## 4 Conclusions  
This study comprehensively evaluated the potential of Zr-EPRC particles as an effective solution for phosphorus removal in wastewater treatment. Through systematic experimentation and analysis, several key findings and conclusions have been drawn, shedding light on the suitability and optimization of Zr-EPRC particles in practical applications. Modification Methods Comparison: The investigation into different modification approaches for EPRC particles unveiled that each method improved phosphorus removal compared to the unmodified EPRC. However, direct modification yielded limited enhancement, co-modification raised concerns of surface chalking, and separate substrate modification resulted in Zr-EPRC particles characterized by both stable performance and simplified manufacturing processes. Consequently, the separate substrate modification approach emerged as the most promising method. Optimal Preparation Conditions: Crucial insights were gained concerning the optimal conditions for Zr-EPRC particle synthesis. These conditions included a precise mass ratio of zirconium chloride octahydrate to fly ash and steel slag (0.4 and 0.6, respectively), a pH of 10, and a loading time of 12 h at a constant temperature. Figure 20: Effect of coexisting ions on phosphorus removal effect of Zr-EPRC particles. adsorption Isotherms and Kinetics: This study determined that the Langmuir model better described the adsorption isotherms for phosphorus in Zr-EPRC particles. This indicated a significant enhancement in the adsorption capacity compared to the original EPRC material. Additionally, the quasi-secondary kinetic model provided a more accurate representation of the adsorption kinetics. Dosage and pH Impact: The results revealed a positive correlation between the effectiveness of phosphorus removal by Zr-EPRC particles and the dosage. A lower ambient pH for adsorption conditions was identified as favorable for phosphorus removal due to the prevalence of the H\({}_{2}\)PO\({}_{3}\)\({}^{-}\) form. The ambient pH for adsorption is different from the loading solution pH. The ambient pH for adsorption affects phosphate speciation and surface reactivity. The loading solution pH mainly affects the form of zirconium present on the adsorbent material and the pore size of the material. Resistance to Interference: Zr-EPRC particles exhibited robust resistance to interference from co-existing ions in water. This characteristic underscores their potential for effective deployment in complex sewage treatment scenarios. The study introduces a novel approach by utilizing zirconium oxychloride octahydrate-modified materials to prepare Zr-EPRC, contributing to an enhanced adsorption and phosphorus removal efficiency. The observed increase in both the surface area and average pore size in Zr-EPRC, compared to the previous EPRC results, signifies a substantial improvement. Specifically, Zr-EPRC exhibits a surface area that is 12.39 times that of the original EPRC and an average pore size that is three times larger. These significant enhancements underscore the material's promising capability for efficient phosphorus removal through adsorption. This noteworthy advancement adds valuable insights to the existing literature on enhanced phosphorus removal materials. In summary, this investigation underscores the substantial promise of Zr-EPRC particles, particularly when prepared via separate substrate modification, for addressing phosphorus pollution in wastewater treatment. Their exceptional adsorption characteristics, stability, and resilience to interference make them a highly viable solution for a wide range of practical wastewater treatment applications. This study offers valuable insights for optimizing the implementation of Zr-EPRC particles in real-world wastewater treatment processes, highlighting their potential significance in addressing phosphorus-related environmental challenges. Conceptualization, Y.L. and J.S. ; methodology, Y.L. and J.S. ; software, J.S. ; validation, Y.L. and J.S. ; formal analysis, J.S.