title: A critical evaluation of magnetic activated carbon's potential for the remediation of sediment impacted by polycyclic aromatic hydrocarbons.
abstract: Addition of activated carbon (AC) or biochar (BC) to sediment to reduce the chemical and biological availability of organic contaminants is a promising in-situ remediation technology. But concerns about leaving the adsorbed pollutants in place motivate research into sorbent recovery methods. This study explores the use of magnetic sorbents. A coal-based magnetic activated carbon (MAC) was identified as the strongest of four AC and BC derived magnetic sorbents for polycyclic aromatic hydrocarbons (PAHs) remediation. An 8.1% MAC amendment (w/w, equal to 5% AC content) was found to be as effective as 5% (w/w) pristine AC in reducing aqueous PAHs within three months by 98%. MAC recovery from sediment after three months was 77%, and incomplete MAC recovery had both, positive and negative effects. A slight rebound of aqueous PAH concentrations was observed following the MAC recovery, but aqueous PAH concentrations then dropped again after six months, likely due to the presence of the 23% unrecovered MAC. On the other hand, the 77% recovery of the 8.1% MAC dose was insufficient to reduce ecotoxic effects of fine grained AC or MAC amendment on the egestion rate, growth and reproduction of the AC sensitive species Lumbriculus variegatus.
authors.affiliation: School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, England, United Kingdom; Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Hebei Key Laboratory of Groundwater Remediation, Shijiazhuang 050061, China.
authors.forename: Zhantao
authors.initials: Z
authors.lastname: Han
authors.affiliation: School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, England, United Kingdom.
authors.forename: Badruddeen
authors.initials: B
authors.lastname: Sani
authors.affiliation: Department of Biology, University of Eastern Finland (UEF), P.O. Box 111, FI-80101 Joensuu, Finland.
authors.forename: Jarkko
authors.initials: J
authors.lastname: Akkanen
authors.affiliation: Department of Biology, University of Eastern Finland (UEF), P.O. Box 111, FI-80101 Joensuu, Finland.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Abel
authors.affiliation: Department of Biology, University of Eastern Finland (UEF), P.O. Box 111, FI-80101 Joensuu, Finland.
authors.forename: Inna
authors.initials: I
authors.lastname: Nybom
authors.affiliation: Department of Chemistry, University of Patras, 26500 Patras, Greece.
authors.forename: Hrissi K
authors.initials: HK
authors.lastname: Karapanagioti
authors.affiliation: School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, England, United Kingdom. Electronic address: david.werner@ncl.ac.uk.
authors.forename: David
authors.initials: D
authors.lastname: Werner
mesh_terms: D000818:Animals; D002244:Carbon / Q000737:chemistry*; D002606:Charcoal / Q000737:chemistry; D003031:Coal; D004463:Ecology; D052918:Environmental Restoration and Remediation / Q000379:methods*; D019015:Geologic Sediments; D007700:Kinetics; D008280:Magnetics; D008855:Microscopy, Electron, Scanning; D009835:Oligochaeta / Q000187:drug effects; D010316:Particle Size; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D015203:Reproducibility of Results; D014867:Water / Q000737:chemistry; D014873:Water Pollutants / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000379:methods*
chemical_list: D003031:Coal; D011084:Polycyclic Aromatic Hydrocarbons; D014873:Water Pollutants; D014874:Water Pollutants, Chemical; C540010:biochar; D014867:Water; D002606:Charcoal; D002244:Carbon
keywords: Ecotoxicity; Magnetic activated carbon; PAHs; Sediment remediation