초음파분해반응에 있어서 회가스의 영향

임봉빈,김선태 한국환경과학회 2002 한국환경과학회지 Vol.11 No.7

The effects of noble gas (such as helium, neon, argon, krypton, and xenon) on the sonolytic decomposition of water and 2-methyl-2-propanol(t-butanol) with 200 ㎑ high power ultrasound were investigated. The physical properties of the noble gas have an effect on the formation rate of products (H_2O_2, H_2, O_2) and the decomposition rate on the sonolytic decomposition of water. The pyrolysis products, such as methane, ethane, ethylene, and acetylene are formed during the sonolytic decomposition of t-butanol. From the estimation of the ratio [C_2H_4 + C_2H_2] / [C_2H_6], the cavitation temperature would be varied by the used noble gas. In all cases for the sonolytic decomposition of water, t-butanol, and diethyl phthalate, the decomposition rates were xenon > krypton > argon > neon > helium with a significant difference and were closely correlated with the formation rate of OH radical and high temperature inside the cavitation bubble under each noble gas.

Evaluation of an Ammonia Passive Sampler Using Chamber System

임봉빈,김선태 한국대기환경학회 2006 한국대기환경학회지 Vol.22 No.E1

The purpose of this study was to evaluate the efciency of a passive sampler in measuring atmosphericammonia concentrations using chamber system. The ability of the passive sampler to quantitatively deter-mine atmospheric ammonia gas was almost identical to that of the reference method (indophenol method).quantification limits of the ammonia passive sampler were 16.9 ppb and 25.3 ppb, respectively, for a 24-hsampling period. The average coefficient of variation between replicated samplers was 6.7± 4.2%. Theconcentrations measured by the two methods (passive sampler and indophenol method) were no significantdifference with good a correlation(correlation coefcient= 0.964).

Sodium Dodecylbenzene Sulfonate 수용액의 분해반응에서 초음파 효과

임봉빈,Yim, Bong-Been 대한화학회 2004 대한화학회지 Vol.48 No.6

계면활성제 중 sodium dodecylbenzene sulfonate(DBS) 수용액에 초음파(200 W, 6 $W/cm^2$)를 조사하여 주파수, 용존가스 및 농도에 따른 분해경향을 조사하였다. 주파수에 따른 초음파 분해속도는 50 kHz와 600 kHz보다 200 kHz에서 가장 빠른 것으로 나타났다. 200 kHz의 초음파를 이용한 DBS의 분해반응에서는 산소를 이용하였을 때 가장 빠른 분해속도를 나타내었으며, 질소의 경우가 가장 늦은 분해속도를 나타내 초음파반응에 사용된 용존가스(산소, 공기, 질소, 아르곤, 헬륨)의 물리적성질과 활성라디칼의 생성에 의해 분해속도가 달라졌음을 알 수 있다. DBS의 농도에 따른 초음파분해 경향을 보면, 1 mM 까지 분해속도의 감소가 뚜렷하게 나타났으며, DBS의 critical micelle concentration(3 mM) 부근을 기준으로 분해속도의 변화가 거의 나타나지 않아 계면활성제의 미셀형성이 초음파에 의해 유도되는 라디칼에 의한 산화반응과 버블계면에서의 열분해반응에 영향을 미치는 것으로 생각된다. The influence of ultrasound frequency, dissolved gases, and initial concentration on the decomposition of sodium dodecylbenzene sulfonate(DBS) aqueous solution was investigated using ultrasound generator with 200 W ultrasound power. The decomposition rates at three frequencies(50, 200, and 600 kHz) examined under argon atmosphere were highest at 200 kHz. The highest observed decomposition rate at 200 kHz occurred in the presence of oxygen followed by air and argon, helium, and nitrogen. The effect of initial concentration of DBS on the ultrasonic decomposition was decreased with increasing initial concentration and would depend upon the formation of micelle in aqueous solution. It appears that the ultrasound frequency, dissolved gases, and initial concentration play an important role on the sonolysis of DBS. Sonolysis of DBS mainly take place at the interfacial region of cavitation bubbles by both OH radical attack and pyrolysis to alkyl chain, aromatic ring, and headgroup.

폐수와 상수원수의 악취평가를 위한 공기희석관능법과 희석배수치 시험법의 비교

임봉빈,허승호,안덕규,김선태 한국냄새환경학회 2014 실내환경 및 냄새 학회지 Vol.13 No.3

The object of this study is to investigate the relationship between the air dilution sensory test and the thresholdodor number (TON) method for evaluating the odor of domestic wastewater, plating plant wastewater, food plantwastewater and lake water. The dilution factor of raw wastewater evaluated by the air dilution sensory test wasin the order of food plant > plating plant > domestic > lake, and that evaluated by the threshold odor numbermethod was in the order of food plant > domestic > plating plant > lake. The same results were obtained whenthe raw wastewater and lake water were diluted 2 and 5 times with pure water. The relative geometric standarddeviation determined from the threshold values of each panel on the air dilution sensory test was much largerthan that calculated from results derived from the threshold odor number method. The relative geometric standarddeviation obtained from samples with a low dilution factor was greater. There was a very good linear correlation(correlation coefficient = 0.968~1.000) between the air dilution sensory test and the threshold odor number method. But, the reduction in odor intensity (the slopes of regression curves) by dilution was dependent on the types ofthe odor-emission sources.

Evaluation of Short-Term CO2 Passive Sampler for Monitoring Atmospheric CO2 Levels

임봉빈,김선태 한국기후변화학회 2016 한국기후변화학회지 Vol.7 No.1

In this study, we investigated the applicability of a short-term carbon dioxide (CO2) passive sampler using turbidity change in a solution containing barium hydroxide (Ba(OH)2). The mass of CO2 introduced into the Ba(OH)2 aqueous solution was strongly correlated (r2 = 0.9565) to the change in turbidity caused by its reaction with the solution. The sampling rates calculated for 1 h and 24 h were 42.4±5.4 mL min—1 and 2.3±0.3 mL min—1, respectively. Both unexposed (blank) and exposed samplers remained stable during the storage period of at least two weeks. The detection limits of the passive sampler for CO2 were 81.5 ppm for 1 h and 61.5 ppm for 24 h. Based on the results, the passive sampler using the change of turbidity in the Ba(OH)2 aqueous solution appears to be a suitable tool for measuring short-term atmospheric concentrations of CO2.

절대로 널 보낼 순 없어

임봉빈 샘터사 1988 월간 샘터 Vol.19 No.8

폐수와 상수원수의 악취평가를 위한 공기희석관능법과 희석배수치 시험법의 비교

임봉빈,허승호,안덕규,김선태 한국실내환경학회 2014 한국실내환경학회지 Vol.13 No.2

The object of this study is to investigate the relationship between the air dilution sensory test and the threshold odor number (TON) method for evaluating the odor of domestic wastewater, plating plant wastewater, food plant wastewater and lake water. The dilution factor of raw wastewater evaluated by the air dilution sensory test was in the order of food plant > plating plant > domestic > lake, and that evaluated by the threshold odor number method was in the order of food plant > domestic > plating plant > lake. The same results were obtained when the raw wastewater and lake water were diluted 2 and 5 times with pure water. The relative geometric standard deviation determined from the threshold values of each panel on the air dilution sensory test was much larger than that calculated from results derived from the threshold odor number method. The relative geometric standard deviation obtained from samples with a low dilution factor was greater. There was a very good linear correlation (correlation coefficient = 0.968~1.000) between the air dilution sensory test and the threshold odor number method. But, the reduction in odor intensity (the slopes of regression curves) by dilution was dependent on the types of the odor-emission sources.

3-Methyl-2-benzothiazolinone hydrazone을 이용한 포름알데히드 분자확산 측정방법의 평가

임봉빈,김선규,정의석 대한환경공학회 2005 대한환경공학회 학술발표논문집 Vol.2005 No.12

산업단지에서 Passive Sampler를 이용한 악취물질관련 카보닐화합물의 측정조사

임봉빈,권기은,손찬웅,김선태,정의석 한국대기환경학회 2009 한국대기환경학회 학술대회논문집 Vol.2009 No.10월

초음파조사에 의한 염화불화탄소(CFC)의 분해

임봉빈,김선태,平井恭三,前田泰昭 한국대기환경학회 2003 한국대기환경학회지 Vol.19 No.3

The sonolytic decomposition of chlorofluorocarbon(CFC 113) and several alternative compounds, such as HCFC 225 ca, HCFC 225cb, and HFC 134a, in aqucous solutions was investigated. The CFC 113 with a high volatility and a low solubility in water was rapidly decomposed with increasing sonication time. The decomposition rates were influenced by the initial concentration of CFC 113, the reaction temperature, and the gas/liquid phase volume ratio but were independent of the pH of solution. The predominant pathway of the decomposition of CFC 113 by sonocation was not the oxidation by OH radicals but the pyrolysis with high temperature and pressure inside of the cavitation bubble. The pyrolysis in the cavitation bubble resulted in an almost complete mineralization of CFC 113 with the high efficient formation of inorganic products(Cl^(-), F^(-), CO, CO₂). The addition of zine powder on the decomposition of CFC 113 by sonication caused an acceleration of the decomposition. Also, HCFCs and HFC 134a were found to be readily decomposed by the pyrolysis induced from the sonication.