Source identification of marine water pollution from highly viscous persistent floaters with a focus on paraffin waxes
In June 2016, the BSH project for the investigation of oiled birds and oil contamination on beaches was very successfully completed. This project provided new insights into the composition and relevance of different types of water and beach contamination. This led to a re-evaluation of previously predominant pollution types (oil) and substances with currently increasing inputs (such as paraffin wax) into the marine environment. The increasing relevance of this issue requires sustainable marine management. In the VERIFY project (April 2017 - March 2019) (identification of polluters in marine waters by highly viscous persistent floating products with a focus on paraffins), the BSH investigated possibilities for environmental forensic fingerprinting, a tool to characterize these novel marine pollutants. This allows the successful identification of polluters in a (paraffin) spill event.
Worldwide, paraffin waxes are transported as liquid bulk cargo in heated tankers and are released into the marine environment due to currently (still) permitted tank-washing. Paraffin waxes are floating petroleum products. The number of transports and the subsequent discharges of washing water are constantly increasing. These current developments are perceived and discussed at international level by the International Maritime Organisation (IMO). Therefore, many littoral states endeavour a stronger restriction or ban for the discharge of such substances into the marine environment in the future.
To ensure such a restriction or ban, reliable analytical methods must be developed for the successful identification of polluters.
- Identification of input pathways and quantities of paraffin waxes into the marine environment,
Detailed chemical-analytical characterisation of the paraffin waxes washed up on the beach. Comparison of these spill samples with reference cargo samples.
- Identification of specific substance characteristics (markers) for the reliable identification of possible ship cargoes,
- Development of appropriate chemical-analytical methods,
- Extension of the substance database and development of statistical methods.
Methods for evaluating paraffin composition
- Gas chromatography (GC) coupled with flame ionization detection (FID) or mass spectrometry (MS) (substance identification and purity determination),
- High performance thin layer chromatography (HPTLC),
- Headspace (HS) analysis with/without enrichment by solid phase micro extraction (SPME- or HS-GC-MS/MS),
- Differentiation of very small samples of plastic or paraffin using infrared spectroscopy (IR).
The project did not succeed in finding a single analytical method for the reliable identification of paraffin waxes and other highly viscous floaters in order to achieve robust final decisions in the comparisons of spill and source samples. This is primarily due to the fact that no specific markers could be identified that would allow a detailed and distinct characterisation.
On the basis of the current state of knowledge, it seems advisable to choose a combination of the methodologies presented in the project in order to establish a procedure for source identification of spills. By using information from different analytical approaches, it might be possible to develop and establish a procedure for paraffin (and other floaters) spill identification according to the model of CEN/TR 15522-2:2012.