Biological degradation of UV-filters in marine sediments: A laboratory microcosm study

The biodegradation potential of marine sediments towards two selected UV-filters was tested through a laboratory investigation. Sediments collected from two locations in Italy were spiked with 3-(4-methylbenzylidene)camphor (4-MBC) and 2-ethylhexyl 4-(dimethylamino)benzoate (EH-DPAB), and used to set up eight microcosms that were operated under either aerobic or anaerobic conditions. UV-filters concentration in the sediment was monitored over 360 days. Results showed that native microbial communities of both sediments were able to perform the complete removal of EH-DPAB, whereas 4-MBC was scarcely affected by biodegradation. Degradation kinetics of EH-DPAB was first-order, with kinetic rate constants around 0.02 d-1 for both sediments under both aerobic and anaerobic conditions. Microbiological characterisation of microcosms showed that the composition and structure of the sediment microbial communities changed after the different treatments with respect to the native microbial population.