Guo Bingxin, Wei Yuexing, Liu Xiaona, Qian Tianwei, Guo Junmei, Yang Junxing, Chen Tongbin
College of Environment and Ecology, Taiyuan University of Technology, Shanxi Key Laboratory of Earth Surface Processes and Resource Ecological Security in Fenhe River Basin, Shanxi Engineering Research Center of Low Carbon Remediation for Water and Soil Pollution in Yellow River Basin, Jinzhong 030600, China.
College of Civil Engineering, Taiyuan University of Technology, Jinzhong, Shanxi 030600, China.
J Hazard Mater. 2025 Mar 15;486:137040. doi: 10.1016/j.jhazmat.2024.137040. Epub 2025 Jan 2.
The application of biodegradable chelating agents in phytoremediation is a promising approach. This study aimed to investigate the effects and roles of underlying mechanisms of water-soluble carboxymethyl chitosan (WSCC) and rhamnolipids (RLs) on the remediation of Cd-contaminated soil by Hylotelephium spectabile. WSCC and RLs mediated the growth of H. spectabile by increasing chlorophyll content and the activity of antioxidant enzymes as well as promoted the conversion of water-extractable Cd to HAc-extractable Cd in leaves. WSCC and RLs promoted the secretion of malic acid, acetic acid, and succinic acid by the roots; decreased soil pH; increased the number of functional groups, such as hydroxyl, amino, and carboxyl groups, in the soil; and changed the diversity and structure of bacterial communities in the soil, thereby improving the bioavailability of Cd in the soil and creating a good ecological environment of the rhizosphere. The combined application of WSCC and RLs had a better auxiliary effect than single application of either, especially under CR2 treatment (1.5 g·kg WSCC + 0.2 g·kg RLs), where the accumulation of Cd in plants significantly increased by 159.86 % compared with the control. These findings indicated that WSCC and RLs enhanced the remediation efficiency of H. spectabile by regulating both plant growth and the ecological environment of the rhizosphere.
可生物降解螯合剂在植物修复中的应用是一种很有前景的方法。本研究旨在探讨水溶性羧甲基壳聚糖（WSCC）和鼠李糖脂（RLs）对八宝景天修复镉污染土壤的潜在机制的影响及作用。WSCC和RLs通过增加叶绿素含量和抗氧化酶活性来介导八宝景天的生长，并促进叶片中可水溶态镉向可醋酸提取态镉的转化。WSCC和RLs促进根系分泌苹果酸、乙酸和琥珀酸；降低土壤pH值；增加土壤中羟基、氨基和羧基等官能团的数量；改变土壤细菌群落的多样性和结构，从而提高土壤中镉的生物有效性，营造良好的根际生态环境。WSCC和RLs联合施用的辅助效果优于单独施用，尤其是在CR2处理（1.5 g·kg WSCC + 0.2 g·kg RLs）下，与对照相比，植物中镉的积累量显著增加了159.86%。这些结果表明，WSCC和RLs通过调节植物生长和根际生态环境提高了八宝景天的修复效率。
