麦秆还田可释放生物源甲苯
Wheat straw return can lead to biogenic toluene emissions
Ting Wu, Xiaoyu Zhao, Mengdi Liu, Juan Zhao, Xinming Wang
https://doi.org/10.1016/j.jes.2021.08.050
摘要
秸秆还田作为农业生态系统一项常用的措施，可释放大量痕量气体，引起了学者们广泛关注。但是，有关秸秆还田甲苯排放研究仍然缺乏。本论文分别测定了淹水和非淹水两种条件下麦秆还田释放出来的甲苯和50种其它挥发性有机物(VOCs)。结果表明，麦秆还田特别是在淹水条件下可释放大量甲苯，主要来自秸秆分解的二次生成产物。淹水和非淹水条件下麦秆还田甲苯排放量分别为36.8和8.45 mg C/kg，分别占总VOCs排放量的28.0%和8.6%，并且90%以上的甲苯排放量分别出现在24-56天和0-17天。两种水分条件下甲苯排放速率在麦秆还田初始都相对较高，在前2天都随时间迅速降低并且趋于稳定直到第24天；然后淹水条件下甲苯排放速率随时间重新升高在24-56天形成一个排放高峰，但是非淹水条件下甲苯排放速率仍然很低并且继续保持平稳直到实验结束。此外，淹水条件下甲苯排放速率与微生物C量显著正相关，但在非淹水条件下甲苯排放速率与细菌和真菌数量、微生物C量以及CO2排放速率显著负相关，表明微生物在麦秆还田甲苯排放过程中起着重要作用。据初步估算，秸秆还田可能对生物源甲苯具有重要贡献。
亮点
秸秆还田分解特别是在淹水条件下分解可释放大量甲苯，主要来自秸秆分解的二次生成产物，与微生物活动密切相关。
Abstract
As a common practice in agricultural system, straw return has been reported to release a large number of trace gases and attracted much attention. However, the role of straw return in toluene emission remains poorly understood. In this study we measured the emissions of toluene as well as other 50 volatile organic compounds (VOCs) from wheat straw return for 66 days under flooded and non-flooded conditions, respectively. The results showed that substantial toluene was released from the returned wheat straw particularly under flooded condition, and primarily derived from the secondary product. Toluene emissions from the returned wheat straw were 36.8 and 8.45 mg C/kg, sharing 28.0% and 8.6% of total VOCs released, and over 90% of toluene emissions occurred between days 24-56 and 0-17 under flooded and non-flooded conditions, respectively. The emission rates of toluene were relatively high but decreased sharply at the beginning 2 days, and then was steady until 24 days under the two moisture conditions. After the initial decrease these rose again to form one “peak emission window” between days 24-56 under flooded condition, while these were still very low and steady until the end under nonflooded condition. The toluene emission rates significantly positively correlated with microbial biomass C under flooded condition, but negatively associated with bacteria and fungus number, microbial biomass C, and CO2 flux under non-flooded condition, suggesting that microorganism might play an important role in toluene emissions from wheat straw return. A rough estimate indicated that straw return might be important for biogenic toluene.
作者简介
吴婷教授 于2008年在中国科学院广州地球化学研究所获得博士学位，现任安徽师范大学生态与环境学院教授，博士生导师。主要从事大气有机污染物（重点关注VOCs和GHGs）的大气化学过程、生物地球化学循环及其生态环境健康影响研究。在Environ. Sci. & Technol.、Atmos. Environ.、Chemosphere等国内外学术刊物上发表研究论文30余篇，申请和授权发明专利3项。
原文链接
https://www.sciencedirect.com/science/article/pii/S1001074221003557?via%3Dihub
引用格式
Ting Wu, Xiaoyu Zhao, Mengdi Liu, Juan Zhao, Xinming Wang, 2023. Wheat straw return can lead to biogenic toluene emissions. J. Environ. Sci. 124, 281-290.
