Highly efficient removal of phosphate by lanthanum modified nanochitosan-hierarchical ZSM-5 zeolite nanocomposite: characteristics and mechanism

چکیده مقاله

In this study, nanochitosan-hierarchical ZSM-5 zeolite composite (NCS@ZSM-5-H) was synthesized via simple way at ambient temperature. The hierarchical ZSM-5 zeolite were prepared by hydrothermal processing without the use of zeolite seeding crystals or additional template. Lanthanum (La) was loaded onto the surface of samples to acquire a simply separable adsorbent for efficient separation of phosphate (P) from water. The synthesized materials are examined before and after adsorption of P by several characterization techniques. Results of adsorption experiments showed that NCS@ZSM-5-H/La is very effective in the adsorption of P species from aqueous solutions. Response surface methodology has been applied to optimize and model P uptake onto NCS@ZSM-5-H/La nanocomposite. A four-factor central composite design has been applied to find out the influence of different process parameters on P removal. Thermodynamic, isotherm, and kinetic studies were employed to understand the adsorption behavior. The P adsorption was not significantly by interfering anions of fluoride chloride, and sulfate but carbonate revealed further negative effects, indicating NCS@ZSM-5-H/La possessed highly selectivity to P. The NCS@ZSM-5-H/La was regenerated using 2.0 M NaOH, with up to ~ 80% recovery and the as-synthesized nanocomposite was reused in seven consecutive adsorption–desorption cycles without significant reduction in regeneration capacity. © 2020, Springer Nature B.V.