Background: Arsenic (AS) is a heavy metal pollutant in water that has been known as one of the
most important environmental contaminants due to its serious effects on both human health and the
environment. This study was conducted to investigate the efficiency of calcined Co/Fe/Al LDH@Fe3O4@
PA as a new magnetic bio-sorbent for AS removal from the polluted water.
Methods: At first, magnetic ternary calcined layered double hydroxide (Co/Fe/Al LDH) was synthesized
through co-precipitation procedure. The synthesized CLDH was modified with phenylalanine amino
acid, named CLDH@Fe3O4@PA. Infrared spectroscopy, X-ray diffraction, transmission, and field
emission scanning electron microscopy (FESEM) were used to confirm the synthesis of the sorbent. The
removal time, pH, and the sorbent dose were studied and optimized as the effective parameters on the
As (V) removal.
Results: The XRD, FTIR, TEM, SEM, EDS, and VSM techniques confirmed the properties of the
synthesized magnetic bio-sorbent. Based on the optimization study, pH=6, the sorbent concentration of
30 mg, and the removal time of 5 minutes were considered as the optimum conditions with about 91%
AS removal. The Langmuir isotherm with higher R2 value was matched well with the obtained results,
and values obtained for qm and RL were 167 mg g–1 and 0.976 to 0.993, respectively. The kinetics studies
were fitted well with the linear pseudo-first-order model with higher R2 at sorption process.
Conclusion: The real samples results confirmed the excellent As (V) sorption capacity of the synthesized
magnetic bio-sorbent in comparison with other sorbents. Therefore, CLDH@Fe3O4@PA sorbent is
introduced as a new suitable sorbent for removal of As (V) from the polluted water.
Keywords: Water pollution, Phenylalanine, Ferrosoferric oxide, Arseni
