SPATIO-TEMPORAL DEPOSITION FLUXES OF DUST AND TRACE ELEMENTS AROUND A CEMENT PLANT IN THE VICINITY OF HAMMA BOUZIANE, ALGERIA

摘要

Particle deposition rates were measured using a network of nine gauges installed at different locations around a cement plant located south of the city of Constantine and close to the town of Hamma Bouziane from September 2002 to April 2003. Samples were collected at 30-day intervals. Pb, Cr, Mn, Ni, Cu, Co and Cd deposition fluxes were determined in dust fall. The results obtained show that the deposition rates of particles and most of the heavy metals exceed by far the international standards. The daily mean particle deposition rates varied from 518 to 1344 mg m~(-2) day~(-1) around the cement plant, exceeding everywhere the German "TA Luft" annual average of 350 mg m~(-2) day~(-1). The monitoring network allowed determining the effect of the land surface roughness, the presence of other pollution sources and wind frequency distribution. The average wind speed was much higher from September to November 2002, thus leading to high dust loadings. However, the month of December was characterized by significant rainfall which minimized dust deposition. The total dust deposition fluxes were much lower from January to April due to much lower average wind speeds. Modelling of total deposition rates of particles using ISCST3 software allowed the estimation of dust deposition attributable to the plant.