Sorption of polycyclic aromatic hydrocarbons and silver(I) on mineral surfaces

Setschenow constants of eight electrolytes (i.e., NaCl, KCI, CaCl ₂, K₂SO₄, Na₂SO₄, NaClO ₄, AgClO₄, and Hg(ClO₄)₂) for three polycyclic aromatic hydrocarbons (PAHs) (i.e., naphthalene, pyrene, and perylene) were quantified to evaluate the influence of variety of inorganic salts on the aqueous solubility of PAHs. The Setschenow constants of inorganic salts for the three PAHs showed a wide range of K_S values, depending on the species of salts. In general, the effect of Na+ > K+ and Cl− > ClO₄ − was shown for three PAHs. The AgClO₄ salt exhibited salting in effect for PAHs.; Solution chemistry, sorbate chemistry, and sorbent chemistry were widely investigated to find important factors that affect PAH sorption on mineral surfaces and elucidate its microscopic mechanism. pH and ionic strength had measurable effects on the sorption of pyrene to minerals with pH-dependent sites. The hydrophobicity, of the PAH, was observed to have a strong correlation with its sorption to mineral surfaces. Mineral surface area was not found to be a predominant factor controlling PAH sorption. The mineral type might be more likely to play a crucial role in controlling the PAH sorption behavior.; Interaction of pyrene with Ag(I) in solution and on mineral surfaces was investigated to elucidate the effect of sorbed Ag(I) on PAH sorption to mineral. Ag(I) ion can interact with PAH molecules, which might result from the cation-π interaction between the positive charge of Ag(I) and the rich π electrons of PAH molecules. The values, K₁ and K₂ of equilibrium constants of complexes of Ag(I)-PAHs were 2.990 and 0.378, 3.615 and 1.261, and 4.034 and 1.255, for naphthalene, pyrene, and perylene, respectively. The sorbed Ag(I) on kaolinite and vermiculite significantly enhanced pyrene sorption coefficient. The enhancement effect of sorbed Ag(I) on sorption coefficients was different for different types of minerals.