Yang Song Fang Wang Fredrick Orori Kengara Xinglun Yang Chenggang Gu and Xin Jiang. Immobilization of Chlorobenzenes in Soil Using Wheat Straw Biochar. J. Agric. Food Chem. 2013 DOI: 10.1021-jf400412p

Abstract

Biochar has shown great potential for immobilizing organic contaminants in soil. In this study pentachlorobenzene (PeCB) 1245-tetrachlorobenzene (1245-TeCB) and 124-trichlorobenzene (124-TCB) artificially-spiked soil was amended with wheat straw biochar at 0.1% 0.5% 1% and 2% application rates respectively. The sorption dissipation and bioavailability of chlorobenzenes (CBs) in soil were investigated. The sorption of PeCB by biochar was significantly higher than that of its sorption by both biochar-amended and unamended soil (p < 0.05). The dissipation and volatilization of CBs from biochar-amended soil significantly decreased relative to unamended soil (p < 0.05). Bioavailability of CBs expressed as butanol extraction efficiency and earthworm (Eisenia foetida) bioaccumulation factor significantly decreased with increasing aging time and biochar application rate. The effect of biochar content in soil on the bioavailability of CBs was more pronounced for 124-TCB relative to other CBs. This study suggested that wheat straw biochar even at low application rates could effectively immobilize the semi-volatile CBs in soil and thus reduce their volatilization and bioavailability.