Navigating towards environmental impact assessment of shipping
Licentiate thesis, 2022
One objective within this work is to quantify the contaminant loads of metals and polycyclic aromatic hydrocarbons (PAHs), from different ship-activities with a focus on scrubbers. A scrubber is installed on ships as an abatement technique to meet the requirements stated in the new regulations of sulphur content in marine fuels. In a scrubber, the ship exhausts are led through a spray of water and SOX is easily dissolved and particles are scavenged. The scrubber system can be open (where seawater is pumped through the system continuously), closed (where water is recirculated with a small bleed-off) or hybrid (where the mode of operation can be shifted between open and closed). The scrubber technique has moved the emissions from air to water with unknown impacts.
Emission factors of metals and PAHs from usage of marine gas oils (MGOs) and heavy fuel oils (HFOs), with and without the use of scrubbers, where derived from an extensive literature review. The results show that HFO combustion with a scrubber result in much higher emission factors of metals and PAHs as compared to the use of MGO. These emission factors were then used to determine the relative load contribution from scrubbers compared to other ship-activities, coastal industries, atmospheric deposition and riverine input to the Baltic Sea. The comparison revealed that open loop scrubber discharge and release of biocides from antifouling paints are the two largest anthropogenic sources of several metals and PAHs, e.g. copper, vanadium and anthracene, to the Baltic Sea. In addition, the cumulative environmental risk assessment of 9 metals and 16 PAHs from near-ship atmospheric deposition, antifouling paint, bilge water discharge, closed and open loop scrubber water discharge) show unacceptable risk in three out of four ports.
The total contaminant load from shipping and subsequent risks of adverse effects on the marine environment can be assessed with existing tools. The use of HFO and scrubbers result in high emissions, in absolute and relative terms, of metals and PAHs to both air and water. The result suggests that the use of scrubbers cannot offer a sustainable solution and the discharge of scrubber water should be prohibited to increase the probability of achieving Good Environmental Status in the Baltic Sea.
polycyclic aromatic hydrocarbons
Anna Lunde Hermansson
Chalmers, Mechanics and Maritime Sciences (M2), Maritime Studies
Comparing emissions of polyaromatic hydrocarbons and metals from marine fuels and scrubbers
Transportation Research Part D: Transport and Environment,; Vol. 97(2021)
Metal and PAH loads from ships and boats, relative other sources, in the Baltic Sea
Marine Pollution Bulletin,; Vol. 182(2022)
Lunde Hermansson, A., Hassellöv, I.-M., Jalkanen, J.-P. & Ytreberg, E. Cumulative environmental risk assessment of metals and polycyclic aromatic hydrocarbons from ship activities in ports. Submitted to Journal of Environmental Management.
Other Environmental Engineering
Room Beta, Saga building, Campus Lindholmen, Hörselgången 4
Opponent: Olof Berglund, University of Lund, Sweden