Suchergebnisse

Following the implementation of international regulations to reduce sulphur oxide emissions in maritime shipping, scrubbers are used on about 25 % of the world merchant fleet (measured by deadweight tonnage). In the present study, a sampling and measurement campaign was conducted on board four ships with focus on the chemical characterisation and the determination of ecotoxicological effects of scrubber discharge water. Heavy metals such as vanadium, nickel, copper, iron and zinc as well as organic pollutants, including polycyclic aromatic hydrocarbons (even beyond the ones included in the US EPA priority list) and oil residues, were found in elevated concentrations. The whole effluent toxicity of the scrubber discharge waters ranged from practically non-toxic to considerably toxic for the open loop to extremely toxic for the closed loop operation mode samples. Further, almost all samples demonstrated mutagenic and the closed loop samples, dioxin-like effects. Thus, the release of scrubber discharge water from both operation modes into the sea is of high concern. This effluent is acidic and contains persistent, bioaccumulative and toxic pollutants that may cause short- and long-term detrimental effects in the marine environment. In this regard, the current discharge criteria and regulatory measures were found to be insufficient and other protective measures for the marine environment such as local or regional discharge bans are proposed.