Dye removal using iron–polyphenol complex nanoparticles synthesized by plant leaves

• Iron–polyphenols complex nanoparticles (Fe–P NPs) were used as flocculant.
• The Fe–P NPs are more effective to remove dye than traditional flocculant FeCl3.
• The Fe–P NPs can be applied in water treatment due to its low toxicity and cost.
• This article indicated that many plants can produce this type of Fe–P NPs.

This paper examined the ability of iron–polyphenol complex nanoparticles (Fe–P NPs) synthesized by eucalyptus leaf extracts as a novel adsorptive flocculant to remove acid black 194 from aqueous solution. The influential parameters such as ratios of reagents, doses of Fe–P NPs, pH, temperatures and initial dye concentration were tested. The kinetics, experimental equilibrium and thermodynamic data for acid black 194 and Fe–P NPs systems were collected. The adsorption of dye on Fe–P NPs appears to be a physical process. This study confirms that removal of dye utilizing Fe–P NPs is more efficient than using traditional inorganic flocculant FeCl3. The Fe–P NPs could be employed as inexpensive and low-toxic adsorptive flocculant for removing dye from water.