title: Bioavailability assessment of hexachlorobenzene in soil as affected by wheat straw biochar.
abstract: Biochar incorporation with soil could increase sorption of organic contaminants, thereby reducing their bioavailability. In this study, the effects of wheat straw biochar on the sorption, dissipation and bioavailability of hexachlorobenzene (HCB), a typical persistent organic pollutant (POP), were investigated in laboratory experiments. We observed that HCB sorption by biochar was 42 times higher than that by soil and the sorption isotherm was linear for the concentration range studied. Biochar amendments reduced HCB dissipation, volatilization and earthworm (Eisenia foetida) uptake of HCB from soil. Hydroxypropyl-β-cyclodextrin extraction correlated better with the earthworm bioassay than butanol extraction of HCB in biochar-amended soil. The results of both chemical extraction and earthworm bioassay indicate that biochar amendment of soil resulted in a rapid reduction in the bioavailability of HCB, even for the 0.1% biochar application rate. This suggested that wheat straw biochar could potentially be used in immobilizing POPs in contaminated sites.
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Song
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Yongrong
authors.initials: Y
authors.lastname: Bian
authors.forename: Fredrick Orori
authors.initials: FO
authors.lastname: Kengara
authors.forename: Mingyun
authors.initials: M
authors.lastname: Jia
authors.forename: Zubin
authors.initials: Z
authors.lastname: Xie
authors.forename: Xin
authors.initials: X
authors.lastname: Jiang
mesh_terms: D000818:Animals; D001682:Biological Availability; D002849:Chromatography, Gas; D006581:Hexachlorobenzene / Q000493:pharmacokinetics*; D009835:Oligochaeta / Q000378:metabolism; D011786:Quality Control; D012989:Soil Pollutants / Q000493:pharmacokinetics*; D017550:Spectroscopy, Fourier Transform Infrared; D014908:Triticum / Q000378:metabolism*
chemical_list: D012989:Soil Pollutants; D006581:Hexachlorobenzene