Utilization and treatment of phosphogypsum: Environmental impacts and resource potential

With the phosphate fertilizer industry expanding to meet rising global demand, it generates substantial quantities of phosphogypsum (PG), a by-product with complex composition. The environmental challenges associated with long-term PG storage are becoming increasingly severe. This paper reviews the research progress and future prospects of PG from three perspectives: its compositional characteristics, pretreatment technologies and utilization. The Physicochemical characterization of PG are presented, and the correlations between various impurity components and application pathways are summarized. The characteristics and application scenarios of PG pretreatment technologies are discussed. Physical, chemical, and thermal treatment methods are found to be inadequate in impurity removal and associated with high costs. Biowashing method is recognized as a green approach with significant potential for impurity removal, and the development of "microbial-enzyme synergy" technologies and screen acid-resistant strains is required to balance cost reduction and safety. The current applications and limitations of PG in construction industry, agriculture, chemical industry and environment are summarized. Critical challenges include impurity-induced restrictions and the necessity for rigorous safety assessments in short-term (highway engineering) and long-term (artificial soil) large-scale applications. Finally, future research directions are proposed: screening acid-tolerant microorganisms, recovering high-value elements with low carbon emissions, evaluating the long-term performance of road materials, and optimizing the ecological safety of artificial soils. These efforts aim to promote the green treatment, efficient utilization and ecological recycling of PG.