Lookup NU author(s): Professor David Werner,
Professor Richard Luthy
This is the authors' accepted manuscript of an article that has been published in its final definitive form by John Wiley & Sons, Inc., 2018.
For re-use rights please refer to the publisher's terms and conditions.
We evaluated bioturbation as a facilitator for in-situ treatment with a thin-layer of activated carbon (AC) to treat dichlorodiphenyltrichloroethane (DDT)-contaminated sediment and contaminant influx by sediment deposition. Using the freshwater worm, Lumbriculus variegatusas a bioturbator, microcosm time-series studies were conducted for four months and monitored for DDT flux and porewater concentration profiles by passive samplers. With bioturbators present, the thin-layer AC amendment reduced DDT flux by >90% compared to the same simulated scenario without AC amendment. In contrast, a clean sediment cap without AC was ineffective in reducing flux when bioturbation was present. In simulated scenarios with contaminant influx through deposition of contaminated sediment, bioturbation facilitated in-situ AC treatment, reducing 4-month DDT flux by 77% compared to the same scenario without bioturbation. Porewater concentration profiles and AC dose profiles confirmed effective mixing of AC particles down to 1 cm depth. A mass transfer model was developed to predict flux with consideration of bioturbation and sediment deposition processes. Predicted flux values were consistent with experimental results and confirm that bioturbation activity helps reduce DDT sediment-to-water fluxes in AC-treated sediment with recontamination by contaminated sediment deposition. This is the first study to developed combined experimental and modeling results showing how bioturbation enhances AC amendment effectiveness against ongoing contaminant influx by sediment deposition.
Author(s): Lin D, Cho YM, Tommerdahl JP, Werner D, Luthy RG
Publication type: Article
Publication status: Published
Journal: Environmental Toxicology and Chemistry
Print publication date: 01/07/2018
Online publication date: 09/03/2018
Acceptance date: 05/03/2018
Date deposited: 05/04/2018
ISSN (print): 0730-7268
ISSN (electronic): 1552-8618
Publisher: John Wiley & Sons, Inc.
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