碳酸钙复合材料的制备及其对Fe3+的吸附研究OA

This study aimed to investigate the influence mechanisms of dopamine(DA)and sodium alginate(SA)as regulating agents on the structure of calcium carbonate composites and their adsorption performance for Fe3+.By adjusting the concentrations of DA and SA,the regu-latory effects on the crystal phase,microstructure,and particle size distribution of calcium carbonate were systematically studied,and the ad-sorption performance and cycling stability of the two composites for Fe3+were compared.The results showed that the adsorption behavior of DA-CaCO3 conformed to the Freundlich isothermal adsorption model,indicating its heterogeneous surface and adsorption dominated by multi-layer physisorption and weak chemical interactions with Fe3+.In contrast,SA-CaCO3 better followed the Langmuir isothermal adsorption mod-el,suggesting relatively uniform surface sites and a monolayer chemisorption process dominated by chelation,with a theoretical maximum ad-sorption capacity of 515.36 mg/g.Cycling experiments further showed that SA-CaCO3 maintained a removal rate above 80%towards Fe3+after 5 times of adsorption-desorption cycles,demonstrating a good regeneration stability.