Effect of the modification of magnetic graphene oxide with ionic liquid on the adsorption of nonionic surfactant NP10EO

The large-scale application of ionic surfactants in industrial and agricultural production has caused great harm to the environment due to by-products. In order to remove this pollutant from the environment, graphene oxide as an adsorption material has received extensive attention. However, practically, it is difficult to separate the GO from aqueous solutions, making water treatment on a large scale challenging. To allow the recycling of GO, as well as enhance its adsorption ability to remove surfactants from water, a composite of magnetic graphene oxide (MGO) and 1-dodecyl-3-methylimidazolium chloride ionic liquid (IL) was synthesized. The MGO was prepared by coprecipitation, and IL-MGO was prepared by ultrasonic impregnation. Nitrogen adsorption-desorption curves show that the specific surface area of the composite was increased by the addition of the IL, from 103.28 to 163.35 m2/g. Finally, the adsorption ability of MGO and IL-MGO for the nonionic surfactant NP10EO was investigated. The results showed that the adsorption of MGO on NP10EO fits the Langmuir isothermal model and the quasi-second-order kinetic model. In addition, the equilibrium adsorption capacity of NP10EO by MGO at 298K, 308K, and 318K can reach 87.03 mg/g, 156.25 mg/g, and 214.13 mg/g. The adsorption is an endothermic reaction that occurs spontaneously and is governed by physical adsorption. The adsorption of IL-MGO on NP10EO conforms to the Langmuir isotherm model and the quasi-second-order kinetic model. At 298K, 308K, and 318K, the equilibrium adsorption capacity of NP10EO by MGO reached 261.02 mg/g, 280.24 mg/g, and 295.03 mg/g, respectively. Compared with the two results, the incorporation of IL greatly improved the adsorption capacity of MGO to NP10EO.