PARENT SESSION
TA6 - Bioavailability Issues in Bioremediation of Contaminated Sediments
Chair: Tabak, Henry1, 1 U.S. EPA, Cincinnati, OH
Co-chair: Lazorchak, Jim2, 2 U.S. EPA, Cincinnati, OH
8:00 AM to 12:00 PM - Tuesday, 19 November 2002
Room Ballroom B
(381) A Toxicity Assessment Approach for Evaluation of PAH Contaminated Sediments.
Tabak, Henry*,1, Lazorchak, James2, Smith, Mark3, Ferreti, James, 1 USEPA, NRMRL, ORD, 26 W. Martin Luther King Drive, Cincinnati, OH, USA2 USEPA, NERL, ORD, 26 W. Martin Luther King Drive, Cincinnati, OH, USA3 SoBran, Inc. 26 W. Martin Luther King Drive, Cincinnati, OH, USA
ABSTRACT- Freshwater and marine sediment toxicity tests were used to measure baseline toxicity of sediment samples collected from New York/New Jersey Harbor (NY/NJH) (with traces of PAHs) and East River (ER) (PAH contaminated) sediments and to determine the effectiveness of the developed biotreatment strategies in reducing ecotoxicity of the contaminated sediments. Four freshwater toxicity tests using amphipods, aquatic worms, fathead minnow larvae and a vascular plant,(Duckweed) and two marine tests using a marine amphipod and sheepshead minnow larvae,were employed in the study. To determine the cause of toxicity in these sediments, five sediment manipulations were performed: a sediment purge procedure, a sediment aeration procedure; Ambersorbs 563 and 572 resin treatment procedure for removal of organics and an Amberlite IRC-718 resin treatment procedure for removal of inorganics (metals). ER sediment was found to be highly toxic to all freshwater and marine organisms tested while the NY/NJH sediment showed no significant toxicity to the marine amphipod but was slightly toxic to the freshware worm and to freshwater and marine fish larvae. For all tests ran on ER sediment with the freshwater organisms and the one marine amphipod, no survival was found.. The ER sediment significantly reduced frond production (58.3%) and chlorophyl a levels (35.4%) in the freshwater duckweed test. Results from the five sediment manipulation studies showed that freshwater amphipod survival was improved with sediment aeration procedure, with 8% 563 and 572 as well as with IRC-718 treatments. Toxicity can also be reduced with the sediment dilution techique (100 fold) .These manipulations and analyses for the specific inorganic and organic contaminants revealed that hydrogen sulfide, PAHs and metals were factors in ER sediment toxicity. Results from Hyalella azteca toxicity tests using ER and NY/NJH sediments treated by aerobic biodegradation slurry approaches showed reductions in toxicity to H. azteca equal to or greater than that achieved through chemical or mechanical manipulations of the sediment samples. H. azteca survival after various aerobic bioslurry treatments of ER sediment ranged from 35% to 65%, compared to survival of 20% in ER sediment tested by aeration and addition of 8% 572 resin.
Key words: toxicity assessment of sediments, PAH contaminated sediments, bioremediation, toxicity impacting bioremediation