Isolation and characterization of biochar-derived organic matter fractions and their phenanthrene sorption
Isolation and characterization of biochar-derived organic matter fractions and their phenanthrene sorption
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生物炭衍生有机物组分的分离和表征及其菲吸附
DOI：
10.1016/j.envpol.2018.02.015
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发表时间：
2018-05-01
影响因子：
8.9
通讯作者：
Wang, Xiangke
中科院分区：
文献类型：
--
作者：
Jin, Jie;Sun, Ke;Wang, Xiangke
生物炭衍生有机物组分（BDOMs）的化学组成和污染物吸附对于理解生物炭的长期环境意义至关重要。研究了从植物秸秆和动物粪便生物炭中分离的类胡敏酸（HAL）组分及其提取后的残渣（RES）对菲（PHE）的吸附作用。HAL级分包含原始生物炭的约50%的有机碳（OC）。XPS和C-13 NMR结果表明，生物炭衍生的HAL组分主要由羧基取代的芳香簇组成。BDOMs的CO2累积比表面积明显低于相应生物炭。新鲜生物炭对菲的吸附非线性明显强于BDOM组分，表明BOOM组分的化学性质更为均一。与原始生物炭相比，BDOM通常表现出相当或更高的PHE的OC归一化分布系数（K-oc）。由于空间位阻效应，新鲜生物炭的PHE logK（oc）值与生物炭体积呈负相关。与此相反，在这项研究中观察到的BDOMs的吸附系数（Kd）和吸附体积之间的正相关关系，这表明孔隙填充可以主导苯丙氨酸的吸附BDOMs。HAL组分的PHE logK（oc）值与芳香碳含量之间的正相关性表明，HAL组分对PHE的吸附受芳香结构域的调节。这项研究的结果提高了我们对生物炭应用后性质演变及其潜在环境影响的认识。(C)2018爱思唯尔有限公司版权所有。
Chemical composition and pollutant sorption of biochar-derived organic matter fractions (BDOMs) are critical for understanding the long-term environmental significance of biochar. Phenanthrene (PHE) sorption by the humic acid-like (HAL) fractions isolated from plant straw- (PLABs) and animal manure-based (ANIBs) biochars, and the residue materials (RES) after HAL extraction was investigated. The HAL fraction comprised approximately 50% of organic carbon (OC) of the original biochars. Results of XPS and C-13 NMR demonstrated that the biochar-derived HAL fractions mainly consisted of aromatic clusters substituted by carboxylic groups. The CO2 cumulative surface area of BDOMs excluding PLAB-derived RES fractions was obviously lower than that of corresponding biochars. The sorption nonlinearity of PHE by the fresh biochars was significantly stronger than that of the BDOM fractions, implying that the BOOM fractions were more chemically homogeneous. The BDOMs generally exhibited comparable or higher OC-normalized distribution coefficients (K-oc) of PHE than the original biochars. The PHE logK(oc) values of the fresh biochars correlated negatively with the micropore volumes due to steric hindrance effect. In contrast, a positive relationship between the sorption coefficients (K-d) of BDOMs and the micropore volumes was observed in this study, suggesting that pore filling could dominate PHE sorption by the BDOMs. The positive correlation between the PHE logK(oc) values of the HAL fractions and the aromatic C contents indicates that PHE sorption by the HAL fractions was regulated by aromatic domains. The findings of this study improve our knowledge of the evolution of biochar properties after application and its potential environmental impacts. (C) 2018 Elsevier Ltd. All rights reserved.