Particle size distribution of organic compounds in aqueous aerosols collected from above sewage aeration tanks

Several classes of organic compounds were analyzed in aqueous aerosols coll ected in June, November, and December 1996 from above the sewage aeration t anks of a treatment plant (Prato, Italy), Particle size distribution of org anic compounds and their enrichment ratio (E-r) with respect to the magnesi um ion were determined to infer the extent to which various species were ae rosolized, Organic components were found to be predominantly enriched in fi ne and large particles of the aerosol and their transfer may be attributed to the 1) adsorption of surfactant organic matter at the air/water interfac e (such phenomenon is particularly evident for the fine and ultra-fine frac tions) and 2) flotation of colloidal matter from wastewater to the largest particles with consequent transport of the adsorbed organic compounds. In a ddition, the interaction of surfactants with hydrophobic compounds explaine d the enrichment of the latter in the finest fractions.