|Title||The effects of chemical, biological and physical aging as well as soil addition on the sorption of pyrene to activated carbon and biochar|
|Publication Type||Journal Article|
|Year of Publication||2011|
|Authors||Hale, Sarah E., Hanley Kelly, Lehmann Johannes, Zimmerman Andrew, and Cornelissen Gerard|
|Journal||Environ. Sci. Technol|
This study investigates the suitability of biochar and activated carbon (AC) for contaminated soil remediation by determining the sorption of pyrene to both materials in the presence and absence of soil and before as well as after aging. Biochar and AC were aged either alone or mixed with soil via exposure to a) nutrients and microorganisms (biological), b) 60 and 110 °C (chemical) and c) freeze-thaw cycles (physical). Before and after aging, the pH, elemental composition, cation exchange capacity (CEC), microporous SA and sorption isotherms of pyrene were quantified. Aging at 110 °C altered the physicochemical properties of all materials to the greatest extent (for example, pH increased by up to three units and CEC by up to 50 % for biochar). Logarithmic KFr values ranged from 7.80 to 8.21 (ng kg-1)(ng L-1)-n for AC and 5.22 to 6.21 (ng kg-1)(ng L-1)-n for biochar after the various aging regimes. Grinding biochar to a smaller particle size did not significantly affect the sorption of d10 pyrene, implying that sorption processes operate on the sub-particle scale. Chemical aging decreased the sorption of pyrene to the greatest extent (up to 1.8 log unit for the biochar+soil). The sorption to AC was affected more by the presence of soil than the sorption to biochar. Our results suggest that AC and biochar have a high sorption capacity for pyrene that is maintained both in the presence of soil and during harsh aging. Both materials could therefore be considered in contaminated land remediation.