• Carbon letters
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• 제3권4호
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• pp.187-191
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• 2002

In the present research, we prepared the activated carbon (AC) sorbents to remove gas-phase mercury. The mercury adsorption of virgin AC, chemically treated AC and fly ash was performed. Sulfur impregnated and sulfuric acid impregnated ACs were used as the chemically treated ACs. A simulated flue gas was made of SOx, NOx and mercury vapor in nitrogen balance. A reduced mercury adsorption capacity was obtained with the simulated gas as compared with that containing only mercury vapor in nitrogen. With the simulated gas, the sulfuric acid treated AC showed the highest performance, but it might have the problem of corrosion due to the emission of sulfuric acid. It was also found that the high sulfur impregnated AC also released a portion of sulfur at $140^{\circ}C$. Thus, it was concluded that the low sulfur impregnated AC was suitable for the treatment of flue gas in terms of stability and efficiency.

• 에너지공학
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• 제25권1호
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• pp.171-176
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• 2016

신흥 선진국들의 급격한 에너지소비 증가와 청정에너지 자원의 고갈로 인해 현재 개발 단가가 높은 미개발 오일 가스 저유지를 개발하고 있는데 이들 오일 가스전은 다량의 부식성 황 화합물($H_2S$)과 $CO_2$, 부탄, 메르캅탄(mercaptan)등을 함유하고 있다. $H_2S$ 가스는 인체에 치명적인 영향을 미치는 독성가스 중 하나이며, $CO_2$ 가스는 지구 온난화에 영향을 가장 많이 미치고 있는 온실가스 중 하나이다. 이러한 유전과 가스전 개발에는 특수 장비와 작업을 안전하게 할 수 있는 고도의 기술력이 필수적이기 때문에 선진국들은 $H_2S/CO_2$ 가스를 함유하고 있는 사워가스/산성가스 처리와 제거기술을 개발하고 있다. 가스전의 가스(raw gas) 처리기술은 저유지의 특성 및 가스에 함유된 $H_2S$의 구성요소들에 의해 좌우된다. 여기서는 많은 양의 황산을 함유하고 있는 오일과 가스에 대한 효율적인 처리 및 처리 비용 그리고 분리장치 기술 및 생산시스템에 관한 문제에 대해서 서술하고자 한다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권6호
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• pp.37-45
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• 2010

Surfactant-enhanced ozone sparging (SEOS), an advanced version of SEAS (surfactant-enhance air sparging) was introduced in this study for the first time for removal of non-volatile contaminant from aquifer. The advantages of implementing SEAS, enhanced air saturation and expanded zone of sparging influence, are combined with the oxidative potential of ozone gas. Experiments conducted in this study were tow fold; 1-dimensional column experiments for the changes in the gas saturation and contaminant removal during sparging, and 2-dimensional box model experiment for the changes in the size of zone of influence and contaminant removal. An anionic surfactant (SDBS, sodium dodecylbenzene sulfonate) was used to control surface tension of water. Fluorescein sodium salt was used as a representative of watersoluble contaminants, for its fluorescence which is easy to detect when it disappears due to oxidative degradation. Three different gases (air, high-concentration ozone gas, and low-concentration ozone gas) were used for the sparging of 1-D column experiment, while two gases (air and low-concentration ozone gas) were used for 2-D box model experiment. When SEOS was performed for the column and box model, the air saturation and the zone of influence were improved significantly compared to air sparging without surface tension suppression, resulted in effective removal of the contaminant. Based on the experiments observations conducted in this study, SEOS was found to maintain the advantages of SEAS with further capability of oxidative degradation of non-volatile contaminants.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권5호
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• pp.316-322
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• 2002

A newly isolated heterotrophic marine bacterium, Vibrio alginolyticus, was used to remove a high load of ammonia gas under non-sterile condition. The cells were inoculated onto an inorganic packing material in a fixed-bed reactor (biofilter), and a high load of ammonia, in the range of ammonia gas concentration of 170 ppm to 880 ppm, was introduced continuously. Sucrose solution and 3% NaCl was supplied intermittently to supplement the carbon source and water to the biofilter. The average percentage of gas removed exceeded 85% for 107-day operation. The maximum removal capacity and the complete removal capacity were$19\;g-N\;kg^{-1}$ dry packing material $day^{-1}$ and $16\;g-N\;kg^{-1}$ dry packing material $day^{-1}$, respectively, which were about three times greater than those obtained in nitrifying sludge inoculated onto the same packing material. On day 82, the enhanced pressure drop was restored to the normal one by NaOH treatment, and efficient removal characteristics were later observed. During this operation, the non-sterile condition had no significantly adverse effect on the removability of ammonia by V. alginolyticus.

• Journal of Korean Society for Atmospheric Environment
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• 제14권E호
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• pp.1-7
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• 1998

This paper presents an experimental study for understanding the indoor air quality in a room. A model room, which had a ceiling-mounted supply and a sidewall-mounted exhaust, was used to examine the effect of air exchange rate (AER) and contaminant source location (CSL) as a function of the elapsed time. A tracer gas method, using carbon monoxide tracer, gas analyzers, and a data acquisition system, was applied to study the ventilation air distribution and the tracer removal efficiency, so-called pollutant removal efficiency, in the model room. The experiment was composed of two parts; firstly the AER was varied to examine its effect on the ventilation air distribution and the ventilation effectiveness and secondly both AER and CSL were considered to determine their effect on the pollutant removal efficiency. It was found that the ventilation effectiveness in the model was proportional to AER but not linearly. It was also found that changing the CSL can improve the pollutant removal efficiency. In some cases, the efficiency improvement by increasing AER was achieved by simply changing CSL.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2003년도 Challenges and Achievements in Environmental Health
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• pp.152-156
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• 2003

Air pollution problems due to the emission of pollutants from the various industrial facilities become serious issues and lots of air pollution control processes have been developed. To remove the SO$_2$ and NOx emitted from the solid waste incinerator and coal fired power plants, we studied the Ca-based sorbent which was prepared by waste clam and limestone. The objectives of this study were to develop a clam-based sorbent for removal of SO$_2$ and NOx, and to investigate the physicochemical properties of the waste clam sorbent. In order to determine acid gas removal capacity of sorbent, the batch study on SO$_2$ and NOx removal was performed with the Ca-based sorbent in the fixed bed reactor. Results of the research revealed that clam-based sorbent can be used as the iron-manufacturing industry and chemical adsorbents for the removal of acid gases because the lime content of the waste calm was more than 53.92%. From physicochemical analysis and gas reaction experiments, it could be concluded that clam is good sorbent for the removal of SO$_2$ and NOx in waste incinerator and flue gas desulfurization processes.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.488-492
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• 2007

In this study, experiment was done to verify the relationship between sprayed water's pH and gas removal efficiency of the Air Washer system. The experiment was done with sprayed water's pH in between pH 4.7 to 7.7, and Ion Chromatography analysis was used to identify the system's gas removal efficiency. As a result, $NH_3$ is removal efficiency decreased under 50% above pH 7, and $SO_X$ and $NO_X$ removal efficiency decreased under pH 6. Through this research, the optimum pH operating condition of the Air Washer System was conformed to be in range between pH6 to pH6.5.

• 한국대기환경학회지
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• 제24권4호
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• pp.415-422
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• 2008

This study was carried out to investigate the effect of operating and design conditions of gas dispersion type of absorber on $SO_2$ removal efficiency. pH difference between upper and lower part of gas dispersing plate of absorber was 0.2, which was relatively low. This was supposed that recirculation capacity of absorbing liquid between froth zone and reaction zone of absorber be increased by oxidation air injection through liquid riser which acted as liquid pump. Test results showed that $SO_2$ removal efficiency was more sensitive than absorber ${\Delta}P$. High $SO_2$ removal even at lower pH resulted from very low concentration of $HSO_3^-$ ion in absorbing liquid because of direct supply of dissolved oxygen into froth zone. 96% of $SO_2$ removal efficiency was obtained under the condition of absorber pH 5.2, flue gas flow rate of $1,530\;Nm^3/hr$, inlet $SO_2$ concentration of 800 ppm, absorber ${\Delta}P$ of 250mmAq. The following equation by a multiple linear regression was obtained to describe the relationship between $SO_2$ removal and operating variables. $$f=1-{\exp}(-1.3939+1.060pH+0.0139{\Delta}P-0.00267G-0.000064SO_2Conc.),\;R^2=0.9719$$

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1780-1782
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• 2001

In this experiment, an attempt to use the sludge pellets as catalyst for NO removal from simulated gas is experimentally investigated by using $BaTiO_3$-sludge packed-bed reactor of plate-plate geometry. An experimental investigation has been conducted for NO concentration of 50[ppm] balanced with air, a gas flow rate of 5[1/min]. $BaTiO_3$ pellets are filled at upstream of reactor for corona discharge and sludge pellets are put at downstream of reactor for catalystic effect. The volume rate of sludge pellets to $BaTiO_3$ pellets is 50[%] and AC voltage to dischare the gases was supplied. In the result, when sludge pellets is seperated to $BaTiO_3$ by other reactor and AC voltage is supplied to $BaTiO_3$ and sludge pellets NO, $NO_2$ removal rate is higher. When gas temperature increase from room temperature to 100[$^{\circ}C$], NO removal is decreased while $NO_2$ concentration is independent on gas temperature. This result suggest that the removal mechanism of active oxyzen species and $NO_2$ in sludge is not absorption, but chemical reaction. Temperature of heating treatment is on sludge pellets increased, $NO_x$ removal rate is decrease. It is thought that organic compound is removed by heating treatment.

• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.737-743
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• 1999

A conventional thermophilic anaerobic digester was converted into a thermophilic high-rate hybrid anaerobic reactor (THAR) for treating distillery wastewater. The THAR has been operating successfully since May 1995 at a loading rate of 5.45 to $11.52{\;}kg/\textrm{m}^3/d$ (maximum of 15.02). The THAR has demonstrated a soluble Chemical Oxygen Demand (sCOD) removal efficiency of 85 to 91% and a total COD (tCOD) removal efficiency of as much as 72 to 84%. Product gas had a methane content of 59 to 68%. The tCOD removal rates were 4.31 to 5.43, 6.26 to 6.89, and 9.03 to $9.78kg{\;}tCOD/\textrm{m}^3/d$ for tapioca, com, and naked-barley wastewater, respectively. The sCOD removal rates ranged from 3.75 to 4.79,3.28 to 4.89, and 5.57 to 6.21kg $sCOD/\textrm{m}^3/d$ for tapioca, com, and naked-barley wastewater, respectively. There were unknown substances in a naked-barley distillery wastewater that were identified as being toxic for microorganisms. However, the THAR treated naked-barley wastewater continuously for 26 days, operating at an average tCOD loading of $11.08{\;}kg/\textrm{m}^3/d$without any signs of deterioration in either COD removal efficiency or gas production rate. During this period, the average removal efficiencies of tCOD and sCOD were 84% and 91%, respectively, and the gas production rate averaged 6.61 to $7.57{\;}\textrm{m}^3/\textrm{m}^3$ reactor/d which produced 0.57 to $0.69{\;}\textrm{m}^3{\;}biogas/kg{\;}tCOD_{rem}$. From tapioca and com wastewater, the reactor showed an average gas production rate of 3.18 to 3.46 and 4.91 to $5.22{\;}\textrm{m}^3/\textrm{m}^3$ reactor/d which produced 0.53 to 0.69 and 0.62 to $0.71{\;}\textrm{m}^3/kg{\;}tCOD_{rem}$, respectively.