title: Predicted effectiveness of in-situ activated carbon amendment for field sediment sites with variable site- and compound-specific characteristics.
abstract: A growing body of evidence shows that the effectiveness of in-situ activated carbon (AC) amendment to treat hydrophobic organic contaminants (HOCs) in sediments can be reliably predicted using a mass transfer modeling approach. This study analyzes available field data for characterizing AC-sediment distribution after mechanical mixing of AC into sediment. Those distributions are used to develop an HOC mass transfer model that accounts for plausible heterogeneities resulting from mixing of AC into sediment. The model is applied to ten field sites in the U.S. and Europe with 2-3 representative HOCs from each site using site- and HOC-specific model parameters collected from the literature. The model predicts that the AC amendment reduces the pore-water HOC concentrations by more than 95% fifteen years after AC deployment for 18 of the 25 total simulated cases when the AC is applied at doses of 1.5 times sediment total organic carbon content with an upper limit of 5 dry wt%. The predicted effectiveness shows negative correlation with the HOC octanol-water partitioning coefficients and the sediment-water distribution coefficients, and positive correlation with the effectiveness calculated based on equilibrium coefficients of sediment and AC, suggesting the possibility for use of the values for screening-level assessments.
authors.affiliation: Department of Civil and Environmental Engineering, Seoul National University, Seoul 151-744, South Korea. Electronic address: ychoi81@snu.ac.kr.
authors.forename: Yongju
authors.initials: Y
authors.lastname: Choi
authors.affiliation: Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, USA.
authors.forename: Yeo-Myoung
authors.initials: YM
authors.lastname: Cho
authors.affiliation: Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, USA.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Luthy
authors.affiliation: School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Werner
keywords: Activated carbon amendment; Hydrophobic organic contaminants; In-situ treatment; Mass transfer model; Sediment remediation