Effects based methods (EBMs) in combination with passive sampling of refinery streams

Report no. 11/22: This report provides an overview of spot and passive sampling data of three refinery effluents after treatment that were collected for chemical and ecotoxicological effluent assessment. The report includes a discussion of the relationships between toxic units derived from spots samples and passive samplers.

Further, it discusses if the observed toxicity from the passive sampler extracts can be explained by chemical analyses and makes an overall comparison between spot and passive sampling. Return of experience on the application of passive samplers within refinery effluent assessments, including technical considerations on the use of passive vs. spot sampling are summarized. If and how passive sampling can help towards making better decisions and assessments of refinery waters is also discussed. The report concludes that passive sampling provides information on the dissolved fraction as well as a time-weighted averaged sample over several weeks, which is not provided by spot sampling.

However, there are a number of challenges when translating bioassay outcomes of the passive sampler extracts to the toxicity response of the original waters, and these challenges seem largely related to the use of partition based passive samplers. From the work conducted in this project it can be concluded that expert labs and detailed knowledge are needed to properly interpret the results from assessments that combine passive sampling studies with effect-based methods testing. Overall, this approach is not yet ready for routine monitoring but might be more suitable for targeted, location specific surveillance studies.