Fabrication of polystyrene/CuO@calcined layered double hydroxide microspheres with high adsorption capacity for Congo red

Adsorption is gaining popularity as an efficient, fast, and low-cost method for the removal of organic dyes in the wastewater treatment. In this work, a novel inorganic-organic adsorbent, polystyrene/CuO/calcined layered double hydroxide (PS/CuO@CLDH) microspheres, was successfully fabricated through the dispersion polymerization method for the efficient removal of Conon red (CR). The structure of the microspheres of products was characterized, and the marked impact of key variables (e.g., adsorbent dosage, pH, contact time, and initial dye concentration) on its adsorption was investigated. PS/CuO@CLDH10 exhibits the highest adsorption capacity compared with other composite materials, in which the adsorption capacity can reach 484.6 mg g−1 when the addition amount is 10 mg. Furthermore, the dynamics and isotherms fit better with the pseudo-second-order and Freundlich model. The adsorption thermodynamic data illustrate that the adsorption process of PS/CuO@CLDH10 on CR is endothermic, spontaneous, and thermodynamically feasible. Moreover, PS/CuO@CLDH10 maintains high removal efficiency and structural composition after four cycles, revealing its excellent recyclability and stability. Therefore, this work provides a novel idea for designing and fabricating inorganic-organic composites for efficient adsorption in wastewater treatment. [Display omitted]