• 조명전기설비학회논문지
• /
• 제22권12호
• /
• pp.142-149
• /
• 2008

본 논문은 비열평형 플라즈마와 촉매를 이용하여 트리클로로에틸렌의 효과적인 분해방법을 제안하였다. 이를 위하여 이산화망간과 알루미나 펠렛을 플라즈마 리액터 내부에 충진한 리액터를 설계하였다. 이산화망간 충진 리백터를 이용할 경우에는 산소를 포함한 가스중의 방전에 의해 발생된 오존이 촉매 표면에서 분해되는 동안에 발생된 산소원자 라디칼에 의하여 TCE의 분해율이 향상됨을 알 수 있었다. 그리고 알루미나를 충진한 경우에는 TCE DCAC로 산화되었으며, COx 및 $Cl_2$와 같은 저분자상으로 많이 분해되지 않았다. 그러나 알루미나 충진 리액터에 의한 플라즈마 처리된 가스를 리액터 후단에 설치한 이산화망간 촉매를 통과시킴에 의하여 분해율이 매우 향상됨을 알 수 있었다. 따라서, 플라즈마 프로세스에 이산화망간을 응용함에 의하여 오존 분해에 따른 촉매 표면의 산소원자 라디칼에 의하여 TCE 및 분해 생성물(DCAC)를 효율적으로 분해하는 것이 가능하다.

• 조명전기설비학회논문지
• /
• 제25권10호
• /
• pp.116-124
• /
• 2011

In this work, the effect of the initial concentration of methanol and ethanol, and the addition of oxygen molecules were discussed to improve the hydrogen generation using non-thermal plasma reactor effectively. In addition, the effect of ozone decomposition catalyst of manganese dioxide and its quantity was investigated. First, hydrogen concentration increased until an initial concentration of about 40,000[ppm] of methanol and thereafter it was saturated. Henceforth, hydrogen concentration decreased with increasing the oxygen percent on the carrier gas of nitrogen about both substances. Related with the effect of catalyst, it increased upto 60[g], but it was not changed largely after that. Consequently, it is confirmed that the hybrid process using plasma process and catalytic surface chemical reaction is a very promising way to increase the efficiency of hydrogen generation as investigated in this work.

• 산업기술연구
• /
• 제27권A호
• /
• pp.25-29
• /
• 2007

Ozone alone, Ozone/GAC, Ozone/$H_2O_2$ and Ozone/GAC/$H_2O_2$ processes were introduced for treatment of humic acid, which is a representative refractory organic compound. $H_2O_2$ and GAC used as catalysts for experiment. The treatment efficiencies of humic acid in each process were analyzed for pH variation, DOC removal, and $UV_{254}$ decrease. $UV_{254}$ decrease in Ozone/GAC and Ozone/GAC/$H_2O_2$ processes were the highest with about 93%, and Ozone alone and Ozone/$H_2O_2$ processes were 88%. DOC removal in Ozone/GAC/$H_2O_2$ process was the highest with 71%. Removal by Ozone/GAC, Ozone alone, and Ozone/$H_2O_2$ processes were 66%, 39%, and 47%, respectively.

• 공업화학
• /
• 제20권1호
• /
• pp.87-93
• /
• 2009

팔라듐 금속을 활성탄과 알루미나에 담지시켜 Pd/AC (Pd/활성탄), Pd/AO (Pd/알루미나) 촉매를 제조하고, 오존/촉매공정에 적용하여 담지체의 종류에 따른 촉매 특성을 비교하였다. 담지체를 달리한 촉매 일정량을 오존포화수에 투입하고 오존분해능을 비교해 본 결과, 담지체의 종류에 따른 효율의 변화는 없었다. 오존단독공정과 Pd/AC, Pd/AO 촉매를 이용한 오존/촉매공정에서 dichloroacetic acid (DCAA)의 분해율 및 산화특성(TOC, $COD_{Cr}$)을 비교해 본 결과, 오존/촉매공정의 제거효율이 높았으며, 담지체에 따른 특성변화는 거의 없었다. DCAA 농도를 일정하게 하고 오존공급량을 변화시켜 제거율을 확인한 결과, 어느 수준까지는 오존공급량 증가에 따라 제거율이 상승하였지만, 1.0 L/min 이상의 오존공급량에서는 공급량에 비례하여 제거율이 상승하지 않았다. 이러한 원인은 DCAA의 완전산화에 의해 생성된 중탄산염과 분해과정에서 발생된 염소이온이 하이드록실 라디칼(${\cdot}OH$)의 스케빈저(scavenger)로 작용한 것 같았다.

• 한국환경과학회지
• /
• 제16권4호
• /
• pp.433-440
• /
• 2007

The photodegradation and by-products of the gaseous toluene with $TiO_2$ (P25) and short-wavelength UV ($UV_{254+185nm}$) radiation were studied. The toluene was decomposed and mineralized efficiently owed to the synergistic effect of photochemical oxidation in the gas phase and photocatalytic oxidation on the $TiO_2$ surface. The toluene by the $UV_{254+185nm}$ photoirradiated $TiO_2$ were mainly mineralized $CO_2$ and CO, but some water-soluble organic intermediates were also formed under severe reaction conditions. The ozone and secondary organic aerosol were produced as undesirable by-products. It was found that wet scrubber was useful as post-treatment to remove water-soluble organic intermediates. Excess ozone could be easily removed by means of a $MnO_2$ ozone-decomposition catalyst. It was also observed that the $MnO_2$ catalyst could decompose organic compounds by using oxygen reactive species formed in process of ozone decomposition.

• 한국환경과학회지
• /
• 제18권4호
• /
• pp.445-450
• /
• 2009

In this study, the fundamental experiments were performed for catalytic oxidation of NO (50 ppm) on $MnO_2$ in the presence of ozone. The experiments were carried out at various catalytic temperatures ($30-120^{\circ}C$) and ozone concentrations (50-150 ppm) to investigate the behavior of NO oxidation. The honeycomb type $MnO_2$ catalyst was rectangular with a cell density of 300 cells per square inch. Due to $O_3$ injection, NO reacted with $O_3$ to form $NO_2$, which was adsorbed at the $MnO_2$ surface. The excessive ozone was decomposed to $O^*$ onto the $MnO_2$ catalyst bed, and then that $O^*$ was reacted with $NO_2$ to form $NO_3^-$. It was found that the optimal $O_3$/NO ratio for catalytic oxidation of NO on $MnO_2$ was 2.0, and the NO removal efficiency on $MnO_2$ was 83% at $30^{\circ}C$. As a result, NO was converted mainly to $NO_3^-$.

• 웰빙융합연구
• /
• 제5권2호
• /
• pp.21-27
• /
• 2022

Purpose: This study is about photocatalytic technology and plasma oxidation-reduction technology. To the main cause of exposure to odor pollution, two deodorization techniques were applied to develop a module with higher removal efficiency and ozone reduction effect. Research design, data and methodology: A composite module was constructed by arranging two types of dry deodorization equipment (catalyst, adsorbent) in one module. This method was designed to increase the responsiveness to the components of complex odors and the environment. standard, unity, two types of oxidizing photo-catalyst technology and plasma dry deodorization device installed in one module to increase the potential by reduction to 76% of ozone, 100%, and 82%. Results: The complex odor disposal efficiency was 92%. Ammonia was processed with 50% hydrogen sulfide and 100% hydrogen sulfide, and ozone was 0.01ppm, achieving a target value of 0.07ppm or less. The combined odor showed a disposal efficiency of 93%, ammonia was 82% and hydrogen sulfide was 100% processed, and ozone achieved a target value of 0.07 ppm or less. Conclusions: Ozone removal efficiency was 76% by increasing Oxidation-Reduction Reaction(ORR). The H2S removal efficiency of the deodorizer was higher than that of the biofilter system currently used in sewage disposal plants.

• 산업기술연구
• /
• 제28권A호
• /
• pp.23-26
• /
• 2008

Ozone/GAC and ozone-GAC processes were introduced for treatment of humic acid, which is representative refractory organic compound. The treatment efficiencies of humic acid in each process were analyzed in pH variation, DOC removal, and $UV_{254}$ decrease. $UV_{254}$ decrease in all processes was comparatively high with efficiency over 92%. $UV_{254}$ decrease in ozone alone process was 85%. DOC removal in Ozone-GAC process was the highest with 75%. Removal by Ozone/GAC, Ozone alone processes were 71% and 33% respectively.

• 한국물환경학회지
• /
• 제20권2호
• /
• pp.176-182
• /
• 2004

The purpose of this study was to investigate the heterogeneous catalytic ozonation of oxalic acid by manganese (Mn) doped-granular activated carbon (GAC). In order to observe the effect of the amount of Mn doped on GAC, catalysts were manufactured by varying the impregnated Mn concentration. In this paper, the following had labeled all sorts kinds of Mn-doped GAC were labeled with suitable names according to the amount (mM) of the concentration of dipping solution: They were each named as 'Mn20', 'Mn50', 'Mn100' and 'Mn200'. These experiments were performed in a batch reactor (0.5 L) and a semi-batch reactor (1 L) and Mn-free GAC was used as a blank catalyst. The ozone decay properties of each manufactured catalyst were firstly investigated to find out the reactivity between the aqueous ozone and the catalysts. Oxalic acid removal by catalytic ozonation was then performed to demonstrate the oxidative efficiencies of each catalyst.

• 한국환경과학회지
• /
• 제15권3호
• /
• pp.193-201
• /
• 2006

Advanced oxidation processes involving $O_3/H_2O_2$ and $O_3/catalyst$ were used to compare the degradability and the effect of pH on the oxidation of 1,4-dioxane, Oxidation processes were carried out in a bubble column reactor under different pH. Initial hydrogen peroxide concentration was 3.52 mM in $O_3/H_2O_2$ process and 115 g/L (0.65 wt.%) of activated carbon impregnated with palladium was packed in $O_3/catalyst$ column. 1,4-dioxane concentration was reduced steadily with reaction time in $O_3/H_2O_2$ oxidation process, however, in case of $O_3/catalyst$ process, about $50{\sim}75%$ of 1,4-dioxane was degraded only in 5 minutes after reaction. Overall reaction efficiency of $O_3/catalyst$ was also higher than that of $O_3/H_2O_2$ process. TOC and $COD_{cr}$ were analyzed in order to examine the oxidation characteristics with $O_3/H_2O_2\;and\;O_3/catalyst$ process. The results of $COD_{cr}$ removal efficiency and ${\Delta}TOC/{\Delta}ThOC$ ratio in $O_3/catalyst$ process gave that this process could more proceed the oxidation reaction than $O_3/H_2O_2$ oxidation process. Therefore, it was considered that $O_3/catalyst$ advanced oxidation process could be used as a effective oxidation process for removing non-degradable toxic organic materials.