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

• 환경위생공학
• /
• 제14권4호
• /
• pp.69-76
• /
• 1999

This research was carried but to investigate the characteristics of mist removal with the change of operating conditions in the plasma reactor of impulse streamer corona based on the distribution of particle size measured by laser diffraction spectrometers. The operating conditions in this experiment were power of impulse streamer corona, gas velocity, collection time, and SOx/NOx concentration. The collection efficiency T(d) was estimated by distribution of particle size in the collection zone through the advanced model.

• 한국연초학회지
• /
• 제2권1호
• /
• pp.8-16
• /
• 1980

Zeolite의 일종인 clinoptilolite를 담배필터 첨가제로 활용하는 연구를 하였다. 입자크기 30 $\pm$ 5 A.S.T.M. mesh의 clinoptilolite와 charcoal 1 : 1 (V/V)로 혼합하여 삼중필터의 cavity부분에 충진했을 때, 1. Cellulose acetate필터에 비하여 nicotine 35%, T.P..M.22%를 감소시켰으며, 2. Gas phase중 n-amyl alcohol등 aliphatic compound와 furan등 cyclic compound를 cellulose acetate filter에 비하여 60$\pm$ 5%를 감소시켰다. 3. Charcoal의 removal efficiency는 40-50% clinoptilolite의 10-20%에 비하여 큰 값이였지만 charcoal은 분자량이 큰 aromatic compound의 removal efficiency가 50$\pm$5%로서 aliphatic compound의 removal efficiency 40: 5%보다 큰 값이였음에 비하여 clinoptilolite는 alcohol과 ketone계열의 분자갹이 작은 화합물의 removal efficiency가 15-20%로 cyclic compounds의 removal efficiency 10-15%에 비하여 보다 큰 값이었다. 이 두물질의 gas phase성분의 흡착기능은 상호 보완적임을 알 수 있었다.

• Nuclear Engineering and Technology
• /
• 제52권10호
• /
• pp.2230-2237
• /
• 2020

Self-priming venturi scrubber is one of the most effective devices used to collect aerosols and soluble gas pollutants from gaseous stream during severe accident in a nuclear power plant. The present study focuses on investigation of dust particle removal efficiency of the venturi scrubber both experimentally and theoretically. Venturi scrubber captures the dust particles in tiny water droplets flowing into it. Inertial impaction is the main mechanism of particles collection in venturi scrubber. The water injected into venturi throat is in the form of jets through multiple holes present at venturi throat. In this study, aerosols removal efficiency of self-priming venturi scrubber was experimentally measured for different operating conditions. Alumina (Al₂O₃) particles with 0.4-㎛ diameter and 3950 kg/㎥ density were treated as aerosols. Removal efficiency was calculated for different gas flow rates i.e. 3-6 ㎥/h and liquid flow rates i.e. 0.009-0.025 ㎥/h. Experimental results depict that aerosols removal efficiency increases with the increase in throat velocity and liquid head. While at lower air flow rate of 3 ㎥/h, removal efficiency decreases with the increase in liquid head. A theoretical model of venturi scrubber was also employed and experimental results were compared with mathematical model. Experimental results are found to be in good agreement with theoretical results.

• 한국입자에어로졸학회지
• /
• 제9권4호
• /
• pp.239-246
• /
• 2013

The purpose of this study is to determine the feasibility of dry-type desulfurization process for actual application to coal-fired power plant. We used actual exhaust gas from Facility Y, Plant #2 to fabricate a demo-scale testing device to attempt to improve the efficiency of desulfurization. A spout-bed circulating dry scrubber convergence system connecting turbo reactor with bag filter was devised, then analyzed for performance characteristics of $SO_2$ removal for Ca/S mole ratio, superficial gas velocity, and ammonia injection, and for secondary reaction characteristics of the non-reactive sorbent at the bag filter. As a result, the installation of spout-bed circulating dry scrubber convergence system showed better economy and efficiency for removing sulfur than the existing wet/semidry-type desulfurization process. In addition, the best efficiency for desulfurization occurred when connected to the bag filter, with differential pressure maintained at 150 $mmH_2O$.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2008년도 춘계학술대회논문집
• /
• pp.260-263
• /
• 2008

KEPCO(Korea Electric Power Corporation) is performing the nation's first biogas-MGT project as an effort to encourage the utilization of wasted biogas which contains useful CH4. The goals of this project are to develop the Pretreatment system of Livestock bio-gas and set up the biogas-MGT co-generation system. The project will not only utilze flared biogas as precious energy but also improve the economics of the plant a lot. The pretreatment system mainly consists of sulfur removal tower, biogas compressor and many filtering systems. A computational fluid dynamics study in the bio gas sulfur removal tower and sulfur absorption filter was carried out. Understanding of the flow in the sulfur removal tower and sulfur adsorption filter obtained by this study can be used to identify the problems in the sulfur removal tower and to improve the sulfur removal efficiency of the sulfur removal tower. Resistance material modeling is used to simulate the sulfur adsorption filter, and the resistance coefficient was adjusted to reflect the experimental pressure loss value. And the pressure loss change with the flowrate is predicted

• 한국환경과학회지
• /
• 제15권3호
• /
• pp.211-219
• /
• 2006

An experimental study on the removal of VOCs gas using a biomembrane reactor were carried out at various inlet gas concentration, specific loading rate, retention time and gas flow rate of volume. The variations of efficiency and various parameters, which are relevant to gas removal, with mixing of soluble gas and without have been discussed. More than 95% of the toluene and methanol present in the feed was successfully removed in each study. The elimination of methanol with mixture of soluble compound of about 300 mg/h corresponds to a portion of 21% if there is a feed stream of 1400 mg/h. On the contrary the maximum efficiency of about 72% of toluene was reached. This is to be rated as a treatment of sorption that the limiting factor of the dismantling speed could be represented by this difficult degradable component. Nevertheless the elimination capacities for this reactor for toluene were on a very high level. For substances which show a very high solubility in silicon rubber an advantage of a bio membrane is clearly shown. Therefore a similarly good result is expected for n-hexane, because of its relatively good permeability which was distinguished during permeation experiments.

• 한국가스학회지
• /
• 제21권6호
• /
• pp.88-95
• /
• 2017

국내에서 독성가스의 사용은 반도체, 디스플레이 및 태양광 등 첨단산업의 발전에 따라 증가하고 있는 추세이다. 최근 5년간 국내 독성가스 소비량 현황을 살펴보면 연평균 12% 정도 증가 추세에 있지만, 아직까지 사용에만 관심이 집중되고 있고, 사후 처리나 안전에는 다소 소홀한 것이 사실이다. 2012년 9월 발생한 구미 불산 누출사고는 이러한 안전관리 부재를 단적으로 보여주는 사례이다. 이 사고로 인하여 정부, 업계 및 학계에서는 화학물질(독성가스) 누출사고 등에 대한 관심을 갖게 되었고, 정부 주도로 화학물질안전관리대책 등이 수립되어 추진되어 왔지만 아직까지 안전관리 사각지대가 많은 실정이다. 본 연구에서는 반도체, 디스플레이 업종에서 사용되는 저감설비에서 배출되는 가스상 물질에 대한 처리효율에 대한 효과적인 측정방법을 개발하는 것이 목적이다. 국립환경과학원과 UNFCCC에서 제시하는 반도체 & 디스플레이 업종에서 사용되는 온실가스 저감시설의 처리효율 측정방법 가이드라인에 대해 실증시험을 통해 맹독성가스 시설에도 오차 범위 내에서 적용 가능한지를 살펴보고 맹독성가스 저감시설에 대한 차별화된 효율성 측정 방법을 제시하였고, 독성가스 사고에 대한 선제적 예방을 위해서 독성가스 저감시설 등 안전설비에 대한 제3자 인증제도 도입의 필요성을 제안하였다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회B
• /
• pp.3413-3417
• /
• 2007

In recent semiconductor manufacturing clean rooms, air washers are used to remove airborne gaseous contaminants such as $NH_3$, SOx and organic gases from the outdoor air introduced into clean room. In the present study, an experiment was carried out to examine the improvement of removal efficiency for the gaseous contaminants. In order to improve the gas removal efficiency, a hot water contact heat exchanger was installed upstream of the air washer to heat and humidify the incoming outdoor air before entering the air washer.

• 한국분무공학회지
• /
• 제18권2호
• /
• pp.81-86
• /
• 2013

To comply with the regulation of the reinforcing Clean Air Conservation Act, it is necessary for the semiconductor manufacturers to develop effective low-concentration acid gas abatement system to treat the flue gas. The low-concentration acid gas was found to be harder to deal with than the high-concentration one. In this study, the effect of various potential treatments such as air-assist nozzle spraying, magnetizing the scrubbing water, and adding surfactants to spraying and scrubbing water were investigate through the application of the statistical ANCOVA method, which was proved to be very useful tool when the inlet concentration of acid gas could not be controlled precisely and it affected the removal efficiency of the abatement system.