Adsorption Behavior of a Core‐Shell Microsphere Material Polymethyl Methacrylate/Sodium Montmorillonite on Organic Dye Congo Red and Copper Ions in Wastewater

Abstract With the rapid advancement of industrialization and urbanization, economic growth has accelerated, leading to a dramatic increase in industrial and mining wastewater. Therefore, the research of adsorbent materials for the simultaneous removal of organic dyes and metal ions from wastewater has become the focus of current environmental studies. In this study, polymethyl methacrylate/sodium montmorillonite composite microspheres (PMMA‐Na‐MT) with core‐shell structure were prepared using methyl methacrylate as the reaction monomer, azodiisobutyronitrile as initiator, gelatin as protective colloid, sodium montmorillonite as core material, and polyethylene glycol as template. FTIR, XRD, and other tests characterize the structure of microspheres, and their adsorption behavior on Congo red and Cu 2+ was investigated, respectively. The composite microspheres showed excellent adsorption capacities of 355.5 mg/g for Congo red and 215.6 mg/g for Cu 2+ . The adsorption process is dominated by quasi‐second‐order kinetics. The adsorption isotherm follows the Langmuir model, indicating that the adsorption process is characterized by monolayer adsorption. The successful preparation of PMMA‐Na‐MT solves the problem of difficult solid–liquid separation in Na‐MT adsorption alone, while also achieving pore formation in PMMA microspheres without the use of pore‐forming agents. Moreover, it provides a new approach for the treatment of multicomponent industrial wastewater.