Removal of trichloroethylene by biochar supported nanoscale zero-valent iron in aqueous solution
Removal of trichloroethylene by biochar supported nanoscale zero-valent iron in aqueous solution
复制标题
生物炭负载纳米零价铁去除水溶液中的三氯乙烯
DOI：
10.1016/j.seppur.2017.07.033
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发表时间：
2017-11-29
影响因子：
8.6
通讯作者：
Zeng, Guangming
中科院分区：
文献类型：
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作者：
Dong, Haoran;Zhang, Cong;Zeng, Guangming
纳米零价铁（NZVI）被广泛应用于三氯乙烯（TCE）的降解，但存在易团聚、吸附容量低等缺点。为了克服NZVI的缺点，利用生物炭的高稳定性和吸附能力，采用生物炭改性NZVI颗粒（NZVI/BC）去除和降解三氯乙烯。研究了BC热解温度、NZVI/BC质量比和溶液pH对TCE去除和降解效果的影响。不同热解温度的炭在比表面积、芳香度和非芳香性组分上存在差异，从而决定了炭对三氯乙烯的吸附能力。与纯NZVI相比，不同质量比的NZVI/BC对三氯乙烯的去除率可提高到99%，这是由于BC对三氯乙烯的吸附量较大。此外，不同NZVI/BC质量比下，最终产物（乙烷、乙烯和乙炔）的产率不同。总的来说，所有反应的主要产物都是乙烯，乙炔和乙烷的产率相对较低。溶液pH值对TCE的总去除率影响不大，但对最终产物的产率有显着影响。结果表明，溶液pH值对NZVI/BC吸附TCE没有影响，但影响NZVI/BC对TCE的降解速率。(C)2017爱思唯尔B. V.保留所有权利。
Nanoscale zero-valent iron (NZVI) has been widely used for the degradation of trichloroethylene (TCE) in contaminated water, however, it is suffering from being easy to aggregate and having low adsorption capacity for TCE. In order to overcome the shortcomings of NZVI, modified NZVI particles with biochar (NZVI/BC) were applied in this study for removal and degradation of TCE, given the high stability and adsorption capacity of BC. The effects of pyrolysis temperature of BC, mass ratio of NZVI/BC and solution pH on the removal and degradation efficiency of TCE were studied. The different pyrolysis temperatures of BC resulted in the differences on the surface areas, aromaticity and noncarbonized fractions, which determined the sorption capacity of TCE. Compared with pure NZVI, the NZVI/BC at different mass ratios could increase the removal efficiency of TCE to 99%, which was attributed to the higher adsorption capacity of BC for TCE. Besides, the yield of final products (ethane, ethylene and acetylene) differed at different mass ratios of NZVI/BC. Generally, the main product was ethylene in all reactions and the yield of acetylene and ethane were relatively low. Solution pH had little effect on the total removal of TCE but significantly influenced the yield of final products. The yield of ethylene decreased with the increasing pH. The results indicate that solution pH could not affect the sorption of TCE but influenced the degradation rate of TCE by NZVI/BC. (C) 2017 Elsevier B.V. All rights reserved.