title: Comparing different methods for assessing contaminant bioavailability during sediment remediation.
abstract: Sediment contamination by persistent organic pollutants from historical episodes is widespread and remediation is often needed to clean up severely contaminated sites. Measuring contaminant bioavailability in a before-and-after manner lends to improved assessment of remediation effectiveness. However, a number of bioavailability measurement methods have been developed, posing a challenge in method selection for practitioners. In this study, three different bioavailability measurement methods, i.e., solid phase microextraction (SPME), Tenax desorption, and isotope dilution method (IDM), were compared in evaluating changes in bioavailability of DDT and its degradates in sediment following simulated remediation treatments. When compared to the unamended sediments, all three methods predicted essentially the same degrees of changes in bioavailability after amendment with activated carbon, charcoal or sand. After normalizing over the unamended control, measurements by different methods were linearly correlated with each other, with slopes close to 1. The same observation was further made with a Superfund site marine sediment. This finding suggests that different methods may be used in evaluating remediation efficiency. However, Tenax desorption or IDM consistently offered better sensitivity than SPME in detecting bioavailability changes. Results from this study highlight the value of considering bioavailability when evaluating remediation effectiveness and provide guidance on the selection of bioavailability measurement methods in such assessments.
authors: Department of Environmental Sciences, University of California, Riverside, CA 92521, USA. Electronic address: fang.jia@bayer.com.
authors: Fang
authors: F
authors: Jia
authors: Department of Environmental Sciences, University of California, Riverside, CA 92521, USA.
authors: Chunyang
authors: C
authors: Liao
authors: Department of Environmental Sciences, University of California, Riverside, CA 92521, USA.
authors: Jiaying
authors: J
authors: Xue
authors: Department of Environmental Sciences, University of California, Riverside, CA 92521, USA.
authors: Allison
authors: A
authors: Taylor
authors: Department of Environmental Sciences, University of California, Riverside, CA 92521, USA.
authors: Jay
authors: J
authors: Gan
mesh_terms: D001682:Biological Availability; D002606:Charcoal / Q000737:chemistry; D003634:DDT / Q000032:analysis*; D003633:Dichlorodiphenyl Dichloroethylene / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D052918:Environmental Restoration and Remediation; D019015:Geologic Sediments / Q000737:chemistry*; D057230:Limit of Detection; D008962:Models, Theoretical; D011108:Polymers / Q000737:chemistry; D052617:Solid Phase Microextraction; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D011108:Polymers; D014874:Water Pollutants, Chemical; D002606:Charcoal; C010514:tenax; D003633:Dichlorodiphenyl Dichloroethylene; D003634:DDT
keywords: Bioavailability; Black carbon; Isotope dilution method (IDM); Remediation; Solid phase microextraction (SPME); Tenax desorption