Structural selective regulation of Fe₃O₄@C composite as adsorbent for removing different organic pollutants

ABSTRACT

Many wastewater treatment methods have been developed because large amounts of organic pollutants (OPs) entered into the water bodies and adsorption is one of the classic and important technologies. Recently, magnetic adsorbents have garnered extensive attention due to the high efficiency and distinctive recyclability. The control of their structures and surface properties is crucial. Here, the magnetite@carbon (Fe₃O₄@C) composite was prepared by coupling microreactor and pyrolysis reactor. The structures and surface properties of the Fe₃O₄@C were effectively adjusted by changing the pyrolysis temperature and Na₂CO₃ concentration. The Fe₃O₄@C composite prepared at 800°C of pyrolysis temperature with 1 mol·L⁻¹ of Na₂CO₃ concentration has lipophilicity and the highest adsorption capacity of 92# gasoline among those adsorbents, which is as high as 7.6 g·g⁻¹. The Fe₃O₄@C synthesized at 500°C with 1 mol·L⁻¹ of Na₂CO₃ concentration has hydrophilicity and the highest adsorption capacity of Rhodamine B and Methyl Blue. The saturated adsorption capacities are about 166 and 301 mg·g⁻¹, respectively. Fe₃O₄@C can be easily separated from wastewater and simply regenerated with less capacity loss after five cycles. The results show that the Fe₃O₄@C prepared by this method could be suitable for the removal of different OPs by adjusting the preparation conditions.

HIGHLIGHTS

• Magnetic adsorbents Fe₃O₄@C were prepared by coupling microreactor and pyrolysis reactor.

• Structure and property of Fe₃O₄@C were effectively controlled by adjusting reaction parameters.

• Fe₃O₄@C composite exhibits outstanding adsorption performances for different organic pollutants.

• Fe₃O₄@C composite shows excellent recyclability and reusability.

• The adsorption kinetics fitted the pseudo-second-order model.

KEYWORDS:

• Magnetite@carbon composite
• magnetic adsorbent
• wastewater treatment
• adsorption
• organic pollutant

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplemental data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/01496395.2024.2366904.