title: Effects of biochar on the transformation and earthworm bioaccumulation of organic pollutants in soil.
abstract: Little is known about the effects of biochar on the fate and behavior of micropollutants in soil, especially in the presence of soil macrofauna. Using a 14C-tracer, we studied the fate of 2,4-dichlorophenol and phenanthrene, after 30 days in soil in the presence of a biochar (0-5%, dry weight) produced from China fir at 400 °C and/or the earthworm Metaphire guillelmi. Application of the biochar significantly reduced the degradation and mineralization of both pollutants and strongly increased the accumulation of their metabolites in soil. The earthworm had no significant effects on the degradation of parent molecules of the pollutants but it significantly reduced the mineralization of the pollutants independent of the presence of the biochar. Although at an application rate of <1% the biochar strongly sorbed both pollutants, it did not significantly decrease the bioaccumulation of free dichlorophenol and phenanthrene and their metabolites by the earthworm. Our results demonstrate the complex effects of biochar on the fate, transformation, and earthworm bioaccumulation of organic pollutants in soil. They show that biochar application may not be an appropriate strategy for treating soil contaminated with hydrophobic organic pollutants and underline the importance of soil-feeding earthworms in risk assessments of biochar effects on soil remediation.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Xianlin Avenue 163, 210023 Nanjing, China.
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Xianlin Avenue 163, 210023 Nanjing, China.
authors.forename: Wenqiang
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Fujian Provincial Academy of Environmental Science, No.10, Huan Bei San Cun, Fuzhou 350013, China.
authors.forename: Bingqi
authors.initials: B
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Xianlin Avenue 163, 210023 Nanjing, China.
authors.forename: Lianhong
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Xianlin Avenue 163, 210023 Nanjing, China.
authors.forename: Yini
authors.initials: Y
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Xianlin Avenue 163, 210023 Nanjing, China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Guo
authors.affiliation: Institute of Terrestrial Ecosystems, ETH Zürich, Universitätstrasse 16, CH-8092 Zürich, Switzerland.
authors.forename: Rainer
authors.initials: R
authors.lastname: Schulin
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Xianlin Avenue 163, 210023 Nanjing, China; Institute for Marine Sciences & Institute for Climate and Global Change Research, Nanjing University, 22 Hankou Road, 210093 Nanjing, China. Electronic address: ji@nju.edu.cn.
authors.forename: Rong
authors.initials: R
authors.lastname: Ji
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Xianlin Avenue 163, 210023 Nanjing, China; Institute of Terrestrial Ecosystems, ETH Zürich, Universitätstrasse 16, CH-8092 Zürich, Switzerland. Electronic address: michael.evangelou@env.ethz.ch.
authors.forename: Michael W H
authors.initials: MW
authors.lastname: Evangelou
mesh_terms: D000818:Animals; D002606:Charcoal / Q000378:metabolism*; D002733:Chlorophenols / Q000378:metabolism*; D009835:Oligochaeta / Q000378:metabolism*; D010616:Phenanthrenes / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D002733:Chlorophenols; D010616:Phenanthrenes; D012989:Soil Pollutants; C540010:biochar; D002606:Charcoal; C031181:phenanthrene; C004762:2,4-dichlorophenol
keywords: Bioaccumulation; Bound residues; Chlorophenol; Mineralization; Phenanthrene