The high concentration of fluoride and phosphate in phosphogypsum leachate is harmful to the environment and ecosystem. Thus, there is a need to develop feasible materials or technologies to remove both fluoride and phosphate in acidic phosphogypsum leachate. In this study, sulfoaluminate cement (SC) was used to simultaneously remove fluoride and phosphate in wastewater based on its moderate alkalinity and rich content of metal ions. The acidized sulfoaluminate cement (ASC) composite was prepared through simple acidizing modification, which can increase the specific surface areas of the raw SC and activate the activity of the metal ions in SC. Compared with other coagulants, ASC showed excellent removal performance for fluoride and phosphate, such as higher removal efficiency, better water quality, and faster settling rate. The fluoride and phosphate removal performances of ASC were investigated at different dosages, pH values, coexisting anions, and initial concentrations. And ASC exhibited wide pH adaptability and satisfactory selectivity for fluoride and phosphate. The addition of ASC increased the pH value of the reaction system, which provided a friendly environment to generate stable precipitates between the anion contaminates and the metal ions in ASC. On the basis of the characterization analysis, the possible removal mechanism of fluoride and phosphate by ASC included chemisorption, ion exchange, and precipitation. The main products of fluoride removal were CaF₂, AlF₃, and FeF₂, and the main products of phosphate removal were CaHPO₄·2H₂O, (H₃O)·AlP₂O₆(OH)₂, Ca₂SiO₄·Ca₃(PO₄)₂ and Fe₃(H₂PO₄)₃. More importantly, ASC can effectively treat the phosphogypsum leachate at different concentrations, and the concentrations of fluoride and phosphate in effluents can constantly meet the current discharge standard of phosphorus chemical wastewater. To conclude, ASC composite has great potential for fluoride and phosphate wastewater treatment, especially for phosphogypsum leachate
