Measuring and Modeling Organochlorine Pesticide Response to Activated Carbon Amendment in Tidal Sediment Mesocosms
Autor: | Ching-Hong Hsieh, Richard G. Luthy, Donald P. Weston, Jay M. Thompson, Thomas P. Hoelen |
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Rok vydání: | 2016 |
Předmět: |
Geologic Sediments
0208 environmental biotechnology Amendment Chlordane 02 engineering and technology 010501 environmental sciences 01 natural sciences DDT Mesocosm chemistry.chemical_compound medicine Environmental Chemistry Pesticides 0105 earth and related environmental sciences Sediment General Chemistry Pesticide Contamination Carbon 020801 environmental engineering chemistry Charcoal Environmental chemistry Particle size Activated carbon medicine.drug |
Zdroj: | Environmental Science & Technology. 50:4769-4777 |
ISSN: | 1520-5851 0013-936X |
Popis: | Activated carbon (AC) sediment amendment for hydrophobic organic contaminants (HOCs) is attracting increasing regulatory and industrial interest. However, mechanistic and well-vetted models are needed. Here, we conduct an 18 month field mesocosm trial at a site containing dichlorodiphenyltrichloroethane (DDT) and chlordane. Different AC applications were applied and, for the first time, a recently published mass transfer model was field tested under varying experimental conditions. AC treatment was effective in reducing DDT and chlordane concentration in polyethylene (PE) samplers, and contaminant extractability by Arenicola brasiliensis digestive fluids. A substantial AC particle size effect was observed. For example, chlordane concentration in PE was reduced by 93% 6 months post-treatment in the powdered AC (PAC) mesocosm, compared with 71% in the granular AC (GAC) mesocosm. Extractability of sediment-associated DDT and chlordane by A. brasiliensis digestive fluids was reduced by at least a factor of 10 in all AC treatments. The model reproduced the relative effects of varying experimental conditions (particle size, dose, mixing time) on concentrations in polyethylene passive samplers well, in most cases within 25% of experimental observations. Although uncertainties such as the effect of long-term AC fouling by organic matter remain, the study findings support the use of the model to assess long-term implications of AC amendment. |
Databáze: | OpenAIRE |
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