植物多酚功能化调控磁性材料磁絮凝高岭土悬浊液

Magnetic flocculation of kaolin suspension using magnetic materials functionally regulated with plant polyphenols

天然植物多酚(PP)作为功能化调控配体,通过原位自组装制备了Fe_(3)O_(4)@PP磁性复合材料,用于高岭土悬浊液的磁絮凝.采用SEM观察了Fe_(3)O_(4)@PP的形貌;研究了Ca^(2+)离子、碱度和腐殖酸浓度对Fe_(3)O_(4)@PP絮凝性能的影响.采用光学显微镜观察了磁絮体在生长和破碎过程中的形态和结构特征,通过扩展的DLVO理论探究了Fe_(3)O_(4)@PP和高岭土颗粒之间的相互作用机制.结果表明,Fe_(3)O_(4)@PP具有优异分散性、化学稳定性和絮凝性能,可以克服碱度和腐殖酸的干扰,实现96.4%的最大浊度去除效率.磁絮凝过程中,磁絮体会逐渐变得致密,并生成长链状聚集体,具有良好的抵抗破碎能力.相互作用能分析表明,磁力主导了整个絮凝过程,其总相互作用势能和作用范围要比静电力和范德华力高三个数量级.此外,pH值、Ca^(2+)离子浓度和离子种类也对总相互作用能有重要影响.

Plant polyphenol(PP)was used as a functional regulating ligand in preparation of Fe_(3)O_(4)@PP magnetic composite via in-situ self-assembly,which was applied in magnetic flocculation of kaolin suspension.The morphology of Fe_(3)O_(4)@PP was observed with SEM.The effects of Ca^(2+)ions,alkalinity,and humic acid concentration on flocculation performance of Fe_(3)O_(4)@PP were studied.The morphology and structural features of magnetic flocs during growth and breakage were observed using optical microscopy.The interaction mechanism between Fe_(3)O_(4)@PP and kaolin particles was investigated with the extended DLVO theory.The results showed that Fe_(3)O_(4)@PP had excellent dispersibility,chemical stability,and flocculation performance,which could overcome the interference of alkalinity and humic acid,achieving a maximum turbidity removal efficiency of 96.4%.During magnetic flocculation,magnetic flocs gradually became denser and formed long-chain aggregates with good resistance to breakage.The analysis of interaction energy indicated that magnetic force dominated the entire flocculation process.The total interaction potential and effective distance of magnetic force were three orders of magnitude higher than electrostatic and van der Waals forces.Furthermore,the total interaction energy was also affected by the properties of the suspension,such as pH value,Ca^(2+)ion concentration,and ion species.