A Laboratory Case Study of Efficient Polyhydoxyalkonates Production by Bacillus cereus, a Contaminant in Saccharophagus degradans ATCC 43961 in Minimal Sea Salt Media

2014 ◽  
Vol 69 (6) ◽  
pp. 832-838 ◽  
Author(s):  
Shailesh S. Sawant ◽  
Bipinchandra K. Salunke ◽  
Beom Soo Kim
Keyword(s):  
Bacillus Cereus ◽  
Sea Salt ◽  
Saccharophagus Degradans

scholarly journals Sea salt emission, transportation and influence on nitrate simulation: a case study in Europe

2016 ◽  
Author(s):  
Ying Chen ◽  
Yafang Cheng ◽  
Nan Ma ◽  
Ralf Wolke ◽  
Stephan Nordmann ◽  
...  
Keyword(s):  
Surface Wind ◽  
Global Scale ◽  
Sea Salt ◽  
Wind Pattern ◽  
Sea Salt Aerosol ◽  
Coarse Mode ◽  
Significant Difference ◽  
Fine Mode ◽  
Inorganic Aerosol

Abstract. Sea salt aerosol (SSA) is one of the major components of primary aerosols and has significant impact on the formation of secondary inorganic aerosol particles on a global scale. In this study, the fully online coupled WRF-Chem model was utilized to evaluate the SSA emission scheme and its influence on the nitrate simulation in a case study in Europe during September 10–20, 2013. Meteorological conditions near the surface, wind pattern, and thermal stratification structure were well reproduced by the model. Nonetheless, coarse mode (PM1–10) particle mass concentration was substantially overestimated due to the overestimation of SSA and nitrate. Compared to filter measurements at 4 EMEP stations (coastal stations: Bilthoven, Kollumerwaard and Vredepeel; inland station: Melpitz), the modeled SSA concentrations were overestimated by a factor of 8–20. We found that the overestimation was mainly caused by the overestimated SSA emission over North Sea during September 16–20. Over the coastal regions, the SSA was injected into the continental free troposphere through an “aloft bridge” (about 500 to 1000 meter above the ground), a result of the different thermodynamic properties and planetary boundary layer (PBL) structure between continental and marine regions. The injected SSA was further transported inland and mixed downward to the surface through downdraft and PBL turbulence. This process broadened the influence of SSA to a larger downwind region, for example, leading to an overestimation of SSA at Melpitz, Germany by a factor of ~20. As a result, nitrate partitioning fraction (ratio between particulate nitrate and the summation of particulate nitrate and gas-phase nitric acid) increased by about 0.2 for the coarse mode nitrate due to the overestimation of SSA at Melpitz, but no significant difference in the partitioning fraction for the fine mode nitrate. About 140 % overestimation of the coarse mode nitrate was resulted from the influence of SSA at Melpitz. On the other hand, the overestimation of SSA inhibited the nitrate formation in the fine mode by about 20 %, because of the increased consumption of precursors by coarse mode nitrate formation.

scholarly journals Sea salt emission, transport and influence on size-segregated nitrate simulation: a case study in northwestern Europe by WRF-Chem

2016 ◽  
Vol 16 (18) ◽  
pp. 12081-12097 ◽  
Author(s):  
Ying Chen ◽  
Yafang Cheng ◽  
Nan Ma ◽  
Ralf Wolke ◽  
Stephan Nordmann ◽  
...  
Keyword(s):  
Surface Wind ◽  
Global Scale ◽  
Sea Salt ◽  
Inorganic Particles ◽  
The North ◽  
Coarse Mode ◽  
Significant Difference ◽  
The North Sea ◽  
Fine Mode

Abstract. Sea salt aerosol (SSA) is one of the major components of primary aerosols and has significant impact on the formation of secondary inorganic particles mass on a global scale. In this study, the fully online coupled WRF-Chem model was utilized to evaluate the SSA emission scheme and its influence on the nitrate simulation in a case study in Europe during 10–20 September 2013. Meteorological conditions near the surface, wind pattern and thermal stratification structure were well reproduced by the model. Nonetheless, the coarse-mode (PM1 − 10) particle mass concentration was substantially overestimated due to the overestimation of SSA and nitrate. Compared to filter measurements at four EMEP stations (coastal stations: Bilthoven, Kollumerwaard and Vredepeel; inland station: Melpitz), the model overestimated SSA concentrations by a factor of 8–20. We found that this overestimation was mainly caused by overestimated SSA emissions over the North Sea during 16–20 September. Over the coastal regions, SSA was injected into the continental free troposphere through an “aloft bridge” (about 500 to 1000 m above the ground), a result of the different thermodynamic properties and planetary boundary layer (PBL) structure between continental and marine regions. The injected SSA was further transported inland and mixed downward to the surface through downdraft and PBL turbulence. This process extended the influence of SSA to a larger downwind region, leading, for example, to an overestimation of SSA at Melpitz, Germany, by a factor of  ∼  20. As a result, the nitrate partitioning fraction (ratio between particulate nitrate and the summation of particulate nitrate and gas-phase nitric acid) increased by about 20 % for the coarse-mode nitrate due to the overestimation of SSA at Melpitz. However, no significant difference in the partitioning fraction for the fine-mode nitrate was found. About 140 % overestimation of the coarse-mode nitrate resulted from the influence of SSA at Melpitz. In contrast, the overestimation of SSA inhibited the nitrate particle formation in the fine mode by about 20 % because of the increased consumption of precursor by coarse-mode nitrate formation.

scholarly journals Source Apportionment of Aerosol at a Coastal Site and Relationships with Precipitation Chemistry: A Case Study over the Southeast United States

Atmosphere ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1212
Author(s):  
Andrea F. Corral ◽  
Hossein Dadashazar ◽  
Connor Stahl ◽  
Eva-Lou Edwards ◽  
Paquita Zuidema ◽  
...  
Keyword(s):  
Precipitation Chemistry ◽  
Sea Salt ◽  
Strongly Correlated ◽  
Southeast United States ◽  
Deposition Fluxes ◽  
Pmf Model ◽  
Surface Data ◽  
Southern Florida

This study focuses on the long-term aerosol and precipitation chemistry measurements from colocated monitoring sites in Southern Florida between 2013 and 2018. A positive matrix factorization (PMF) model identified six potential emission sources impacting the study area. The PMF model solution yielded the following source concentration profiles: (i) combustion; (ii) fresh sea salt; (iii) aged sea salt; (iv) secondary sulfate; (v) shipping emissions; and (vi) dust. Based on these results, concentration-weighted trajectory maps were developed to identify sources contributing to the PMF factors. Monthly mean precipitation pH values ranged from 4.98 to 5.58, being positively related to crustal species and negatively related to SO42−. Sea salt dominated wet deposition volume-weighted concentrations year-round without much variability in its mass fraction in contrast to stronger seasonal changes in PM2.5 composition where fresh sea salt was far less influential. The highest mean annual deposition fluxes were attributed to Cl−, NO3−, SO42−, and Na+ between April and October. Nitrate is strongly correlated with dust constituents (unlike sea salt) in precipitation samples, indicative of efficient partitioning to dust. Interrelationships between precipitation chemistry and aerosol species based on long-term surface data provide insight into aerosol–cloud–precipitation interactions.

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