Polycyclic aromatic compounds including non-target and 71 target polycyclic aromatic hydrocarbons in scrubber discharge water and their environmental impact.

Increasing use of scrubbers on vessels for reduction of SOx emissions has led to environmental concerns due to discharge of partly persistent and toxic substances such as polycyclic aromatic compounds (PAC) into the sea. A comprehensive analysis of the dissolved and particulate phases of the discharge water from open and closed loop operations on four ships was performed. 71 PAC in the discharge waters varied in concentration and were associated with those of the fuels used, as they mainly originate in unburnt fuel. Closed loop discharge water showed higher PAC concentrations, especially of HMW PAC, which partly explains the larger toxic effects reported for this discharge. Alkylnaphthalenes and -phenanthrenes dominated in dissolved and particulate fractions, respectively. 14 NSO-PAC concentrations were relatively low. Alkylated derivatives of 4H-cyclopenta[4,5-def]phenanthrene and/or phenylnaphthalene were for the first time tentatively identified using GC-APLI-MS. The use of low-PAC fuels could significantly reduce PAC ship emissions.