Dynamics of phosphate (PO₄³⁻) adsorption, desorption and regeneration characteristics of three lab-synthesized iron oxides, ferrihydrite (F), goethite (G), and magnetite (M) were evaluated in this study. Batch experiments were conducted to evaluate the impact of several adsorption parameters including adsorbent dosage, reaction time, temperature, pH, and ionic strength. The results showed that PO₄³⁻ adsorption increased with reaction time and temperature while it decreased with an increase in solution pH. Adsorption isotherm data exhibited good agreement with the Freundlich and Langmuir model with maximum monolayer adsorption capacities of 66.6 mg·g⁻¹ (F), 57.8 mg·g⁻¹ (M), and 50.5 mg·g⁻¹ (G). A thermodynamics evaluation produced ΔG < 0, ΔH > 0, and ΔS > 0, demonstrating that PO₄³⁻ adsorption onto tested minerals is endothermic, spontaneous, and disordered. The PO₄³⁻ removal mostly occurred via electrostatic attraction between the sorbate and sorbent surfaces. Moreover, the PO₄³⁻ sorption was reversible and could be desorbed at varying rates in both neutral and alkaline environments. The good desorption capacity has practical benefits for potential regeneration and re-use of the saturated particles in wastewater treatment systems.

本研究评估了三种实验室合成的氧化铁，三水铁矿（F），针铁矿（G）和磁铁矿（M）对磷酸盐（PO ₄ ^3-）的吸附，解吸和再生特性的动力学。进行批处理实验以评估几个吸附参数的影响，包括吸附剂量，反应时间，温度，pH和离子强度。结果表明，PO ₄ ^3-的吸附量随反应时间和温度的升高而增加，而随溶液pH的升高而降低。吸附等温线数据与Freundlich和Langmuir模型显示出良好的一致性，最大单层吸附能力分别为66.6 mg·g ^-1（F），57.8 mg·g ^-1（M）和50.5 mg·g ^-1（G）。热力学评估得出ΔG<0，ΔH> 0和ΔS> 0，表明PO ₄ ^3-在被测矿物上的吸附是吸热的，自发的和无序的。PO ₄ ^3-的去除主要是通过被吸附物和吸附剂表面之间的静电吸引来实现的。此外，PO ₄ ^3-的吸附是可逆的，并且在中性和碱性环境下都可以不同速率解吸。良好的解吸能力对废水处理系统中饱和颗粒的潜在再生和再利用具有实际的好处。