Synthesis of recyclable magnetic attapulgite for purifying oily wastewater

Magnetically functionalized attapulgite (ATP) was synthesized by loading Fe3O4 onto ATP via co-precipitation method. The surface functional groups, thermal stability, microstructure, morphol-ogy, and magnetic properties of the samples were measured by Fourier-transform infrared spectros-copy, thermogravimetric analysis, X-ray diffraction, scanning electron microscope and vibrating magnetometer, respectively. The oil removal and recovery of magnetic ATP for oil-in-water emulsion was investigated. The results show that the magnetic ATP exhibits a saturation magnetization Ms of 1.5 emu/g, the coercivity Hc of 10 Oe and the residual magnetization Mr of 0.03 emu/g. In addition, the thermal stability and the dispersibility in oil-water emulsion of ATP is significantly improved by Fe3O4 modification. The adsorption capacity of ATP for emulsified oil slightly decreases from 8.14 to 7.16 mg/g after Fe3O4 modification, regardless of the effect of acid treatment or increment of loading amount. In particular, the modified ATP is easily recovered by an external magnetic field.

Automated summary

Magnetically functionalized attapulgite (ATP) was synthesized by loading Fe3O4 onto ATP, and the modified ATP showed improved thermal stability and dispersibility. The adsorption capacity of ATP for emulsified oil slightly decreased after Fe3O4 modification, but it could be easily recovered by an external magnetic field.