Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, PR China.
Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, PR China.
Chemosphere. 2021 Aug;277:130259. doi: 10.1016/j.chemosphere.2021.130259. Epub 2021 Mar 14.
In the present study, two magnetic multi-walled carbon nanotubes (MMWCNTs) with different ratios of Fe/Fe were prepared, and the effects of different fractions of dissolved humic acid (DHA) on the adsorption of phenanthrene by multi-walled carbon nanotubes (MWCNTs) and MMWCNTs from the aqueous solution were investigated. The adsorption kinetics of DHA and DHA were best fitted with pseudo-second order model. The adsorption of DHAs on MMWCNTs was weaker than that on MWCNTs, and DHA was easier to adsorb to MWCNTs and MMWCNTs than DHA. The phenanthrene adsorption capacities by 1:2:1MMWCNTs and 4:2:1MMWCNTs with higher polar groups and magnetic gradient were less than that of MWCNTs. The pH value had no obvious effect on the adsorption of phenanthrene to MWCNTs loaded with different iron. Additionally, the DHAs could form soluble complexes of DHAs-Fe (II) in solution to reduce the phenanthrene adsorption on MMWCNTs, DHA inhibit more obviously phenanthrene adsorbed onto MWCNTs and MMWCNTs than DHA. As for MMWCNTs, the main mechanisms of phenanthrene adsorbed onto it included new adsorption sites formed by π-π interaction and magnetic gradient. In this study, MMWCNTs after adsorbed DHAs had a weaker inhibitory effect on phenanthrene adsorption than MWCNTs, implying that when phenanthrene is adsorbed by DHAs-coated MMWCNTs, the bioavailability and mobility of phenanthrene will be reduced, and it is easy to be removed by the magnet for further processing.
在本研究中，制备了两种具有不同 Fe/Fe 比例的磁性多壁碳纳米管（MMWCNTs），并研究了不同比例的溶解腐殖酸（DHA）对多壁碳纳米管（MWCNTs）和 MMWCNTs 从水溶液中吸附菲的影响。DHA 和 DHA 的吸附动力学均最好用拟二级模型拟合。DHA 在 MMWCNTs 上的吸附比在 MWCNTs 上弱，且 DHA 比 DHA 更容易吸附到 MWCNTs 和 MMWCNTs 上。具有更高极性基团和磁梯度的 1:2:1MMWCNTs 和 4:2:1MMWCNTs 对菲的吸附容量小于 MWCNTs。pH 值对负载不同铁的 MWCNTs 吸附菲没有明显影响。此外，DHA 可以在溶液中形成 DHA-Fe（II）可溶性配合物，从而降低 MMWCNTs 对菲的吸附，DHA 比 DHA 更明显地抑制菲吸附到 MWCNTs 和 MMWCNTs 上。对于 MMWCNTs，菲吸附到其上的主要机制包括由 π-π 相互作用和磁梯度形成的新吸附位点。在本研究中，吸附 DHA 后的 MMWCNTs 对菲吸附的抑制作用比 MWCNTs 弱，这表明当 DHA 包覆的 MMWCNTs 吸附菲时，菲的生物有效性和迁移性会降低，并且很容易被磁铁去除进行进一步处理。
