生物炭对PFOS在湖泊沉积物中迁移及生物有效性影响的构效特征和机制研究

The lakes are important water sources and fishing base. Thus, it is vital and significant to the safety of the lake water and aquatic ecosystem health carrying out the study on the fate of organic compounds in water and sediment. Biochar is a key factor to impact the transportation and transformation of organic pollutants in sediment for its strong sorption af?nity for organic contaminants. However, for the heterogeneity of biochar and the different natures of organic pollutants, the effects and mechanism of biochar on the transportation and availability of organic pollutants in lake sediments still need to explore in further. PFOS is a new persistent organic pollutant and has dual characteristics both hydrophobic and hydrophilic, and was concerned in the world due to the potential bioaccumulation and the possible negative impact on the total environment. Biochar, an important organic component in lake sediments or soil, has been the concerned hot spots of environmental chemists. In this study, the effect of biochar derived from different biomass and produced process on the mechanism of PFOS transportation and bioavailability in sediment will be researched. Firstly, biochar will be produced from the different biomass and generating process. Then, some sequencing batch experiments including adsorption and desorption will be implemented between PFOS and biochar, PFOS and sediment contained a certain percentage of biochar respectively. At last, organism enrichment experiment to PFOS in water-sediment system contained biochar will be carried out. At the whole test process, the characteristics of biochar and sediment before and after the adsorption and desorption will be determined with with scanning electron microscopy, infrared spectroscopy, X-ray diffraction and NMR structural characterization methods. According to above mentioned study, the relationship between biochar structural composition and performance of PFOS adsorption and desorption will be in-depth understood; the mechanism of the effect of biochar on sediment adsorbing and desorbing PFOS will be better clarified; and the inherent influenced roles of biochar on bioavailability of PFOS will be clear shown. The study is expected to increase the depth of understanding of PFOS fate at the water-sediment interface, and provides an important theoretical basis and technical support for PFOS pollutants control and risk prediction in water environment.

湖泊是重要的水源地和渔业基地，开展湖泊水/沉积物中有机物归趋行为的研究对保障湖泊水体安全和水生态健康具有重要的理论价值和现实意义。生物炭是影响沉积物中有机物迁移转化的关键因子，然而由于生物炭的异质性和有机物特性的差异，生物炭对沉积物中有机物迁移和有效性影响的效果和机理上有所不同，还有深入研究的潜力。本研究以具有疏水和亲水双重特性的有机物PFOS为目标物，以不同来源和产生过程的生物炭为切入点，通过室内模拟的吸附解吸和生物体富集实验，借助扫描电镜、红外光谱、X射线衍射及核磁共振等结构特性表征手段，深入认识生物炭的结构特性对PFOS吸附解吸行为作用影响的机制；阐明生物炭对沉积物中PFOS吸附性能和解吸迟滞效应影响的机理；揭示生物炭对沉积物PFOS生物有效性影响的内在规律。本研究有望提高水-沉积物界面PFOS迁移转化的机制认识的深度，为水环境中PFOS污染物的控制和治理提供重要的理论依据和技术支撑

湖泊是重要的水源地和渔业基地，开展湖泊水-沉积物界面有机污染物归趋的研究对湖泊的保护至关重要。本研究以我国生产使用量较大、毒性危害较强、在湖泊水环境赋存较多的全氟化合物PFOS为目标有机污染物，以影响水沉积物界面有机物迁移转化的关键因素生物炭为切入点，探讨不同热解温度下的生物炭对水-沉积物界离子型化合物PFOS迁移转化和生物有效性特征的影响。研究表明，高温显著改善了生物炭的芳香结构、孔隙和表面积，吸附量随着温度的升高而增加，PFOS符合伪二动力学和Freundlich等温模型 (R2> 0.93)，PFOS的吸附作用机制为疏水和静电作用，生物炭的添加有助于沉积物中PFOS稳定并降低PFOS的生物富集作用，生物炭可以很好应用在湖泊沉积物有机污染的修复。