Synthesis of nano-β-CD@Fe3O4 magnetic material and its application in ultrasonic treatment of oily sludge.

Abstract

The extraction process of Tarim oil field in Xinjiang is accompanied by a large amount of oily sludge generation, which seriously restricts the progress of oil and gas development and causes serious pollution to the environment due to its large production, complex composition, and difficult treatment. Nanomaterials combined with ultrasound have been demonstrated to be a promising method for the disposal of hazardous oily sludge. In this paper, a magnetic material Nano-β-CD@Fe3O4 was prepared by hydrothermal method and surface modification method. Nano-β-CD@Fe3O4 can be intelligently enriched at the oil-water interface and oil-solid interface, and it can be stably dispersed to form nanofluid under the action of ultrasound. Nano-β-CD@Fe3O4 can cause changes in oil composition when it is exposed to ultrasound, resulting in the decrease of viscosity and increase of fluidity. The experimental results of treating oily sludge in Xinjiang Tarim showed that the best treatment effect was achieved when the concentration of Nano-β-CD@Fe3O4 was 0.5%, the ultrasonic frequency was 60Hz and the temperature was 60℃. This solution can reach 90.17% oil removal efficiency within 45min, and the secondary oil removal efficiency of Nano-β-CD@Fe3O4 recovered by magnetic separation could still reach 85.65%. This efficient oily sludge treatment method proposed in our study provides valuable information for the development of oily sludge treatment technology.