Idrocarburi Policiclici aromatici nei sedimenti marini superficiali antistanti la centrale termoelettrica di Cerano - BR (Adriatico meridionale)

ItÈ stata effettuata un’indagine per valutare la presenza e la quantità degli IPA nei sedimenti prospicienti la Centrale ENEL di Cerano. Gli IPA derivano soprattutto da processi di combustione, tendono a legarsi al particolato e ad accumularsi nei sedimenti.Gli IPA riscontrati in quest’indagine presentano concentrazioni comprese fra 7,2 e 797,0 µg/Kg. Nel complesso i valori di IPA sono paragonabili a quelli di aree marine in cui c’è presenza di insediamenti industriali. Le stazioni più contaminate sono quelle a maggiore distanza dalla Centrale, a circa mezzo miglio, probabilmente perché i sedimenti sono sospinti dalla corrente marina in direzione S-E.EnThe survey was carried out in the 1999 and the PAH contamination of Adriatic Sea sediments was evaluated. Twenty-three samples were collected, opposite to power station of Cerano, in the same stations of previous investigation in 1992.The power station of Cerano had begun the activity in 1991.From 1996 the power station had used “Orimulsion” fuel, that is emulsioned bitumen in water. To cool the capacitors of the power station, the sea water was used.After washing of the capacitors and after saturation of the smokes, the sea water was treated before discharged in the marine enviroment.The samples were collected using the sediment corer, frozen at 4 °C and the PAH were determinated by gas chromatography in the fine sediment fraction (i.e. the one with particulate diameter < 0,63 µm). Twelve PAH compounds were identified. The concentrations of the most part of identified compounds were moderately low and similar to natural values. The concentration of chrysene, naphthalene and fluorene were higher than natural values in three stations. Benzo(a)anthracene and dibenzo(a,h)anthracene, compounds reported to be carcinogenic, were moderately higher in two stations.The PAH concentration varied from 7,2 µg/Kg to 797,0 µg/Kg of dry sediment. The higher concentrations of PAH were found in ten stations.Four stations showed higher values of total PAH than previous survey, that had considered the Adriatic sea sediment moderately contaminated by PAH, in comparison with other marine sediments.The stations less contaminated by PAH were found near power station, whereas those more contaminated were found further power station, about 0,5 miles. It occurred because the fine fraction of sediments was shifted offshore by marine currents