title: Mixing and capping techniques for activated carbon based sediment remediation - Efficiency and adverse effects for Lumbriculus variegatus.
abstract: Activated carbon (AC) has been proven to be highly effective for the in-situ remediation of sediments contaminated with a wide range of hydrophobic organic contaminants (HOCs). However, adverse biological effects, especially to benthic organisms, can accompany this promising remediation potential. In this study, we compare both the remediation potential and the biological effects of several AC materials for two application methods: mixing with sediment (MIX) at doses of 0.1 and 1.0% based on sediment dw and thin layer capping (TLC) with 0.6 and 1.2 kg AC/m2. Significant dose dependent reductions in PCB bioaccumulation in Lumbriculus variegatus of 35-93% in MIX treatments were observed. Contaminant uptake in TLC treatments was reduced by up to 78% and differences between the two applied doses were small. Correspondingly, significant adverse effects were observed for L. variegatus whenever AC was present in the sediment. The lowest application dose of 0.1% AC in the MIX system reduced L. variegatus growth, and 1.0% AC led to a net loss of organism biomass. All TLC treatments let to a loss of biomass in the test organism. Furthermore, mortality was observed with 1.2 kg AC/m2doses of pure AC for the TLC treatment. The addition of clay (Kaolinite) to the TLC treatments prevented mortality, but did not decrease the loss in biomass. While TLC treatments pose a less laborious alternative for AC amendments in the field, the results of this study show that it has lower remediation potential and could be more harmful to the benthic fauna.
authors.affiliation: University of Eastern Finland, Department of Environmental and Biological Sciences, P.O.Box 111, FI-80101 Joensuu, Finland. Electronic address: sebastian.abel@uef.fi.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Abel
authors.affiliation: University of Eastern Finland, Department of Environmental and Biological Sciences, P.O.Box 111, FI-80101 Joensuu, Finland.
authors.forename: Inna
authors.initials: I
authors.lastname: Nybom
authors.affiliation: University of Eastern Finland, Department of Environmental and Biological Sciences, P.O.Box 111, FI-80101 Joensuu, Finland.
authors.forename: Kimmo
authors.initials: K
authors.lastname: Mäenpää
authors.affiliation: Norwegian Geotechnical Institute (NGI), P.O.Box 3930 Ullevaal, NO-0806 Oslo, Norway.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Hale
authors.affiliation: Norwegian Geotechnical Institute (NGI), P.O.Box 3930 Ullevaal, NO-0806 Oslo, Norway; Department of Environmental Sciences (IMV), Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432 Ås, Norway; Department of Environmental Sciences and Analytical Chemistry (ACES), Stockholm University, 10691 Sweden.
authors.forename: Gerard
authors.initials: G
authors.lastname: Cornelissen
authors.affiliation: University of Eastern Finland, Department of Environmental and Biological Sciences, P.O.Box 111, FI-80101 Joensuu, Finland.
authors.forename: Jarkko
authors.initials: J
authors.lastname: Akkanen
mesh_terms: D000818:Animals; D002606:Charcoal / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D009835:Oligochaeta / Q000187:drug effects
chemical_list: D002606:Charcoal
keywords: Activated carbon; Adverse effects; Bioaccumulation; PCB; Sediment remediation; Thin layer capping