In this study, the application of two magnetic hydroxyapatite nanorods Sr5(PO4)3(OH)/Fe3O4 and Sr5xBa3x(PO4)3(OH)/Fe3O4, called SPF and SBPF for short, was investigated as effective adsorbents for removal of methyl blue (MB) from aqueous solution. Effects of three influence parameters (i.e., pH, temperature, and adsorbent dosage) were studied to optimize the adsorption processes. Kinetic data for both materials fitted well with pseudo-second-order kinetic model. The isotherm data agreed well with Langmuir model for SPF and Freundlich model for SBPF. The maximum adsorption capacity of SBPF nanorods (702mg/g) is higher than that of SPF (531mg/g), suggesting higher potential for MB removal. Thermodynamic studies indicated the adsorption process by these nanorods was spontaneous and exothermic. Moreover, these magnetic adsorbents can be easily recovered, and the capacity was maintained over 86% of the initial capacity after being used for five cycles. Mechanistic studies indicate that there are hydrogen bonding for MB-adsorbed SPF; whereas both hydrogen bonding and ionic interaction for MB-adsorbed SBPF. Interestingly, these magnetic nanorods show not only high adsorption capacity for MB but also facile regeneration from aqueous solution.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of the Taiwan Institute of Chemical Engineers|
|State||Published - Aug 1 2016|
Bibliographical noteFunding Information:
This work was financially supported by the National Natural Science Funds of China (Grant No. 51402153) and the Fundamental Research Funds for the Central Universities (Grant No.KJQN201553).
© 2016 Taiwan Institute of Chemical Engineers.
- Kinetic and isotherm models
- Magnetic nanorods
- Methyl blue