Magnetic ZrO2/PEI/Fe3O4 functionalized MWCNTs composite with enhanced phosphate removal performance and easy separability. (15th May 2022)

• Record Type: Journal Article
• Authors: Liu, Xiaohuan; Cheng, Wenwu; Yu, Yangmi; Jiang, Shengtao; Xu, Yuzhi; Zong, Enmin
• Is Part Of: Composites. Number 237(2022)
• Publication Date: 2022-05-15
• Subjects: Magnetic -- Multi-walled carbon nanotubes (MWCNTs) -- Zirconium oxide -- Phosphate removal -- Adsorption mechanism; Composite materials -- Periodicals; Materials science -- Periodicals; Composite materials; Periodicals; Electronic journals; 620.118
• DOI: 10.1016/j.compositesb.2022.109861
• Languages: English
• ISSNs: 1359-8368

Abstract

Abstract: A novel adsorbent of ZrO2 /PEI/Fe3 O4 functionalized MWCNTs composite (MWCNTs@Fe3 O4 @PEI-Zr) possessing a high affinity to phosphate and easily separated from aqueous solution was proposed in this work. The ZrO2 and PEI modified on the surface act as active sites for the removal of phosphate, while the Fe3 O4 allows for the easy separation by applying an external magnetic field. Compared to traditional separation like centrifugation, magnetic separation markedly reduces energy consumption and provides more possibilities for application. The composite exhibits a relatively high surface area of 162.9 m 2 g -1 with a larger number of mesopores. As-prepared MWCNTs@Fe3 O4 @PEI-Zr is found to have a relatively high phosphate adsorption capacity of 21.14 mg P g −1 and it can be recovered rapidly from water under an external magnetic field. Moreover, MWCNTs@Fe3 O4 @PEI-Zr exhibits an outstanding anti-interference capability in terms of the coexisting ion and ionic strength of solutions. Importantly, the dissolution of Zr and Fe are negligible (less than 0.015 mg L −1 ) over a wide pH range of 4.04–9.98, indicating that the MWCNTs@Fe3 O4 @PEI-Zr is a structurally stable hybrid composite particle with strong interaction. Furthermore, it shows a good reusability and 86.2% removal efficiency of phosphate remains after three consecutive cycles. Both the ligand exchange and the electrostatic attraction are mainly responsible for phosphate removal by MWCNTs@Fe3 O4 @PEI-Zr. This work demonstrated that the highly efficient, easy separable, high stability and reusability MWCNTs@Fe3 O4 @PEI-Zr composite has the potential for phosphate removal. Graphical abstract: Image 1 A novel magnetic adsorbent MWCNTs@Fe3 O4 @PEI-Zr composite with easy separability, high stability and good selectivity for the enhanced phosphate removal was successfully fabricated. Highlights: A novel magnetic composite MWCNTs@Fe3 O4 @PEI-Zr for phosphate removal was prepared. Magnetic composite has a high phosphate adsorption capacity of 21.14 mg P g −1 . Magnetic composite can be recovered rapidly from aqueous solution. Magnetic composite shows highly selective capacity and good reusability. A new mechanism for phosphate removal has been proposed by magnetic composite.