Heterogeneous reaction of NO2 with hematite, goethite and magnetite: Implications for nitrate formation and iron solubility enhancement

Heterogeneous Reaction of CaCO3 With NO2 at Different Relative Humidities: Kinetics, Mechanisms, and Impacts on Aerosol Hygroscopicity

“…CaCO 3 (>99.5% Alfa Aesar) particles used in our work have a BET surface area of 2.18 ± 0.01 m 2 /g and an average diameter of 3.12 ± 0.56 μm (Chen et al., 2020). The particle‐loaded filters used for heterogeneous reactions were prepared according to the procedure used in our previous work (R. Li et al., 2020): (a) approximately 250 mg CaCO 3 particles were transferred into 500 mL HPLC‐grade ethanol, and the CaCO 3 /ethanol mixture (0.5 g/L) was stirred using a magnetic stirrer to keep it homogeneous; (b) 10 mL aqueous mixture was transferred onto a PTFE filter (47 mm in diameter, Whatman, USA) to form a particle film on the filter after ethanol was evaporated; (c) the mass of CaCO 3 particles on individual filters prepared was determined to be 5.0 ± 1.0 mg, via measuring the mass of filters before and after CaCO 3 particles were loaded. Particles were fairly evenly distributed on the filters, as confirmed by visual inspection.…”

“…Heterogeneous reaction of mineral dust with NO 2 , an important nitrogen oxide in the troposphere, may contribute significantly to the formation of aerosol nitrate and HONO (an important precursor of OH radicals) (Kumar et al., 2014; J. Li et al., 2012; Ndour et al., 2008; Y. Tang et al., 2004), and could thus affect the formation of O 3 (Dentener et al., 1996; Kumar et al., 2014; J. Li et al., 2012; Ndour et al., 2008; Y. Tang et al., 2004) and secondary aerosols (Dentener et al., 1996; Kumar et al., 2014; J. Li et al., 2012; Y. Tang et al., 2004). As a result, this reaction is of great interest and has been examined by a number of laboratory studies (Angelini et al., 2007; Borensen et al., 2000; El Zein & Bedjanian, 2012; H. J. Li et al., 2010; R. Li et al., 2020; C. Liu et al., 2017; Y. Liu et al., 2015; Ndour et al., 2008; Tan et al., 2016; Underwood et al., 1999; Zhang et al., 2012; Zhou et al., 2015).…”

On mineral dust aerosol hygroscopicity

“…In addition, Brunauer-Emmett-Teller (BET) surface areas of these samples were determined using an accelerated surface area and porosimetry analyzer (ASAP 2020 PLUS, Micromeritics, Georgia, USA), and N 2 was used as the adsorbate. Details on particle size and BET surface area measurements can be found elsewhere (Li et al, 2020).…”

“…Mineral dust can also change the abundance of reactive trace gases as well as aerosol compositions via heterogeneous reactions (Usher et al, 2003;Dupart et al, 2012;He et al, 2014;Tang et al, 2017;Yu and Jang, 2019). Furthermore, the deposition of mineral dust will bring substantial amounts of nutrients (e.g., Fe and P) into some marine and terrestrial ecosystems, thereby largely affecting biogeochemistry in these regions (Jickells et al, 2005;Okin et al, 2011;Schulz et al, 2012;Li et al, 2017;Tagliabue et al, 2017;Meskhidze et al, 2019).…”

On mineral dust aerosol hygroscopicity

“…In addition, Brunauer-Emmett-Teller (BET) surface areas of these samples were determined using an accelerated surface area and porosimetry analyzer (ASAP 2020 PLUS, Micromeritics, Georgia, USA), and N2 was used as the adsorbate. Details on particle size and BET surface area measurements can be found elsewhere (Li et al, 2020).…”