Utilization of waste cation exchange resin to prepare carbon/iron composites for the adsorption of contaminants in water

• Waste cation exchange resin was employed as the precursor of the composites.
• Activation temperature had a significant impact on the composite properties.
• The optimized product featured a large surface area and strong magnetic property.
• The magnetic properties of the composites were related to their crystal structures.
• The optimized product exhibited high stability over the pH range of 4–11.5.

Carbon/iron composites were prepared from waste cation exchange resin by NaOH activation. The BET surface areas were over 1200 m2 g−1. The presence of iron led to the formation of new mesopores and macropores. Activation temperature had a significant impact on the pore size distributions, crystal structures, and magnetic properties of the carbon composites, and the magnetic properties of the composites were related to their crystal structures. The composite synthesized at 800 °C (800ACS-1) could effectively remove diethyl phthalate, bisphenol A, and malachite green from aqueous solutions. 800ACS-1 also exhibited high stability over a wide pH range of 4–11.5.