column I > column III > column IV. The better biofiltration performance in column II was attributed to higher porosity providing favorable conditions for microbial growth. The results of biodegradation kinetic analysis showed that PU-PAC foam with 7.08% of PAC content had higher maximum removal rate ($V_m$=14.99 g toluene/kg dry material/day) than the other PU-PAC foams. In overall, the performance of biofiltration might be affected by the structure and physicochemical properties of PU foam induced by PAC content.