• Journal of Environmental Science International
• /
• v.11 no.6
• /
• pp.605-610
• /
• 2002

The absorption of benzene in nonpolar solution was studied in a laboratory-scale of bubble column varying of gas flow rates and gas-to-liquid ratios. A bubble column had a 0.8∼l$\times$10$\^$-3/ m$^3$ total volume (height 1500 mm, diameter 50 mm). Solution analysis was performed by GC-FID and GC-MSD. The objectives of this research were to select the best absorption fluid and to evaluate the mass transfer characteristics under specific conditions of each absorption. The results of this research were follow as: First, the heat transfer fluid is more efficient than the other nonpolar solution in removing VOC. Second, The benzene removal efficiency improved according to an increasing rate of gas flow. Also, volumetric mass transfer rate of column can be enhanced by increasing gas flow rate. Finally, the relation of gas flow rates, liquid amount, and volumetric mass transfer coefficient was obtained as follows. K$\_$y/a: 0.5906(V$\_$g//L)$\^$0.7611/ The following correlation of mass transfer coefficient and efficiency was proposed. v= 0.06078 K$\_$y/a$\^$0.2444/.

• Journal of Environmental Science International
• /
• v.15 no.9
• /
• pp.855-864
• /
• 2006

This study introduces a method to eliminate formaldehyde and benzene, toluene from indoor air by means of a photocatalytic oxidation reaction. In the method introduced, for the good performance of the reaction, the effect and interactions of the $TiO_2$ catalyst and ultraviolet in photocatalytic degradation on the reaction area, dosages of catalysts, humidity and light should be precisely examined and controled. Experiments has been carried out under various intensities of UV light and initial concentrations of formaldehyde, benzene and toluene to investigate the removal efficiency of the pollutants. Reactors in the experiments consist of an annular type Pyrex glass flow reactor and an 11W germicidal lamp. Results of the experiments showed reduction of formaldehyde, benzene and toluene in ultraviolet $/TiO_2/$ activated carbon processes (photooxidation-photocatalytic oxidation-adsorption processes), from 98% to 90%, from 98% to 93% and from 99% to 97% respectively. Form the results we can get a conclusion that a ultraviolet/Tio2/activated carbon system used in the method introduced is a powerful one for th treatment of formaldehyde, benzene and toluene of indoor spaces.

• Journal of the Korean Society of Tobacco Science
• /
• v.14 no.1
• /
• pp.87-93
• /
• 1992

The adsorption efficiency of some adsorbents for the organic solvents and gas phase of smoke was investigated. 1. Specific surface area of activated carbon increased to 1900 mfg with increased activation time. 2. Adsorption efficiency of benzene and acetone increased with increasing total surface area. Adsorption capacity for gas phase such as hydrogen cyanide, aldehyde was proportional to the micro pore surface area under 20A. 3. The removal efficiency of particulate matter of smoke was higher with the adsorbents of relatively higher pore size compared to that of micro pore.

• Journal of Korean Society of Water and Wastewater
• /
• v.13 no.3
• /
• pp.91-100
• /
• 1999

Treatment conditions of DAF(Dissolved Air Flotation) and removal rates of VOCs(Volatile Organic Compounds) in mixed water of H raw water and VOCs were investigated. The used VOCs were benzene, toluene, ethylbenzene, and xylene in aromatic compounds and iso propyl mereaptan, n-butyl mereaptan, dimethyl disulfide, and iso butyl mercaptan in odors. The related parameters include water type, treatment method, clay concentration, pH condition, flocculation time, flotation time, per-cent recycle, water temperature, pressure. The removal rates of VOCs were different on treatment process and water condition. Treatment time was longer, removal rates of VOCs was higher. Water temperature was more important than pressure in DAF parameters. Molecular weight was related with removal rate in several kinds of VOCs were decraesed by competition of each component in II raw water. When algac blooming D water was treated by DAF, TCOD(Total chemical Oxygen Demand) and chorophyll a was removed over 96%.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2006.04a
• /
• pp.127-131
• /
• 2006

• Journal of Korean Society of Environmental Engineers
• /
• v.29 no.7
• /
• pp.755-760
• /
• 2007

• KSBB Journal
• /
• v.16 no.3
• /
• pp.281-285
• /
• 2001

Biofiltration of volatile organic compounds (VOCs) was performed for 80 days in a biofilter packed with peat. The empty bed residence time was 3.2 min. for a gas mixture of isoprene, dimethyl sulfide, chloroform. benzene, trichlorethylene, toluene, m0xylene, o-xylene and styrene. After 34 days of acclimatization the removal efficiency for a 83 g/㎥ gas input was 93% at $25^{circ}C$ and 73% at $45^{circ}C$, respectively. The maximum cell density at $25^{circ}C$ was 1.12$\times$10(sup)8 cells/g. Removal efficiencies of m-xylene and toluene (91%) were better than that of benzene (86%). The first quarter of the packed column removed 60% of the incoming VOCs.

• Fire Science and Engineering
• /
• v.29 no.6
• /
• pp.65-70
• /
• 2015

This research examines the removal efficiency of benzene, toluene, xylene (BTX) and total volatile organic compounds (TVOCs) by flowing VOCs, which are generated at a petrochemical complex in the Ulsan area, in a sliding arc plasma (SAP) reactor. The SAP reactor process is composed of 5 steps and the analysis was conducted using a BTX detector and TVOC measuring instrument. The removal efficiency of BTX was better at high concentration than at low concentration and the emitted TVOC concentration increased in later steps of the reactor. In addition, the removal efficiency improved, as the flow velocity increased. The maximum permissible concentration of TVOCs in the first step was about 481 ppm and showed over 94.83% efficiency when it was operated in the 2nd step at concentrations beyond 481 ppm. Therefore, there are many factors for improving the removal efficiency of SAP reactors at low concentration and measures should be prepared according to the application method for the various types of industrial reactors.

• Proceedings of the IEEK Conference
• /
• 2001.10a
• /
• pp.117-121
• /
• 2001

The present study has been conflicted to verify the applicability of tire powder and food waste compost as biofilter materials to degrade volatile organic compounds. Batch and column tests were performed to determine the optimum ratio of tire powder to compost and the appropriate mixing type of two materials for removal of the selected VOCs, i.e., benzene, ethylbenzene, PCE, and TCE. According to batch tests, tire powder and compost mixture had faster removal rate than the compost. The biofilter column filled with tire powder and compost showed better VOC removal efficiency than that filled with only tire powder. In this study, the best removal rate was observed in the sandwich type column test of which the tire : compost weight ratio was 1:2

• Journal of Korean Society of Water and Wastewater
• /
• v.25 no.5
• /
• pp.741-750
• /
• 2011

A pilot-scale biofilter was constructed to discover degradation characteristics of the complex odor discharged from Ansan wastewater treatment plant. Candida tropicalis for volatile organic compounds, sulfur oxidizing bacteria(SOB) for hydrogen sulfide, and bacteria extracted from feces soil were immobilized on a polymer gel media. According to this study, the EBCT was varied from 36 sec to 18 sec. Toluene was removed as 80% along the variations, but it was recovered as 100% within 1 week. All benzene and xylene were removed during the operation while the efficiency of hydrogen sulfur was temporary decreased at 18 sec of EBCT, thereafter it was recovered to 100% within a week. The maximum elimination capacities of the benzene, toluene, xylene, and hydrogen sulfur were 6.6 g/$m^{3}$/hr, 31.7 g/$m^{3}$/hr, 7.8 g/$m^{3}$/hr, and 133.6 g/$m^{3}$/hr, respectively. There were merits on removal both organic and inorganic complex odor using the pilot-scale biofilter embedded with microorganisms immobilized on polymer gel media.