INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, cilt.51, sa.32, ss.10629-10640, 2012 (SCI-Expanded)
Magnetic poly(hydroxyethyl methacrylate-co-ethylene glycol dimethacrylate) (p(HEMA-EGDMA)) beads were synthesized via suspension polymerization. To prepare a novel core-shell type resin, the magnetic beads were grafted with poly(glycidyl methacrylate) (p(GMA)) via the surface-initiated atom transfer radical polymerization (SI-ATRP) method. The grafted p(GMA) fibrous chains on the magnetic beads were modified with nitrilotriacetate (NTA). The magnetic beads were characterized by FTIR, SEM, and VSM. The carboxyl group content of the p(HEMA-EGDMA-g-GMA)-NTA resin was found to be 9.63 mmol g(-1) of beads by the potentiometric titration method. The adsorption of Crystal Violet (CV) and Methylene Blue (MB) as basic dyes by the NTA-modified magnetic beads was investigated. The influence of different experimental parameters such as pH, contact time, and temperature on the removal process was evaluated The maximum adsorption capacity was found to be 230.1 and 1975. mg/g for CV and MB, respectively. The adsorption process was described by the Langmuir model more correctly. Adsorption studies of CV and MB onto NTA-modified magnetic beads were also carried out in a magnetically fluidized reactor, with different flow rates and initial dye concentrations.