Συμπεριφορά φεναθρίνης σε κυπριακά εδάφη κάτω από εργαστηριακές συνθήκες

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds that consist of two or more fused benzene rings in linear or branched position. The PAH who was used in this thesis is phenanthrene (PHE). Phenanthrene belongs to the 16 PAHs, which have been identified as priority pollutants by the Environmental Protection Agency of the USA. PAH, are among the most important environmental contaminants because of their reactivity with the environment and biota. They are mainly formed by incomplete combustion or pyrolytic processes with high temperature (500-900 ° C) fossil fuels and other organic pollutants. PAHs, end up in soil, through wet and dry deposition, by spreading oil residues and direct from combustion activities. The concentration in the soil depends on their physicochemical properties, such as low water solubility and high octanol water coefficients, which makes them more recalcitrant in the environment. Phenanthene was introduced to the soil at an concentration of at regular intervals, samples of contaminated soil in triplicate were extracted usign, using three solvents. The solvents used were calcium chloride, the solvent (A, CaCl2, 0.02 M), solvent methanol:water (B, 9:1) and the solvent acetone (C). Then, subsamples of solvents A, B and C, were placed in the gas chromatograph for analysis and detection of extracted Phenanthere concentration. The results indicated that there was a significant decrease in the concentration of PHE released from the soil during the course of the sampling campaign (1,7,18, 30, 40 days), and this is due to sequestration of contaminant in soil matrix. The extraction by solvent A (Solution CaCl2, 0,02M), showed no significant extraction of PHE concentration. This is may be attributed to the polar nature of the solvent. Through the extraction with solvent B (Solution methanol: water [9:1]), appears that in to soil K the concentration of PHE decreases to higher extent than the soil P. Comparing the behavior of the two soils, when in presence of solvent C they appear to react completely different, since the concentration of the soil P PHE although initially reduced in the end seems to have the same value with the value of the initial concentration of the PHE was introduced in the soil. This result may be due to the accumulation of pollutant in a specified point (hot spots) in soil. While the soil S, the value of the final concentration of PHE in soil seems to be reduced to higher extent, since the amount pollutant is extracted more. Comparing the PHE extracted concentrations ix it appears that the solvent B offers greater extractability of PHE in soil P.In the case of soil K, solvent C shows better extractability of PHE.