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 
Cumulative or even synergetic toxicity effects in the EGCS discharge water. This implies 
that the joint effect of the mixture of all components in the discharged water is larger 
than the effect of the individual components, also known as “cocktail effect”. 
DD 
Both, adverse and stimulating response were observed in different types of organisms. This 
proves the different sensibility of organisms and implies species-specific responses to EGCS 
discharge water: 
» Algal growth was stimulated or not affected during exposure to EGCS discharge water. 
Acute effects on luminescent bacteria were reported; while in a mesocosm experiment 
an increase in total bacterial biomass was observed. 
Fish, crustacean and copepod species showed some mortality at specific exposure 
concentrations. 
D- 
Mussels showed only effects on byssus strength. 
Different views regarding the effects of the pH of the observed toxicity effects are found in 
the studies. Low dissolved oxygen concentration is also mentioned as a toxicity factor. Both 
parameters might reach normal values immediately after dilution with surrounding water. 
To our knowledge, fish egg tests have not yet been conducted. This assay is typically 
conducted in Germany for the control and monitoring of industrial water discharges. The 
German Wastewater Directive (AbwV) Annex 47 “Scrubbing of flue gases from combustion 
plants” specifies a limit value for toxicity on fish eggs (Gsi = 2) as requirement for washing 
water discharges. 
7.4.4 Environmental risk assessment 
From the review of previous studies focused on the environmental risk assessment of EGCS 
discharge water, it is observed that the conclusions are different and even opposing. Those 
differences could be explained by: 
> the approach and methodology applied, 
> considerations for determining PEC values and 
» selected safety factors to establish PNEC values. 
7.5 Current parallel projects covering EGCS discharge water 
Four current research projects with the focus on EGCS discharge water were identified, where 
similar activities and analyses to those of the ImpEx project are planned. Therefore, contact with 
the project team members of these projects has already been established in order to exchange 
knowledge, experiences and results and thus to generate synergy effects. Further details about 
EMERGE, SAARUS, ShipTRASE, a Swedish project and ImpEx are exhibited in Table 6. 
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