Bioremediation of petroleum hydrocarbons in anoxic marine sediments: consequences on the speciation of heavy metals.
We investigated the effects of biostimulation and bioagumentation strategies applied to harbor sediments displaying reducing conditions and high concentrations of petroleum hydrocarbons and heavy metals. We compared the microbial efficiency of hydrocarbon removal from sediments maintained for 60 days in anoxic conditions and inoculated with acetate, sulfate-reducing bacterial strains and acetate and sulfate-reducing bacteria. All treatments determined a significant increase in the microbial growth and significant decreases of hydrocarbon contents and of redox potential values. The addition of sulfate-reducing bacterial strains to the sediment was the most efficient treatment for the hydrocarbon removal. In all experiments, significant changes of the heavy metals' phase repartition were observed. The results reported here suggest that the biodegradation of petroleum hydrocarbons in anoxic marine sediments may be enhanced by stimulating microbial anaerobic metabolism, but care should be applied to monitor the potential changes in the mobility and bioavailability of heavy metals induced by bio-treatments.
Dell'Anno
Antonio
A
Department of Marine Science, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy. a.dellanno@univpm.it
Beolchini
Francesca
F
Gabellini
Massimo
M
Rocchetti
Laura
L
Pusceddu
Antonio
A
Danovaro
Roberto
R
D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry* / Q000382:microbiology; D006838:Hydrocarbons / Q000032:analysis / Q000378:metabolism*; D007700:Kinetics; D019216:Metals, Heavy / Q000032:analysis / Q000378:metabolism*; D010578:Petroleum / Q000032:analysis / Q000378:metabolism*; D012623:Seawater / Q000737:chemistry* / Q000382:microbiology; D013431:Sulfates / Q000378:metabolism; D014874:Water Pollutants, Chemical
D006838:Hydrocarbons; D019216:Metals, Heavy; D010578:Petroleum; D013431:Sulfates; D014874:Water Pollutants, Chemical