State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China.
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
Chemosphere. 2021 Aug;276:130139. doi: 10.1016/j.chemosphere.2021.130139. Epub 2021 Mar 2.
A kind of biosurfactant rhamnolipid modified zero-valent iron nanoparticles have been synthesized and applied to evaluate the immobilization efficiency of Ni (Ⅱ) contaminated soil at three concentration levels (200Ni, 600Ni and 1800Ni). The results of SEM and XRD were clearly indicative of the well-attached phenomenon of rhamnolipid on the nZVI, featuring better stability and dispersity, and FTIR analysis proposed the interactions between rhamnolipid and nZVI through monodentate chelating between carboxylate groups and nZVI or hydrogen bonding with Fe-O groups on the surface. Sequential extraction procedures (SEP) analysis illustrated that the majority of labile fractions had been transformed into less accessible fractions (Fe-Mn oxide-bound fractions and residual fractions) after 28 days of incubation. And for low-concentrations polluted soil, soil self-remediation played a dominant role, while RL@nZVI exhibited a more significant stabilizing effect for medium and high-concentrations pollution. Furthermore, XPS and XRD analyses of Ni-adsorbed RL@nZVI identified the formation of NiO, Ni(OH) and revealed the possible interaction mechanisms including reduction, adsorption and precipitation/co-precipitation. These results confirmed that RL@nZVI presented a promising prospect for the immobilization of Ni polluted soil.
已合成了一种生物表面活性剂鼠李糖脂修饰的零价铁纳米颗粒，并将其应用于评估三种浓度水平（200Ni、600Ni 和 1800Ni）下 Ni（Ⅱ）污染土壤的固定效率。SEM 和 XRD 的结果清楚地表明了鼠李糖脂在 nZVI 上的良好附着现象，具有更好的稳定性和分散性，FTIR 分析提出了鼠李糖脂和 nZVI 之间通过羧酸盐基团与 nZVI 的单齿螯合或与表面的 Fe-O 基团的氢键相互作用。顺序提取程序（SEP）分析表明，在 28 天的孵育后，大部分不稳定分数已转化为更难接近的分数（Fe-Mn 氧化物结合分数和残留分数）。对于低浓度污染土壤，土壤自修复起主导作用，而 RL@nZVI 对中高浓度污染表现出更显著的稳定作用。此外，Ni 吸附的 RL@nZVI 的 XPS 和 XRD 分析确定了 NiO、Ni(OH)的形成，并揭示了可能的相互作用机制，包括还原、吸附和沉淀/共沉淀。这些结果证实 RL@nZVI 为固定 Ni 污染土壤提供了有前景的前景。
