Impact of Deashing Treatment on Biochar Structural Properties and Potential Sorption Mechanisms of Phenanthrene

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• 作者：Ke Sun ; Mingjie Kang ; Zheyun Zhang ; Jie Jin ; Ziying Wang ; Zezhen Pan ; Dongyu Xu ; Fengchang Wu ; Baoshan Xing
• 刊名：Environmental Science & Technology
• 出版年：2013
• 出版时间：October 15, 2013
• 年：2013
• 卷：47
• 期：20
• 页码：11473-11481
• 全文大小：414K
• 年卷期：v.47,no.20(October 15, 2013)
• ISSN：1520-5851

文摘

Knowledge of the mineral effects of biochars on their sorption of hydrophobic organic contaminants (HOCs) is limited. Sorption of phenanthrene (PHE) by plant-residue derived biochars (PLABs) and animal waste-derived biochars (ANIBs) obtained at two heating treatment temperatures (HTTs) (450 and 600 掳C) and their corresponding deashed biochars was investigated. The decreased surface polarity and increased bulk polarity of biochars after deashing treatment indicated that abundant minerals of biochars benefit external exposure of polar groups associated organic matter (OM). Organic carbon (OC)-normalized distribution coefficients (K_oc) of PHE by biochars generally increased after deashing, likely due to enhancement of favorable and hydrophobic sorption sites caused by mineral removal. Positive correlation between PHE log K_oc by PLABs and bulk polarity combined with negative correlation between PHE log K_oc values by ANIBs and surface polarity suggested PLABs and ANIBs have different sorption mechanisms, probably attributed to their large variation of ash content because minerals influenced OM spatial arrangement within biochars. Results of this work could help us better understand the impact of minerals, bulk/surface polarity, and sorption domain arrangement of biochars on their HOCs sorption and predict the fate of HOCs in soils after biochar application.