Supported by the National Natural Science Foundation of China（No. 41771255）
【Objective】Root exudates are the main sources of dissolved organic matter, which can affect the stability and transport behaviors of colloids in porous media to some extent. With the wide application of biochar in soils, it is very important to understand the effects of root exudates on the stability and mobility of biochar colloids in the subsurface environment. 【Method】Galactose (Gal), lysine (Lys) and acetic acid (AcOH) are the typical components of root exudates. This study investigated the effects of Gal, Lys and AcOH on the stability and transport behaviors of wheat biochar (WB) and pine sawdust biochar (PB) colloids by aggregation and transport experiments. 【Result】The results showed that the concentration of root exudates had a certain influence on the ζ potential of biochar particles. At low Gal and Lys concentrations, their effects on the aggregation and transport of biochar colloids were small, thus, there were no significant effects on the environmental behavior of biochar colloids. In contrast, AcOH reduced the stability of biochar colloids in NaCl solution and inhibited the transport of biochar colloids in porous media. This may be related to the fact that the organic acid anions in acetic acid were easy to form hydrogen bonds with the oxygen-containing functional groups on the surface of biochar. Thus, the adsorption of AcOH by biochar was increased and the stability of biochar colloids was decreased. 【Conclusion】The concentration of root exudates such as Gal and Lys plays an important role in their ability to influence the aggregation and transport of biochar colloids. However, the adsorption of AcOH, even at low concentrations, significantly affects the aggregation and transport of biochar colloids.
潘岳,张雨,王洋,商建英.根系分泌物典型组分对生物炭胶体稳定性和迁移能力的影响[J].土壤学报,2023,60(3):824-834. DOI:10.11766/trxb202107110358 PAN Yue, ZHANG Yu, WANG Yang, SHANG Jianying. Effects of Typical Components of Root Exudates on the Stability and Transport of Biochar Colloids[J]. Acta Pedologica Sinica,2023,60(3):824-834.复制