대기 중 HONO의 생성 반응 및 전환 기작에 관한 연구

김경찬,이춘상,한상우,최다영,이상준,엄지원,이수빈,한진석 한국도시환경학회 2021 한국도시환경학회지 Vol.21 No.4

This study was designed to identify major atmospheric HONO sources that trigger the accumulation of ozone by generating OH radicals through its photolysis. We measured HONO in the atmosphere using the PPDS-IC system and found that HONO concentration was 2.61 ± 1.91 ppb in the winter and 1.8 ± 0.76 ppb in the summer. Regardless of seasons, HONO concentration tended to be proportional to the NO2 level, and the HONO/NO2 ratio was greatly influenced by relative humidity. The conversion rate of HONO from NO2 was similar in winter and summer, but the variation of HONO in winter was larger than that of summer. Although the photolysis rate of HONO was lower in the winter, but the OH production rate was larger in the winter due to its higher concentrations observed. In addition to nighttime heterogeneous production with NO2, unknown sources played the very important role in the HONO budget, especially in the daytime and they should be resolved in future studies. 본 연구는 광분해를 통해 OH 라디칼을 생성하여 대기 중 오존의 축적을 촉발하는 HONO의 생성 특성 및 전환 기작을 분류하고 주도적인 반응을 규명하고자 하였다. 먼저 PPDS-IC 시스템을 사용하여 대기 중 HONO의 농도를 측정한 결과 겨울철의 평균농도는 여름철에 비해 약 1.4배 높은 수준으로 측정되었다. 겨울철과 여름철 두 계절 모두 NO2 농도 수준이 증가함에 비례하여 HONO 농도도 증가하는 경향을 나타냈으며, HONO/NO2 비는 습도 수준에 비례하는 경향을 나타냈다. NO2로부터 HONO의 전환율은 겨울철과 여름철이 비슷한 수준이었으며, 겨울철이 여름철에 비해 HONO의 농도변화 폭이 더 크게 나타났다. 태양천정각을 변수로 한 HONO의 광분해율은 여름철이 겨울철 대비 큰 수준이었지만, OH 생성률은 겨울철이 비교적 크게 나타났다. HONO의 감소 기작 중 가장 주도적인 경로는 낮시간 광분해인 것으로 추정되며, 생성 기작의 경우 미지의 생성 기작과 NO2의 비균질 반응이 가장 주도적인 두 개의 경로인 것으로 판단되었다.

Investigation of nitrous acid concentration in an indoor environment using an in-situ monitoring system

Park, Seung Shik,Hong, Jin H.,Lee, Jai H.,Kim, Young J.,Cho, Sung Y.,Kim, Seung J. Elsevier 2008 Atmospheric environment Vol.42 No.27

<P><B>Abstract</B></P><P>An in-situ measurement system for the determination of nitrous acid (HONO) was developed and used at an indoor residential environment. The system uses a diffusion scrubber to sample gaseous HONO and the peroxynitrite-induced luminol chemiluminescent method to quantify the amount of HONO. In this system, the detection limit of HONO, estimated as three times the noise level of the scrubbing solution blank, was 120pptv for a 2-min integrated sample. Indoor HONO and NO<I><SUB>x</SUB></I> concentrations were determined for 7 days in the living room of an apartment with a gas range for cooking in the kitchen. Close examination of the relationships among HONO, NO, and NO<SUB>2</SUB> concentrations during both the background and combustion periods confirm that the observed HONO was formed not only by direct emission from gas combustion, but also from heterogeneous reactions of NO<SUB>2</SUB> with H<SUB>2</SUB>O on indoor surfaces. The average ratio of HONO to NO<SUB>2</SUB> over the study period was 0.12±0.05. The HONO/NO<SUB>2</SUB> concentration ratio was 0.04–0.08 during the combustion period, whereas it was 0.10–0.25 after combustion had stopped. This suggests that HONO was generated through different production processes, both during combustion and after the completion of combustion. The controlled combustion experiments indicate that the burning rate is an important factor to determine the peak HONO concentration. In darkness, HONO had a nearly constant removal rate for all of the combustion experiments, whereas the removal rates of NO and NO<SUB>2</SUB> depended on the burning rates of the gas range. Combustion experiments conducted at the fixed burning rate setting show also that ventilation decreased HONO concentration. This indicates that the airflow rate of the range hood fan is an important factor to control the concentration of indoor air pollutants.</P>

2021~2022년 서울 도심에서 측정된 HONO의 변화 특성

길준수,이미혜,이현민,장지희 한국대기환경학회 2023 한국대기환경학회지 Vol.39 No.3

HONO takes up a large amount of urban OH budget in the early morning through photolysis and is one of the major reactive nitrogen oxides (NOy) that finally contributes to the enhancement of daytime O3 and potentially PM2.5 nitrate (NO3 -). Therefore, it is important to figure out the distribution and characteristics of HONO to understand the formation mechanisms of O3 and NO3 - in urban areas. In this study, real-time HONO measurement was conducted in Seoul, South Korea from 2021 to 2022 using the MARGA (Monitor for AeRosol and Gases in Ambient air) system. During the whole measurement period, average concentration of HONO was 0.96 ppbv, and it was higher in the cold season when the NO2 concentration was high. Regardless of the season, HONO increased with an increase in NO2 and relative humidity, indicating that the HONO in Seoul was influenced by the heterogeneous formation. In addition, the impact of HONO on O3 was differed on the season, and HONO showed the possibility to contribute to the NO3 - during both daytime and nighttime via formation-loss process.

주거환경 실내공기 중 NO₂와 HONO 농도 분포 특성

김윤신,박찬정,김순신,신현우,이석용,이준혁,양원호,이철민 한국실내환경학회 2013 한국실내환경학회지 Vol.10 No.2

The objective of this study is to offer basic scientific data to support policy decision-making for the improved control of nitrogen dioxide(NO₂) and nitrous acid(HONO) in residence. The survey on concentration of NO₂and HONO in 20 houses in Seoul and Daegu was performed from January to February, 2013. Average NO₂concentrations in the kitchen, living room, and room were 25.7 ± 7.7 ppb, 24.3 ± 8.5 ppb, and 19.6 ± 5.6 ppb, respectively. Also, average HONO concentration were 3.6 ± 1.0 ppb, 3.1 ± 0.9 ppb, and 3.1 ± 0.9 ppb, respectively. NO₂and HONO concentration in kitchen were significantly higher than the concentration in the living room and room(p<0.05). Concentration ratios of HONO/NO2 were ranged to 0.070 0.277 for indoor air and 0.004 0.161 for outdoor air. Indoor HONO/NO2 ratios were higher than the outdoor HONO/NO₂ratios.

적외선양자폭포레이저와 차등흡광법을 이용한 대기 중 HONO와 H2O2의 동시 연속 측정 타당성 연구

안준영 ( Joon Young Ahn ),박진수 ( Jin Su Park ),최진수 ( Jin Su Choi ),임재현 ( Jae Hyun Lim ),정유미 ( Yoo Mi Chung ),이강웅 ( Gang Woong Lee ) 한국환경분석학회 2013 환경분석과 독성보건 Vol.16 No.1

We tested a tunable laser differential absorption spectrometer with two mid-infrared continuous-wave mode quantum cascade lasers (cw-QCLs) for simultaneous measurements of nitrous acid (HONO) and hydrogen peroxide (H2O2) in the remote marine atmosphere at Baengyeong Island, Korea in October 2012. Two lasers scanned frequencies that covered approximately 0.2 cm-1 near at 1277.15 cm-1 and 1283.3 cm-1 for HONO and H2O2, respectively with resolution of about 0.001 cm-1 per channel. Ambient air sample was drawn to a 260 m multi-pass astigmatic sampling path cell at reduced pressure and light transmissions along predefined frequency ranges were detected at two peltier cooled HgCdTe detectors. The resulting one hour detection limits based on 2 s of background signal noise are 0.17 ppbv for HONO and 0.12 ppbv for H2O2. The concentrations over the measurement periods varied from below the detection limit to 0.8 ppbv for HONO, and from 0.5 ppbv to 0.8 ppbv for H2O2, respectively. Sensitivities and detection limits for QC-TILDAS of HONO and H2O2 were acceptable for their continuous monitoring in the remote background air. However, we found that further improvement could be achieved by the stabilizing intensities of transmitted laser light sources and reducing the humidity interferences.

Development of an activated carbon filter to remove NO₂ and HONO in indoor air

Yoo, Jun Young,Park, Chan Jung,Kim, Ki Yeong,Son, Youn-Suk,Kang, Choong-Min,Wolfson, Jack M.,Jung, In-Ha,Lee, Sung-Joo,Koutrakis, Petros Elsevier 2015 Journal of hazardous materials Vol.289 No.-

<P><B>Abstract</B></P> <P>To obtain the optimum removal efficiency of NO<SUB>2</SUB> and HONO by coated activated carbon (ACs), the influencing factors, including the loading rate, metal and non-metal precursors, and mixture ratios, were investigated. The NO<I> <SUB>x</SUB> </I> removal efficiency (RE) for K, with the same loading (1.0wt.%), was generally higher than for those loaded with Cu or Mn. The RE of NO<SUB>2</SUB> was also higher when KOH was used as the K precursor, compared to other K precursors (KI, KNO<SUB>3</SUB>, and KMnO<SUB>4</SUB>). In addition, the REs by the ACs loaded with K were approximately 38–55% higher than those by uncoated ACs. Overall, the REs (above 95%) of HONO and NO<I> <SUB>x</SUB> </I> with 3% KOH were the highest of the coated AC filters that were tested. Additionally, the REs of NO<I> <SUB>x</SUB> </I> and HONO using a mixing ratio of 6 (2.5% PABA (<I>p</I>-aminobenzoic acid)+6% H<SUB>3</SUB>PO<SUB>4</SUB>):4 (3% KOH) were the highest of all the coatings tested (both metal and non-metal). The results of this study show that AC loaded with various coatings has the potential to effectively reduce NO<SUB>2</SUB> and HONO levels in indoor air.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This study developed an activated carbon to simultaneously remove both NO<SUB>2</SUB> and HONO. </LI> <LI> We investigated various factors (loading rate, metal precursors, and mixture ratios). </LI> <LI> NO<SUB>2</SUB> and HONO could be efficiently removed by an improved activated carbon filter that was impregnated with two types of compounds (2.5% PABA+6% H<SUB>3</SUB>PO<SUB>4</SUB> and 3% KOH). </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Possible particulate nitrite formation and its atmospheric implications inferred from the observations in Seoul, Korea

Song, C.H.,Park, M.E.,Lee, E.J.,Lee, J.H.,Lee, B.K.,Lee, D.S.,Kim, J.,Han, J.S.,Moon, K.J.,Kondo, Y. Pergamon Press ; Elsevier [distribution] 2009 Atmospheric environment Vol.43 No.13

Simultaneous measurements of gaseous species and fine-mode, particulate inorganic components were performed at the University of Seoul, Seoul in Korea. In the simultaneous measurements, a certain level of nitrous acid (HONO) was observed in the gas-phase, indicating possible heterogeneous HONO production on the surface of the ambient aerosols. On the other hand, high particulate nitrite (NO<SUP>2-</SUP>) concentrations of 1.41(+/-2.26)μg/m<SUP>3</SUP> were also measured, which sometimes reached 18.54μg/m<SUP>3</SUP>. In contrast, low HONO-to-NO<SUB>2</SUB> ratios of 0.007(+/-0.006) were observed in Seoul. This indicates that a significant fraction of HONO is dissolved in atmospheric aerosols. Around the Seoul site, sufficient alkalinity may have been provided to the atmospheric aerosols from the excessive presence of NH<SUB>3</SUB> in the gas-phase. Due to the alkaline particulate conditions (defined in this study as a particle pH >∼3.29), the HONO molecules produced at the surface of the atmospheric aerosols appeared to have been converted into particulate nitrite, thereby preventing their further participation in the atmospheric O<SUB>3</SUB>/NO<SUB>y</SUB>/HO<SUB>x</SUB> photochemical cycles. It was estimated that a minimum average of 65% of HONO was captured by alkaline, anthropogenic, urban particles in the Seoul measurements.

일본 메이지신궁(明治神宮) 봉납스모(奉納相撲)의 기원 및 사회문화적 맥락

김용의 중앙대학교 일본연구소 2019 日本 硏究 Vol.0 No.50

Japanese sumo wrestled with the festivities of the shrine. This continues to this day. In particular, shrines with a special historical, social and cultural status such as the Meiji Jingu Shrine, Ise Jingu Shrine and Yasukuni Shrine regularly perform ceremonies related to sumo wrestling. In this paper, the origins and changes of the Japanese Meiji Jingu Hono-sumo(奉納相撲) were examined with a focus on the socio - cultural context of the time.The socio-cultural context in which Meiji Jingu shogunate sumo wrestlers can be summarized as follows. First, before the modern era, there was a base that had enjoyed watching sumo. Second, it originated from the folk tradition of dedicating sumo to the rituals of shrines and temples throughout the country since the modern era. Third, in the process of modernization, when Sumo was in danger of being abolished, Sumo Association officials strengthened their relationship with Shinto, including Meiji Shrine, as a self-help measure to escape the crisis. Fourth, it is consistent with the historical, political, and social context of strengthening nationalism as a whole. Fifth, the same socio-cultural context was combined with the so-called “national flag sumo”.

2018년 여름 서울의 HONO 분포특성 및 광화학 영향

길준수,손지원,강성구,박준형,이미혜,전은미,심미희 한국대기환경학회 2020 한국대기환경학회지 Vol.36 No.5

HONO photolysis is an early morning source of OH radicals in urban environment, which expedites the photooxidation of volatile organic compounds (VOC), leading to O3 production. From July 14th to August 22nd 2018, HONO was measured at Korea University using a parallel plate diffusion scrubber coupled with Ion Chromatography (PPDS-IC), in conjunction with major reactive gases (O3, NO, and NO2). The collection efficiency of PPDS was estimated as 91.8~99.9% from the side-by-side measurement. HONO mixing ratio ranged between 0.01 to 0.79 ppbv with a mean of 0.28 ppbv, which was higher in high-O3 episode than non-episode. Likewise, the OH production from HONO photolysis was higher by 0.04 pptv sec-1 in high-O3 episodes, when the daily maximum O3 exceeded 100 ppbv, than non-episode. The hourly maximum O3 reached 170 ppbv under severe heat waves. When the diurnal variations of O3 was simulated with the measured HONO using the Framework for 0-D Atmospheric Modelling (F0AM), the daily maximum O3 changed by 8~17 ppbv according to the HONO and VOC levels. In particular, the daily maximum O3 was increased under non-episode conditions with an increased HONO, albeit low level.

Simultaneous Measurements of Gaseous Nitrous Acid and Particulate Nitrite Using Diffusion Scrubber/Steam Chamber/Luminol Chemiluminescence

Sangbum Hong,Jungho Choi,Jai H. Lee,Wonil Chang 대한화학회 2008 Bulletin of the Korean Chemical Society Vol.29 No.8

An instrument was developed for the simultaneous determination of gas- and aerosol-phase nitrous acid (HONO). Gaseous HONO (HONO(g)) was sampled by a diffusion scrubber and particulate nitrite (NO2 −(p)) was collected by a particle growth chamber. The collected samples were analyzed in time-sharing manner, based on the peroxynitrite-induced luminol chemiluminescence. The automated system was found to be sensitive with 13 pptv of detection limit, fast with 4 min. of sampling frequency, and simple and affordable to construct and operate. The system was optimized by adjusting the experimental parameters. The system was applied to the field measurement of gas- and particle-phase HONO during the springtime of 2004 in Gwangju, South Korea. HONO(g) concentrations varied diurnally from 200 pptv around 3 P.M. to 800 pptv at 5 A.M. The variation of NO2 −(p) was not significant with the maximum of 240 pptv at 11 P.M. and the minimum of 170 pptv at 4 P.M., not displaying distinct characteristics.