Abstract:

With rapid development of industrial technology, large amount of oily wastewater has been generated in the processes of oil exploitation, transportation, etc. Oily wastewater is characterized by large discharge, complex composition, and poor biodegradation. If it is discharged into the environment without proper treatment, it will cause great harm to human health and the ecological environment. In view of the current situations such as water scarcity, serious environmental pollution and increasingly stringent emission standards, how to deal with oily wastewater is one of the research hotspots in the field of water treatment. Magnetic flocculation is a new water treatment technology, which has been proven effective in the fields of turbidity reduction, phosphate removal, and organic compound removal. Therefore, magnetic flocculation shows great application potential in the field of water treatment. Herein, the research progress of magnetic flocculation in oily wastewater treatment was systematically reviewed. Firstly, the sources and characteristics of oily wastewater were introduced, and the classification of magnetic flocculation was presented. Then, the preparation of magnetic materials, the process conditions when applied in oily wastewater treatment, and the recycling of magnetic flocculants were specifically introduced. Moreover, the current research on magnetic flocculation in the field of oily wastewater treatment was briefly introduced. Finally, the development direction of magnetic flocculation was prospected from the aspects of magnetic materials, application range, multi-process coupling, etc., in the hope of a broader application in the treatment of oily wastewater.

Key words: coagulation, magnetic flocculation, wastewater, emulsion, oil-water separation