• Environmental engineer
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• v.24 s.254
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• pp.54-59
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• 2007

본 기술은 각종 산업시설과 환경 기초 시설로부터 대기중으로 배출되는 악취 및 휘발성 유기화합물(Volatile Organic Chemicals; VOC)을 미생물의 분해 작용을 활용하여 제거하는 장치로 오염 물질의 분해과정에서 미생물의 과다생장에 의한 악취 및 휘발성 유기화합물 제거장치의 막힘현상을 미생물 고정화 담체의 교반과 살수과정을 통해 담체표면의 생물막을 효과적으로 제거하는 방법을 이용하여 오염 가스속에 함유되어 있는 악취 및 휘발성 유기화합물을 효율적으로 제거할 수 있는 기술이다. 특히, 미생물 담체의 교반 장치는 미생물 고정화 담체를 교반시켜 생물막을 탈리 시킴으로써 미생물의 생장에 의한 막힘 현상과 이로 인한 압력 손실 증가와 악취 및 휘발성 유기화합물의 제거성능의 저하를 근본적으로 해결할 수 있다.

• Journal of the Korean GEO-environmental Society
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• v.8 no.4
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• pp.41-45
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• 2007

It is very important that selection of packing media with large surface area, high limited back pressure in biofilter. The object of this study is the isolation of sulfur-oxidizing bacteria and the removal of hydrogen sulfide in biofilter by media. This investigation led to the following results: 1) we isolated Thiobacillus sp. IW. at an abandoned coal mine in Hwasun, Jeonnam Province. 2) The inorganic media showed better results than the organic media from experiments looking at removal characteristics and changes in pressure drop using various media. 3) Among the inorganic media, fibril and PU media showed best performance.

• Proceedings of the Membrane Society of Korea Conference
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• 1993.04a
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• pp.34-34
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• 1993

세라믹 분리막은 유기질 막에 비하여 열적, 기계적 및 화학적으로 안정하기 때문에 기존의 유기질 막을 사용하기 어려운 작업 조건 하에서도 응용의 잠재성을 가지고 있다. 본 실험은 disk형태의 다공성 $Al_2O_3$ 담체위에 CVD 법과 Evaporation Oxidation 법에 의해 $Al_2O_3$를 코팅하여 세라믹 분리막을 제조하였다. CVD법에 의한 제조는 Al-isopropoxide를 350$\circ$C에서 담체위에 증착시켜 제조하였으며, Evaporation-Oxidation 법에 의한 제조는 Al을 담체위에 evaporation 시킨 후 dry oxidation 시켜서 제조하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.3
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• pp.255-260
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• 2005

PAHs are aromatic hydrocarbon compunds with two or more benzene rings. Because they are mostly toxic to human life, they need to be converted to non-toxic compunds or to be degraded completely. This work aims to degrade PAHs (phenanthrene and pyrene) using Bacillus bacteria covered on cork or sawdust. The results show that media effect on phenanthrene was negligible whereas biodegradation ability of sawdust carrying the bacteria was better than that of biofilm-covered cork when pyrene was tested. PAH removal was also affected by soil moisture content with $45\~55\%$ of the optimal content.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.8
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• pp.603-610
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• 2009

This research was performed to improve removal efficiency of toluene and methyl ethyl ketone (MEK) using Candida tropicalis, one of the yeast species. An airlift loop bioreactor (ALB) was employed to enhance the capability of mass transfer for toluene and MEK from the gas phase to the liquid, microbial phase. Polymer gel media made from PAC, alginate and PEG was applied for the effective immobilization of the yeast strain on the polymer gel media. The experimental results indicated that the mass transfer coefficient of toluene without polymer gel media was 1.29 $min^{-1}$ at a gas retention time of 15 sec, whereas the KLa value for toluene was increased to 4.07 $min^{-1}$ by adding the media, confirming the enhanced mass transfer of volatile organic compounds between the gas and liquid phases. The removal efficiency of toluene and MEK by using yeast-immobilized polymer gel media in the ALB was greater than 80% at different pollutant loading rates (5, 10, 19 and 37 g/$m^3$/hr for toluene, 4.5, 8.9, 17.8 and 35.1 g/$m^3$/hr for MEK). In addition, an elimination capacity test conducted by changing inlet loading rates stepwise demonstrated that maximum elimination capacities for toluene and MEK were 70.4 and 56.4 g/$m^3$/hr, respectively.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.193-194
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• 2002

휘발성 유기화합물(VOCs)은 환경에 광범위하게 분포되어 있으며 특히 벤젠(benzene)은 발암물질로 규제가 강화되고 있다 또한 높은 증기압과 헨리상수를 가지고 있으므로 환경 중 이동이 용이하므로 대기, 수중, 토양 모두에 심각한 오염물질이 되고 있다. 이런 유기화합물 처리에 높은 효율을 나타내는 것이 자외선을 이용한 광분해(UV/Photodegradation)로 TiO$_2$를 촉매로 이용하는 것이다(Blystone et al., 1991). (중략)

• Journal of Korean Society of Environmental Engineers
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• v.27 no.6
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• pp.573-580
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• 2005

This study was to investigate the removal characteristics of toluene in a gas stream by using a biotrickling filter packed with zeolite-contained polyethylene media. The specific surface area and the void fraction of the media were $500\;m^2/m^3$ and 82%. The surface roughness of the media was higher than that of pure polyethylene media. The toluene removal efficiency decreased with increasing the inlet toluene concentration and gas flow rate. The maximum elimination capacity of toluene in the biotrickling filter was $64\;g/m^3{\cdot}hr$. During 200 days operation, toluene removal efficiency was maintained from 90% to 98% until 167 days, hereafter, it was rapidly reduced with a rise in pressure drop due to an excess proliferation of biomass on the media. Pressure drop and removal capability of the biotrickling filter was fully recovered after backwashing.

• Journal of Soil and Groundwater Environment
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• v.10 no.1
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• pp.35-42
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• 2005

This research was investigated the applicability of the biofiltration technology for the removal of volatile organic carbons (VOCs) produced from the bioremediation of oil contaminated soil. Diesel was used as surrogate for oil and, two types of biofilter systems made of ceramic and polymer media were compared for the removal efficiencies of diesel VOCs at different inlet concentrations and space velocity (SV) conditions. During the first 30-d operation, the removal efficiencies of the biofilter packed with polymer and the biofilter packed with ceramic were investigated at constant SV of $153\;h^{-1}$ When inlet concentrations of diesel VOCs were below 10 ppmv, the average removal efficiencies of the polymer biofilter and the ceramic biofilter were average $67\%\;and\;75\%$, respectively. When the inlet concentration increased to 30 ppmv, the VOC removal efficiency in the polymer biofilter was $80\%$, while the average removal efficiency in the ceramic biofilter was $60\%. Effect of the inlet concentration and SV on the removal efficiency of total diesel VOCs was investigated. As SV increased from $153\;h^{-1}$ to $204\;h^{-1}$ and $306\;h^{-1}$, the removal efficiency of total diesel VOCs was decreased gradually. The average removal efficiency of the biofilter packed with polymer carrier was decreased from $82\%\;to\;80\%\;and\;77\%$. The biofilter packed with polymer carrier showed that the removal efficiency of benzene and toluene were maintained within the range of $81\%\~86\%$. In contrast, for the biofilter packed with ceramic carrier, when SV increased from $153\;h^{-1}$ to $204\;h^{-1}$ and $306\;h^{-1}$, the removal efficiency of benzene decreased from $87\%\;to79\%\;and\;74\% . respectively. The removal efficiency of toluene decreased from $80\%\;to\;77\%\;and\;76\%$ at SV of $153\;h^{-1},\;204\;h^{-1}\;and\;306\;h^{-1}$, and $306\;h^{-1}$, respectively.

• KSBB Journal
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• v.15 no.4
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• pp.352-358
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• 2000

Preparation for the simplified separation of chitosandoligosaccharides from enzymatic hydrolysate was investigated. Two different types of chitosan beads as substrate were prepared as organic-based bead by W/O emulsion method and water-based bead by alkaline treatement. The average size of organic-based bead was $200{\mu}m$, and that of water based beads were $4000{\mu}m$, $100{\mu}m$, $30{\mu}m$, in diameter respectively. Enzyme stability was maintained over 80% at PH 6 after 24 hours. The optimal condition for the production of chitosanoligosaccharides was at pH 6.0, $50^{\circ}C$ and 40U (200U/g-chitosan) According to final oligosaccharide concentration water-based bed showed the similar result with that of organic-based bead even through it had smaller surface area attacked by chitosanse than that of organic-based bead. It is probable that the structure of water-based chitosan bead was looser than that of organic-based bead so enzyme penetrated easily into the bead structure. For the oligosaccharide production versus surface area the different size of water-based beads was investigated, Maxiaml production yield was observed in the $30{\mu}m$ beads. Consequently the water-based chitosan bead was better than the organic-based bead in this reaction system.

• Economic and Environmental Geology
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• v.41 no.1
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• pp.57-62
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• 2008

The application of constructed subsurface-flow wetlands for treatment of wastewater from abandoned mines is being increased. Crushed limestone, oak chips, and mushroom composites are often employed in a bulk form, as the substrates in the bed media. Efficiency of the subsurface-flow treatment system drops with time as the hydraulic conductivity of the wetland soil decreases significantly, presumably due to chemical reactions with the wastewater. The purpose of this study is to investigate the applicability of immobilized beads carrying sulfate reducing bacteria for acid mine drainage treatment system. The ingredients of immobilized beads are organic materials such as mushroom composite and oak chips, limestone powder for a pH buffer, mixed with a modified Coleville Synthetic Brine. It was found that immobilized beads are more efficient than the bulk form for pH recovery, sulfate and heavy metal removal.