engleski

Analysis of polycyclic aromatic hydrocarbons on upper course of the Drava River

Polycyclic aromatic hydrocarbons (PAH) are a large group of organic compounds consisting of two or more fused aromatic rings. They are lipophilic compounds, which means that they are less soluble in water, and their behavior in water depends on various physicochemical parameters. Although hundreds of PAHs exist, 16 of them are listed as priority pollutants - naphthalene, acenaphthylene, acenaphthene, anthracene, fluorene, phenanthrene, fluoranthene, chrysene, pyrene, benz[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1, 2, 3-cd] pyrene, benzo[g, h, i]perylene, and dibenz[a, h]anthracene. Naturally, they occur during volcanic eruptions and forest fires, and the production itself depends on meteorological conditions such as wind, humidity, temperature and moisture content, type of wood, changes in wood through the seasons, etc. However, their presence in the environment is primarily due to anthropogenic activities. In the last 50 years, the increase of the population and human activity caused an increase in the concentration of PAHs which are easily produced as a consequence of incomplete combustion of wood, coal, gas, oil and other fuel sources composed of carbon compounds. Smaller, low-molecular-weight PAHs (two and three rings) appear in the atmosphere mainly in the vapour phase, while larger, multi-ringed PAHs (five rings or more) are mainly bound to particles. PAHs can enter surface waters due to the discharge of untreated wastewater and municipal water or through precipitation. They stay in the environment for a long time due to their inertness and chemical stability. Since PAHs have toxic and carcinogenic effect, both in humans and animals, elevated concentrations of these compounds raise health concerns. For that reason, monitoring of the PAHs concentrations in surface waters is very important. The PAH analysis was performed at various locations on the Drava river in the north-western part of Croatia and includes the lower peripheral channel of the Čakovec hydropower plant ; Štefanec, Melačka, and Vularija bayou. The use of gas chromatography with the mass spectrometry method enabled the detection of very low concentrations of PAH. The results indicate a PAH concentration that does not exceed the maximum allowable values, with small oscillations in the concentrations. Although the water quality of the covered sites is currently satisfactory, it is necessary to monitor PAH concentrations in surface waters.

polycyclic aromatic hydrocarbons, chromatography, mass spectrometry, surface water, pollution

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