Molecular markers of benzene polycarboxylic acids in describing biochar physiochemical properties and sorption characteristics
Molecular markers of benzene polycarboxylic acids in describing biochar physiochemical properties and sorption characteristics
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描述生物炭理化性质和吸附特性的苯多羧酸分子标记
DOI：
10.1016/j.envpol.2018.02.071
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发表时间：
2018-06-01
影响因子：
8.9
通讯作者：
Pan, Bo
中科院分区：
文献类型：
--
作者：
Chang, Zhaofeng;Tian, Luping;Pan, Bo
生物炭在土壤中的功能是基于吸附特性等性质的，这些特性预计会在生物炭的整个生命周期中发生变化。由于生物炭颗粒不容易从土壤颗粒中分离出来，这种变化很少被研究。生物炭相关分子标记物，如苯多羧酸(BPCA)，是研究复杂环境基质中生物炭性质的很有前途的工具。本研究以玉米秸秆和松木木屑为原料，在200-500℃的温度下制备生物炭，并用NaClO模拟其老化过程。通过元素分析、BET表面表征和BPCA分子标记分析对生物炭的性质进行了表征。化学氧化降低了生物炭的比表面积，但增加了氧含量。氧化减少了生物炭的量，质量损失在10-55%之间。BPCA也有类似的质量损失，并且与热解温度和凝聚结构的程度(较高的芳香度)呈负相关。用BPCA含量之和定量计算生物炭含量，换算因子(生物炭含量与BPCA含量之比)在3.3~5.5之间，与B5CA含量呈负相关。选择双酚A(BPA)、磺胺甲恶唑(SMX)和菲(Phe)三种模型污染物，研究了氧化前后生物炭的吸附特性。化学氧化一般会增加SMX的吸附，但降低Phe的吸附。基于Freundlich方程模型的非线性因子n与所有三种化学物质的b6ca呈负相关。BPCA分子标记，特别是B5ca和B6ca，与生物炭氧化前后的性质相关，因此是描述环境中生物炭特征的一种潜在有用的技术。(C)2018爱思唯尔有限公司。保留所有权利。
Biochar function in soil is based on properties such as sorption characteristics, and these are expected to change throughout the life cycle of the biochar. Because biochar particles cannot easily be separated from soil particles, this change is seldom investigated. Biochar-related molecular markers, such as benzene polycarboxylic acids (BPCAs) are promising tools for studying the properties of biochars in complex environmental matrices. In this study, biochars were derived from corn straw and pine wood sawdust at 200-500 degrees C, and their aging was simulated with NaClO. Biochar properties were characterized by elemental analysis, BET surface characterization and BPCA molecular marker analysis. Chemical oxidation decreased the surface area (SA) but increased the O content of biochars. The oxidation decreased the amount of biochars, with a mass loss in the range of 10-55%. A similar mass loss was also observed for BPCAs and was negatively related to both the pyrolysis temperature and the extent of the condensed structure (higher aromaticity). The biochar amounts were calculated quantitatively using the sum of BPCA contents, with a conversion factor (the ratio of biochar amount to BPCA content) in the range of 3.3-5.5, and were negatively related to the B5CA content. Three model pollutants, namely, bisphenol A (BPA), sulfamethoxazole (SMX), and phenanthrene (PHE), were chosen to study the sorption characteristics of biochar before and after oxidation. Chemical oxidation generally increased SMX sorption but decreased PHE sorption. The nonlinear factor n, based on Freundlich equation modeling, was negatively related to B6CA for all three chemicals. The BPCA molecular markers, especially B5CA and B6CA, were correlated to the biochar properties before and after oxidation and are thus a potentially useful technique for describing the characteristics of biochar in the environment. (C) 2018 Elsevier Ltd. All rights reserved.