Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education/Fujian Provincial Key Laboratory for Plant Eco-Physiology/School of Geographical Sciences, Fujian Normal University, Fuzhou, Fujian 350007, China.
Henan Joint International Research Laboratory of Environmental Pollution Control Materials, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, China.
Water Res. 2021 Sep 15;203:117515. doi: 10.1016/j.watres.2021.117515. Epub 2021 Aug 4.
Dissolved organic carbon derived from biomass-pyrogenic smoke (SDOC) can be transported and deposited with atmospheric aerosols, enter aqueous environments, and possibly alter aqueous chemistry and quality. However, the characteristics of SDOC in aqueous environments and their effects on the fate of hydrophobic organic pollutants are poorly understood. In this study, we found that the emitted SDOC is 7.2∼19.6 wt.% of biochar retained in situ after biomass pyrolysis, and the emitted SDOC is approximately 1-3 orders of magnitude greater than dissolved organic carbon (DOC) released from biochar in a short term, which indicates that SDOC is a more important source of DOC in aqueous environments relative to biochar-released DOC after a biomass burning/pyrolysis event. The characteristics of SDOC in aqueous environments are dominated by the <1000 Da fraction, which accounts for >96 wt.% of bulk SDOC. In comparison with DOC in biochar, natural water, and soil, the S value of SDOC (0.037-0.053) is significantly greater, further indicating that SDOC has a smaller molecular size. Moreover, fluorescence EEM suggests that a fluorescence component located at the Ex/Em of 205/310 nm and the combinational ranges of fluorescence index (1.28-2.28), humification index (0.07-0.80), and biological index (1.16-1.72) can be used to identify SDOC from DOC in other media. Solubilization experiments indicated that SDOC (20 mg/L) improved the solubility of hydrophobic pollutants (pyrene and triclocarban) by 2-6 folds in aqueous environments, which potentially enhances the mobility of pollutants and enlarges the potential risk region. This study indicates that SDOC may cause a severe harm to aqueous environments in addition to the atmosphere. The results have profound implications for comprehensive assessments of the environmental effects of SDOC while promoting its identification and elucidating its behavior in aqueous environments.
生物质热解衍生的生源-热成因有机碳(SDOC)可以与大气气溶胶一起传输和沉积,进入水相环境,并可能改变水相化学和水质。然而,人们对水相环境中 SDOC 的特性及其对疏水性有机污染物命运的影响知之甚少。在这项研究中,我们发现,生物质热解过程中,原位保留的生物炭中释放的 SDOC 占 7.2∼19.6wt.%,而在短期内,从生物炭中释放的 SDOC 比释放的溶解有机碳(DOC)大 1-3 个数量级,这表明在生物质燃烧/热解事件后,相对于生物炭释放的 DOC,SDOC 是水相环境中 DOC 的更重要来源。水相环境中 SDOC 的特征主要由<1000 Da 部分主导,占总 SDOC 的>96wt.%。与生物炭、天然水和土壤中的 DOC 相比,SDOC 的 S 值(0.037-0.053)显著更大,进一步表明 SDOC 的分子尺寸更小。此外,荧光 EEM 表明,一个荧光组分位于 205/310nm 的 Ex/Em 值,以及荧光指数(1.28-2.28)、腐殖化指数(0.07-0.80)和生物指数(1.16-1.72)的组合范围内的荧光组分可用于识别其他介质中的 SDOC 和 DOC。溶出实验表明,SDOC(20mg/L)在水相环境中使疏水性污染物(芘和三氯卡班)的溶解度提高了 2-6 倍,这可能会增强污染物的迁移能力,并扩大潜在的风险区域。本研究表明,SDOC 除了对大气造成严重危害外,还可能对水相环境造成严重危害。研究结果对全面评估 SDOC 的环境影响具有重要意义,同时也促进了对 SDOC 在水相环境中的识别和行为的研究。