TEXTE Environmental Impacts of Exhaust Gas Cleaning Systems for Reduction of SOx on Ships — Analysis of status quo 
Report compiled within the framework of the project ImpEx 
other systems (e.g. engine cooling, ballast and other supporting systems) that could be possibly 
contaminated. 
Magnusson et al. (2018) (in Table A-4 presented as IVL) from the Swedish Environmental 
Research Institute (IVL) carried out a study as part of the project “Scrubber: Closing the loop” 
coordinated by Stena Teknik and funded by the EU. In this project, three ships (Stena Britannica, 
Stena Forerunner and Stena Transporter) were sampled during a sea voyage. Since those ships 
usually cover a route between Great Britain and the Netherlands, it is assumed that the sampling 
was conducted in the North Sea region. The ships included two RoPax and one RoRo vessel; two 
of them equipped with CL system and one with OL system. A particularity of this study was the 
analysis ofhydrocarbons both aliphatic and aromatic for different size fractions and eleven 
alkyl-PAHs. One of the focus of this study was to assess the removal efficiency of the bleed-off 
treatment unit (BOTU) by analysing samples taken before and after the treatment unit of a CL 
system. To this regard, the authors concluded that: 
Turbidity is reduced by 96% but still higher than the inlet seawater 
Overall reduction of total hydrocarbons was around 97%, observing higher efficiency 
in the removal of heavy fractions than the lighter ones. 
Aliphatic hydrocarbons with >C16 were removed by >99%. However, the short chains 
(>Cs8 - C12) showed a significant increase. 
Aromatic hydrocarbons with three rings or more were removed in the range 90% - 
>99%. For instance, PAHzra16 With 4-6 rings were reduced with an efficiency >99%. 
Most metals concentrations were reduced (60% - 95%). However, copper and 
mercury concentrations were higher after the treatment unit, which could not be 
explained. 
Presence of alkyl-PAHs was determined. Concentrations of the sum of the eleven measured 
alkyl-PAHs in discharge water resulted in 27 and 138 ug/L from OL and CL, respectively. Other 
important parts of this study are the ecotoxicological assays (see chapter 7.2) and the derived 
environmental risk assessment (see chapter 7.3). In addition to this study (Task 2), IVL 
published other reports focused on air emissions measurements (Task 1), cost benefit analysis 
(Task 3) and a life cycle assessment (Task 4) as part of the aforementioned project. 
EGCSA and Euroshore (2018) (in Table A-4 presented as CESA) carried out a joint sampling 
campaign on board 20 ships in the North and Baltic Sea region and two ships in the 
Mediterranean Sea to gain information about the EGCS discharge water composition from OL 
and CL systems. The sampled ships included RoRo/RoPax (11), cruise ships (3), oil tankers (3), 
vehicle carriers (2), multi-purpose (1), RoRo container (1) and container ship (1). Samples were 
taken at a point prior to any dilution and analysed for the determination of the parameters 
shown in Table A-4 and benzene, toluene, ethylbenzene and xylene (BTEX). Results were 
normalized to 45 m3/h discharge water flowrate and compared to limit values. Some of the main 
findings and discussions highlighted in the report regarding the discharge water are: 
In all samples the PAHgpa16 concentration was below 43 ug/L and average of 12 ug/L. 
Naphthalene (47%), phenanthrene (25%) and fluorene (8%) were the three 
dominant species in the PAHgpa16 composition. That is comparable to crude oil and 
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