Background: The pressing demand to increase agricultural productivity amid the rapidly growing population
has exponentially boosted fertilizers usage. Phosphate (Pi) runoff from fertilizers induces eutrophication in
water sources and severely affects its surrounding ecosystems. To cope with Pi accumulation problem, this
study reported the synthesis of an environmentally friendly magnetic adsorbent, namely Fe3O4/thiamine
(thF).
Method: A one-step chemical oxidation and functionalization technique for thF synthesis was developed.
X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy
(FTIR), nitrogen (N2) sorption, and superconducting quantum interference device (SQUID) analysis were conducted to ensure the formation of Fe3O4, confirm the successful incorporation of thiamine, and gain insight
into the factors influencing the adsorptivity of thF-363.
Significant Findings: The thF synthesized at 363 K (thF-363) produces an adsorbent with the highest Pi
removal efficiency compared to other synthesis conditions. The thF-363 showed up to 1.51-fold higher
adsorption capacity than the unmodified Fe3O4. The large surface area and occurrence of thiamine functional
groups are the contributing factors in enhancing its adsorption capacity for Pi removal. The thF-363 did not
adversely affect the growth of the model plant, Arabidopsis thaliana; demonstrating its suitability as an
environmentally friendly adsorbents for Pi removal from eutrophicated water with the feasibility of magnetic
separation from an aqueous system.