Screening of optimum composition of superparamagnetic nanocomposite microparticles modified with various layered double hydroxides for phosphorus removal

• Published in: Journal of water process engineering Vol. 49; p. 103001
• Main Authors: Sürmeli, Mehmet, Yazıcı, Hüseyin, Kılıç, Mehmet, Karaboyacı, Mustafa
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2022
• Subjects: Dissolution; LDH; Magnetic NCMP; P removal; Stability; P removal; LDH; Stability; Magnetic NCMP; Dissolution
• ISSN: 2214-7144; 2214-7144
• DOI: 10.1016/j.jwpe.2022.103001

Superparamagnetic nanocomposite microparticles (NCMPs) modified with various layered double hydroxides (LDHs) (MgFe, MgAl and their Zr-doped equivalents) were investigated for phosphorus (P) removal. Screening of optimum composition was performed based on the P removal performance of NCMP@LDH particles as well as their magnetic separability in a flow-through column as a function of NCMP content (100–1000 mg) and stability as a function of LDH content (20–100%). The results showed that except for NCMP@MgFe-Zr, all the other particles exhibited a partial dissolution of LDH components at each of the examined LDH contents. However, NCMP@MgFe-Zr showed no dissolution up to a LDH content of 60% at all, whereas a partial dissolution occurred at a LDH content of 80 and 100%. Results of magnetic separability test revealed that the NCMP@MgFe-Zr composed of 500 mg magnetic particle (NCMP) and 60% LDH was separated from the solution with a separation efficiency of 96.9%, while lower NCMP contents resulted in lower separation efficiencies. P removal efficiency and specific removal capacity of the NCMP@MgFe-Zr with the optimized composition was found to be 18.5% and 53.1 mg/g, respectively. The crystal structure, chemical composition, surface morphology, crystallite size and particle size distribution, functional groups and magnetic properties of the NCMP and NCMP@MgFe-Zr particles were confirmed by various characterization analysis. The observed results clearly demonstrates that the NCMP@MgFe-Zr with the optimized composition remained stable during the removal experiments and enabled the removal of P under the conditions of acidic pH and relatively high P concentration without LDH dissolution. [Display omitted] •Particle weight loss increased with the increasing LDH content during the P removal.•The NCMP@MgFe-Zr particle showed excellent stability up to a LDH content of 60%.•All the other examined particles showed poor stability at all examined LDH contents.•Efficiency of magnetic separation increased with the increasing NCMP content.•Relatively high P removal performance was achieved under acidic pH condition.