采用活性微米铁/CaO 复合体系的 含磷废水应急处理研究

In order to address the urgent need for the treatment of phosphorus-containing wastewater within 40 seconds to avoid environmental risks, an active micron zero-valent iron(mZVI)is prepared by hydrogen peroxide-hydrochloric acid(H₂O₂-HCl)activation and combined with calcium oxide(CaO)to form a composite system. This system reduces the phosphorus concentration in wastewater to below 0.2 mg/L and maintains the pH value between 6 and 9(surface water class Ⅲ standard)within 40 seconds. Firstly, experiments are conducted separately by adding CaO and active micron iron. Subsequently, phosphorus-containing wastewater is treated using the active micron iron/CaO composite system, and its phosphorus removal mechanism is studied. Finally, stability tests are carried out, followed by continuous flow experiments under simulated field conditions. Experimental results show tha the combined addition of CaO and active micron iron can meet the surface water class Ⅲ standard for phosphorus in wastewater within 40 seconds H₂O₂-HCl accelerates the oxidation and corrosion of mZVI, providing active adsorption sites Fe3O4, effectively adsorbing phosphate ions and forming Fe-P compounds mainly composed of Fe2(PO4)3 and FePO4. Through chemical precipitation, CaO reacts with phosphates to produce Ca-P compounds, mainly Ca₅(PO₄)₃(OH), achieving an organic combination of chemical precipitation and adsorption. In stability tests lasting up to 28 days and continuous flow experiments, the phosphorus concentration and pH value of the treated wastewater remain stable after treatment with active micron iron/CaO, meeting the surface water class Ⅲ standard within 40 seconds. These research findings provide a theoretical basis for the emergency treatment of phosphorus-containing wastewater.