• 환경위생공학
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• 제18권2호
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• pp.87-93
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• 2003

This study carried out to recommend adaptable technologies and countermeasures for performance improvement of Wet Scrubber(WS) in industrial waste incinerator. When not using the Activated Carbon(AC), the removal efficiency of dust and HCl is 73%, 92%. And particulate phase and gaseous phase dioxins removal efficiency was evaluated up to 31% and 12%. In this case, dioxins enrichment was not revealed in WS. When using the AC mixing with scrubbing water, the case of 1,000ppm, removal efficiency of particulate phase dioxins was about 51%, and gaseous phase dioxins was about 96%. The case of 2,000ppm, removal efficiency of particulate phase dioxins was about 55%, and gaseous phase dioxins was about 97%. And the case of 3,500ppm, the removal efficiency of particulate phase dioxins was about 35%, and gaseous phase dioxins was about 96% respectively. By this study, using the AC was more useful to remove the gaseous phase dioxins, and needed to use proper concentration of the AC, that in case of 3,500ppm, the particulate phase dioxins removal efficiency was more lower than other cases.

• Korean Chemical Engineering Research
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• 제47권5호
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• pp.580-586
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• 2009

본 연구에서는 2 MWe 규모 순환유동층 발전소에서 중국산 유연탄과 북한산 무연탄의 혼합연소특성을 실험적으로 고찰하였다. 중국유연탄과 호주유연탄을 과잉공기량과 층온도 등을 변수로 실험한 결과, 연소효율은 석탄입자의 입도와 석탄중의 휘발분의 영향을 받으며, 이 때 미연탄소분은 Fly ash 5~7%, 바닥회 0.3% 수준으로 중국 유연탄의 연소효율은 99.5% 이상을 보였다. 북한산 무연탄과 유연탄의 혼소시 혼합비 20%에서 무연탄의 평균입도가 작아 연소실에서 비산되는 입자로 인해 연소효율은 5% 이상 저하되었다, 그러나 $SO_2$와 NOx의 배출농도는 크게 변화하지 않았다. 배출되는 대기오염물질의 농도는 $NO_x$ 200~250 ppm($O_2$ 6%), $SO_2$ 100~320 ppm($O_2$ 6%)이었다. SCR 공정에서 2~13 l/min 범위의 $NH_3$ 공급으로 30~65%의 $NO_x$가 저감되었다. Limestone을 이용한 노내탈황에서 약 Ca/S 몰비 6.5를 공급했을 때 $SO_2$가 75% 제거되었고, $Mg(OH)_2$를 흡수제로 하는 FGD를 운전했을 때 pH 5.0 이상에서 100% 탈황효과를 보였다.

• Nuclear Engineering and Technology
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• 제54권9호
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• pp.3310-3316
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• 2022

Owing to the rising concerns about the safety of nuclear power plants (NPP), it is essential to study the venturi scrubber in detail, which is a key component of the filtered containment venting system (FCVS). FCVS alleviates the pressurein containment byfiltering and venting out the contaminated air. Themain objective of this research was to perform a CFD investigation of different configurations of a circular, non-submerged, self-priming venturi scrubber to estimate and improve the performance in the removal of elemental iodine from the air. For benchmarking, a mass transfer model which is based on two-film theory was selected and validated by experimental data where an alkaline solution was considered as the scrubbing solution. This mass transfer model was modified and implemented on a unique formation of two self-priming venturi scrubbers in series. Euler-Euler method was used for two-phase modeling and the realizable K-ε model was used for capturing the turbulence. The obtained results showed a remarkable improvement in the removal of radioactive iodine from the air using a series combination of venturi scrubbers. The removal efficiency was improved at every single data point.

• 한국환경과학회지
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• 제23권11호
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• pp.1953-1961
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• 2014

Increasing public concerns over odors and air regulations necessitates the remediation of a wide range of odor substances for industrial and indoor purpose. Currently, the wet scrubbing technique by neutralization using oils is being used to treat odor substances such as Ammonia($NH_3$), Methyl Mercaptan($CH_3SH$), Hydrogen Sulfide($H_2S$), Methylamine($CH_3NH_2$), Acetaldehyde($CH_3CHO$). The chemical analysis is performed to analyze the composition of an Arctium Lappa Root extract by VOC analyzer(Phocheck 5000Ex, ION SCIENCE co.) The objectives of the this study are to clarify the possibility of the neutralization of odors sprayed in the fixed bed and determine the removal efficiencies for different input odor concentrations. It is found that Ammonia($NH_3$), Methyl Mercaptan($CH_3SH$), Hydrogen Sulfide($H_2S$), Methylamine($CH_3NH_2$), Acetaldehyde($CH_3CHO$) are significantly removed and their removal efficiencies are higher than 98%. The kitchen detergent with Arctium Lappa Root extract showed excellent removal efficiencies of odor substances and high possibility for the development of kitchen detergent with odor removal.

• Journal of Advanced Marine Engineering and Technology
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• 제30권1호
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• pp.81-87
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• 2006

In marine air pollution control, SCR (Selective Catalytic Reduction) is reconized as the most effect method to control NOx, but on the other hand. seawater scrubber applying the basic characteristic that is naturally alkaline (pH typically around 8.1) is viewed as an economical SOx removal system at present. Especially, seawater scrubber would not be necessary to follow any of the various land based flue gas desulfurization methods. i.e. wet, dry or alkali scrubbing. However, these methods are not readily adaptable to marine conditions due to the quantifies of consumables required i.e. lime or limestone, the means of operation and the commercial availability. This research is undertaken to develop a new method as the main target of eliminating all exhaust emissions, particularly vessel, because of easy access to seawater and apt to apply a wet scrubber system. First, using the acidic seawater by seawater electrolysis, nitric monoxide(NO) is adequately oxidized to nitric dioxide $(NO_2)$by ClOx-in the acidic seawater, the electrolyzed alkaline seawater by electrolysis which contains mainly NaOH together with alkali metal ions $(i.e\;Na^{+}\;K^{+},\;Mg_{2}\;^{+},\;Ca_{2}\;^{+})$, is used as the absorption medium of NOx, the SOx are absorbed by relatively high solubility compared to other components of exhaust pollutants. The results found that the NOx and SOx removals could be achieved nearly Perfect.

• 한국막학회:학술대회논문집
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• 한국막학회 2004년도 Workshop
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• pp.57-68
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• 2004

A demonstrative operation of a membrane system with its caparity of 3,600m$^3$/d was carried out using reservoir water as raw water for the application of membrane filtration system to drinking water treatment. The operation was undertaken at a constant flux of 0.9 m$^3$/m$^2$/d for three months. Backwashing with NaClO of 3 ppm was allowed for 30 seconds every 20 minutes of filtration. Physical cleaning was introduced after 69 times of filtration/backwashing cycle with air-scrubbing and backwashing for 1 minute, and flushing for 2 minutes. In this study, water treatment performance was investigated compared with the existing rapid sand filtration process. The membrane system was operated with no significant problems during the test period. Higher water quality was obtained in the membrane filtration than in the rapid sand filtration in terms of particulate matters such as turbidity and microbes. Although the finished water of the membrane filtration contained slightly higher concentration in dissolved matters than that of the conventional one, it met the drinking water standard. The demonstrative operation showed that membrane filtration has a reliability in drinking water treatment. Researches should be needed on cost analysis through long-term operation and optimization of operation condition for further application.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.486-492
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• 2022

Nitrogen oxides (NO_x; NO and NO₂) are major air pollutants and can cause harmful effects on the human body. Electron Beam Flue Gas Treatment (EBFGT) is a technology that generates electrons with an energy of 0.5-1 MeV using electron accelerators and effectively processes exhaust gases. In this study, NO_x was removed using an electron beam accelerator with spraying additives (NaOH and NH₄OH). NO and NO₂ were 100% and more than 94% removed, respectively, at an electron beam absorbed dose of 20 kGy and an additive concentration of 0.02 M (mol/L). In most cases, NO_x was removed better with lower initial NOx concentrations and higher electron beam absorbed doses. As the irradiation strength (mA) of the electron beam increases, the probability of electron impact on the material accordingly rises, which may lead to increase removal efficiency. The results of the present study show that the continuous electron beam process using additives achieved more effective removal efficiency than either individual process (wet-scrubbing or EB irradiation only).

• 한국대기환경학회지
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• 제23권2호
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• pp.183-190
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• 2007

In this study, we have investigated waste incinerators which are one of the major HAPs emission sources. In order to obtain more reliable HAPs emission data from waste incinerators, direct sampling for the possible pollutants from the stack was carried out and the analysis was performed. The purpose of study was to understand the emission status from waste incinerators and recognize the problems and finally to set up a strategy to reduce the HAPs emissions from waste incinerators. The emission concentrations of 8 species of heavy metals and 16 species of PAHs have been analyzed for the first time in Korea. Not only the emission characteristics of HAPs from waste incinerators were identified, but also the analysis of reduction efficiencies for control devices such as BF and wet scrubbing systems was carried out.

• 멤브레인
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• 제15권1호
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• pp.70-83
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• 2005

폭기조를 간헐 폭기로 운전하여 호기/무산소(oxic/anoxic) 시간 비율과 무산소 조건에서 호기 조건으로의 전환시 공기세정이 투과플럭스 및 투과압력에 미치는 영향을 조사하였으며, 호기조건에서 무산소 조건으로 전환 시 펌프의 회전력에 의한 흡인압력이 투과플럭스와 투과 압력에 주는 영향을 조사하였다. 또한 긴 슬러지체류시간(SRT; Sludge Retention Time)과 고농도의 MLSS 유지시에 발생하는 미생물 대사산물이 분리막에 미치는 영향과 응집제를 투여하였을 때 분리막에 작용하는 플러스 효과에 대하여 조사하여 보았다. 호기/무산소(oxic/anoxic)의 시간비율에 따른 유기물 및 질소 제거효율을 조사해본 결과 폭기 40 비폭기 20분의 시간배분 조건에서 처리효율이 가장 양호하였으므로 호기/무산소(oxic/anoxic) 조건을 40/20분으로 한 조건(step-7)에서 약품주입 실험을 수행하였다. 액체 명반을 폭기조에 직접 투여할 경우 약품의 농도가 질산화 및 탈질 미생물에 많은 영향을 주는 것을 알 수 있었으며, MBR공정에서 인 1 mg/L를 제거하기 위해서는 약 0.7 mg/L의 액체명반이 필요한 것으로 확인되었다.

• KSBB Journal
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• 제22권3호
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• pp.151-156
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• 2007

본 논문은 식물정유를 이용해 유해가스를 처리하는 경우에 식물정유의 주요 구성성분을 파악하고 이를 통해 처리효율을 규명하는데 연구하였다. 또한 식물정유와 메틸 멀캅탄 악취가스에 의한 메틸 멀캅탄 악취가스 제거반응 메카니즘을 규명하였으며 그 결과는 아래와 같다. 1) 악취가스 중 메틸 멀캅탄 악취가스는 식물정유 추출물과 중화반응에 의해 처리될 수 있음을 나타내었다. GC-MS분석에 의한 식물정유 추출물의 성분 중 식물정유의 화학구조는 알코올기, 케톤기, 에스터기가 관여하는 것으로 나타났다. 충전탑내 식물추출물의 순환속도의 실험결과에서 중화반응으로 메틸 멀캅탄 악취가스가 제거되는 메카니즘은 앞서 언급한 화학작용기와 메틸 멀캅탄 악취가스의 중화반응에 의해 염을 형성하여 제거되는 과정을 갖는다. 2) 메틸 멀캅탄 악취가스 제거효율은 식물정유 추출물의 희석비와 스프레이 분무속도 그리고 초기 메틸 멀캅탄 악취가스 농도 등에 따라 달라질 수가 있음을 알 수 있었다. 시험결과는 식물정유 추출물의 희석비와 스프레이 분무속도 그리고 초기 메틸 멀캅탄 악취가스 농도가 희박한 경우에 최대 98%의 제거효율을 얻을 수가 있었다.