| Autor: |
Kim, Kyunghoon, Park, Gyutae, Kang, Seokwon, Singh, Rahul, Song, Jeongin, Choi, Siyoung, Park, Inseon, Yu, Dong-Gil, Kim, Myeong-Bok, Bae, Min-Suk, Jung, Suna, Chang, YuWoon, Park, Jonghun, Jung, Hae-Jin, Lim, Yong-jae, Lee, Taehyoung |
| Zdroj: |
Asian Journal of Atmospheric Environment; December 2021, Vol. 15 Issue: 4 |
| Abstrakt: |
Ammonia (NH3) is an important, albeit sticky, precursor for producing secondary inorganic aerosols (SIA), especially in the form of ammonium nitrate (NH4NO3) and ammonium sulfate ((NH4)2SO4). To reduce SIAs, many researchers have attempted to measure the concentration of ambient NH3using real-time or passive methods. However, NH3is a highly sticky gas and is therefore difficult to measure using real-time methods without incurring losses during measurement. In this study, four different tubing materials, semi seamless tubes, perfluoroalkoxy (PFA), polytetrafluoroethylene (PTFE), and polyvinylidene fluoride (PVDF), were used to ascertain the adsorption of NH3in inlets using real-time instruments. Without heating sample tubes and at 0% relative humidity (RH), this study shows that PTFE had the least adsorption(i.e., 0% at 1 and 2m of sample tube), and semi-seamless tubes had the highest adsorption (i.e., 27.5% at 1 m of sample tube). To calculate the adsorption of NH3under ambient conditions, at various inlet lengths, the RH of NH3was varied from 20% to 80%, which showed that shorter inlets and higher RH lower NH3adsorption at inlets (i.e., 1.74 ppb m-1at 80% RH and 7.48 ppb m-1at 20% RH). Additionally, inlet heating was effective in reducing the adsorption of NH3as the RH decreased. Applying the inlet system (i.e., 2 m of PTFE tube with heating) showed excellent correlation (slope: 0.995 and coefficient: 0.992) between two different real-time measurements while measuring ambient air. |
| Databáze: |
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