以可溶性淀粉为改性剂,采用氧化沉淀法分别制备了可溶性淀粉改性Fe3O4以及纯Fe3O4,并研究了2种Fe3 O4粒径、表面性质以及除磷效能的差异。实验结果表明,淀粉改性使得纳米Fe3 O4粒径减小,粒径由60 nm减小到10nm左右;红外和Zeta电位结果表明淀粉在Fe3 O4粒子表面是化学吸附;2种纳米Fe3 O4对磷的吸附量均随pH的升高而降低;吸附等温线符合Freundlich方程,淀粉改性Fe3O4吸附能力高于纯Fe3O4,吸附常数K由2.58 L/g提高到3.45 L/g;整个吸附过程以较快的速度进行,1.5~2 h内吸附反应基本完成,准二级动力学模型能够很好地描述吸附动力学过程。
Starch-coated and bare Fe3O4 were prepared by the oxidation deposition method,and the difference of particle size,surface character,and adsorption capability between these two types of Fe3O4 was further studied.Results showed that particle size of Fe3O4 decreased from 60 nm to 10 nm after modified by soluble starch.FTIR spectroscopy and Zeta potential analysis indicated that there was chemical bonding between soluble starch and Fe3O4.The adsorbed amounts of phosphate decreased with the increase of pH for both bare Fe3O4 and starch-coated Fe3O4.Freundlich equation showed more applicability than Langmuir equation,and starch-coated Fe3O4 had higher adsorption capability than bare Fe3O4.The majority of phosphate adsorption was completed in 1.5~2 h,and the adsorption kinetics could be best described by pseudo second-order equation.