Preparation and application of composite magnetic flocculants for wastewater treatment: A review

Wastewater treatment plays a vital role in protecting natural environments. Among the various wastewater treatment methods, flocculation achieves effective wastewater treatment, owing to its high efficiency, convenience, and cost-effectiveness. Compared to traditional flocculants, Composite magnetic flocculants have attracted significant attention due to their distinctive "core-shell" structure, magnetic flocculation mechanism and high efficiency recovery. This promotes sustainable development in wastewater treatment, highlighting the significant prospects for its application and potential advancement. This review begins by discussing the raw materials and treatment methods of composite magnetic flocculants and presenting common materials and associated preparation techniques. By combining the advantages of organic and inorganic components, disparate raw materials give flocculants different properties and flocculation efficiency. Through the comprehensive analysis of the flocculation mechanism, the flocculation efficiency of various wastewater treatment targets was elucidated, and the exceptional performance in overcoming steric hindrance was introduced. Subsequently, recycling approaches were summarized to determine the advantages and disadvantages in terms of recovery efficiency, operational difficulty, and impact on particle structure. Based on the current developmental status, this review provides a prospective outlook on future exploration trends in composite magnetic flocculants, valuable references, and theoretical foundations for related research and engineering practices.