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 
pollutant accumulation modelling and an environmental risk assessment (see Faber et al., 2019 
in chapter 7.3). 
Ushakov et al. (2019) (in Table A-4 presented as NORW) carried out a study financed by SFI 
Smart Maritime and the Norwegian NOx-Fund. The samples were taken on board a LPG tanker 
(Clipper Harald) being at berth and operating auzxiliary engines. The ship was equipped with an 
OL-EGCS, including water treatment (residence tank and cyclonic separation), and low-pressure 
exhaust gas recirculation (EGR). The study focused on the performance evaluation of the 
application of the combined air pollution abatement technologies (EGR and EGCS) expected to 
be adopted by ships to comply with the SOx (SECA) and NOx (Tier III) requirements. Increased 
generation of particulate matter due to the application of EGR (deteriorated combustion) was 
expected and confirmed with the exhaust gas analysis, which might affect the EGCS discharge 
water composition. Water samples were taken at the inlet, after the absorption tower and after 
the water treatment; the analysis results from the latter are presented in Table A-4, Some of the 
main findings and discussions highlighted in the study are: 
bb 
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Water treatment efficiency for hydrocarbon fractions resulted in the range 45 - 55%, 
for metals around 10% and for PAHs below 15%. 
The majority of the measured PAHs are not carcinogenic. 
Only phenanthrene, fluoranthene and pyrene showed values above the Norwegian 
Environmental Quality Standards (EQS). 
For arsenic, copper, molybdenum and lead high concentrations in the inlet were 
measured, typical for high-traffic harbour areas. The concentrations of those 
compounds were actually lower (10 - 30%) in the discharge water. 
Significant enrichment of vanadium and nickel in discharge water is of high concern, 
t‘heir concentration exceeded by a factor of 26 and 5 the national EQS. These 
compounds originate from the fuel. 
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Zinc also showed an increase in discharge water and its concentration exceeded by a 
factor of 2.2 the national EQS. This compound may originate from lube oil. 
Turbidity, nitrate and pH (assuming sufficient dilution) resulted compliant to the 
{MO requirements. 
Turbidity is pointed out as a very simple and robust proxy parameter for suspended 
solids. However, its accuracy and significance are scientifically questioned due to the 
measurement uncertainties caused by organics in seawater and different sizes of 
narticulate matter. 
Nitrate and nitrite concentrations were below the detection limit. It is concluded that 
only a minor part of NOx ended up in the discharge water. 
The study reported for the first sampling campaign abnormal concentrations of copper, zinc and 
lead not explained by the fuel analysis and are probably caused by the valves and piping 
material of the sampling points. Those results were not further considered, and the components 
were replaced by stainless steel. The authors questioned the current water discharges from 
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