Geochemical behaviour of PM10 aerosol constituents under the influence of succeeding anticyclonic/cyclonic situations: case of Sfax City, southern Tunisia

Abstract

The present study investigates the geochemical behaviour of PM10 aerosol constituents (Cl, Na, Si, Al, Ca, Fe, Mg, Mn, Pb, Zn, S) at Sfax City (Tunisia) under succeeding meteorological conditions, including short-lived anticyclonic, cyclonic and prolonged anticyclonic situations. The results revealed daily total concentrations fluctuating between 4.07 and 88.51 μg/m(3). The highest level recorded was noted to occur under the effect of the short-lived anticyclonic situation characterized by low wind speeds. It was 1.5 times higher than those recorded during cyclonic and long-lived anticyclonic situations characterized by moderate to high wind speeds. During the cyclonic situation, the marked increase of (Na and Cl) concentrations is associated with relatively high sea wind speeds (6 to 9 m/s), which are in turn responsible for a slight increase of crustal elements such as Al, Ca, Si, Fe and Mg, by the entrainment in the air of dust from roads and undeveloped areas. During the two anticyclonic situations, the simultaneous increase (due to communal transport) of crustal (Ca, Si, Al, Fe, Mg) and man-made (Mn, S, Pb, Zn) elements was noted to be associated with the dominance of terrigenious wind flows with speeds varying between 1.5 and 4 m/s. However, the significant contribution rates observed for Cl under the prevalence of such winds as compared to other crustal elements such as Fe suggested the influence of the sebkhas of Southern Tunisia.

Dust Particle Deposition Quality Assessment in Rural Areas Located Not Far From a Congested Highway and Several Sebkhas: Case of Monastir Region, Eastern Tunisia

“…At site S23, their importance is possibly related to the phenomenon of road dust resuspension. This result has already been proved by Bahloul et al (2015b). The temporal evolution of the particulate deposits constituents at the two sites S14 and S23 also shows a great fluctuation (Tables 3 and 4).…”

“…The marked frequency of relatively high wind speeds exceeding 7 m/s (25% of the total observations) in the Monastir region could reinforce this phenomenon. Bahloul et al (2015b) showed that velocities greater than 7 m/s significantly accentuate Regressions between mean sea level pressure and biweekly flow deposits trough the two studied sites (S14 and S23) the phenomenon of dust resuspension. The relatively high velocities normally promote the dilution of air components (including suspended particulate matter).…”

“…Such approaches have already been published in Bahloul et al (2015b). They are based on the use of the following formulae (4 and 5):…”

“…The geochemical behaviour of particulate atmospheric deposition depends on the emission sources (natural and anthropogenic) as well as the local and regional or even synoptic meteorology (wind, cyclonic or anticyclone situations, precipitation, etc.) (Azri, Chaabane, & Medhioub, 2009a;Bahloul et al, 2015b). It also depends on the physicochemical transformations to which the particles are subjected during their atmospheric transport and the characteristics of the receiving environments (Shahin, Lu, Yi, Paode, & Holsen, 2000;Cindoruk & Tasdemir, 2007).…”

Influence of Phosphorus-Contaminated Sediments in the Abundance of Potentially Toxic Phytoplankton Along the Sfax Coasts (Gulf of Gabes, Tunisia)

“…This area is marked by the presence of the SIAPE industry (Industrial Society of Phosphoric Acid and Fertilizers), which has released large amounts of phosphogypsum wastes for 40 years. These phosphogypsum wastes are a significant source of phosphates, chloride and sulphates for seawater and may explain the high chemical oxygen demand in the surface waters of Sfax (Bahloul et al, 2015;Drira et al, 2016). Besides the SIAPE industry and its phosphogypsum wastes, the Sfax coasts comprises several industrial areas related to textiles, tanneries, salt, olive oil, food processing, construction materials, ceramics and glass.…”