title: Biodegradation of UV-filters in marine sediments.
abstract: The degradation of two of the most frequently used UV-filters was investigated through microcosm studies. Marine sediments sampled from two sites in Italy (La Spezia harbour and Sarno river estuary, S1 and S2 respectively) were used to set up aerobic and anaerobic sets of reactors. The sediments were spiked with a methanol solution of 3-(4-methylbenzylidene)camphor (4-MBC) and 2-ethylhexyl 4-(dimethylamino)benzoate (EH-DPAB), at concentrations of either 25 or 50mgkg-1each. Methanol (6.3g/L) also served as an organic amendment and growth substrate for improving microbial activity. Monitoring of the biotic and abiotic degradation of the selected contaminants over 16months revealed that 4-MBC biodegradation was very slow and incomplete, whereas over 90% of EH-DPAB was degraded both in the aerobic and the anaerobic reactors by the natural microbial communities of both sediments. Repeated spikes of EH-DPAB were followed by complete decay, characterised by first-order kinetics. The calculated kinetic rate constants under aerobic and anaerobic conditions were similar. In reactors inoculated with the S1 sediment the degradation rate constants progressively increased after each spike, up to the value of 0.039d-1. For the S2 sediment the rate constant was around 0.020d-1throughout the duration of the experiment. Mass spectrometry analysis of sediment extracts allowed detection of potential transformation products of EH-DPAB and 4-MBC. Moreover, the natural microbial community of the sediments was studied using the CAtalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD-FISH) both in the initial sediments and after degradation under aerobic and anaerobic conditions.
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto di Ricerca Sulle Acque (CNR-IRSA) Viale F. De Blasio, 5 - 70132 Bari, Italy. Electronic address: angela.volpe@ba.irsa.cnr.it.
authors.forename: Angela
authors.initials: A
authors.lastname: Volpe
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto di Ricerca Sulle Acque (CNR-IRSA) Viale F. De Blasio, 5 - 70132 Bari, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Pagano
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto di Ricerca Sulle Acque (CNR-IRSA) Viale F. De Blasio, 5 - 70132 Bari, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Mascolo
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto di Ricerca Sulle Acque (CNR-IRSA), Via Salaria Km. 29, 300 - 00015 Monterotondo, RM, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Grenni
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto di Ricerca Sulle Acque (CNR-IRSA), Via Salaria Km. 29, 300 - 00015 Monterotondo, RM, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Rossetti
keywords: Biodegradation; CARD-FISH; Marine sediments; Microcosms; UV-filters