sCobalt ferrite nanoparticles (CoFe2O4 NPs) are used as an efficient adsorbent to remove cobalt (II) phthalocyanine (CoPc) dye from aqueous solutions. The characterization of adsorbent is investigated by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray spectroscopy (EDX), and the vibrating sample magnetometer (VSM) technique. To optimize the effective factors, response surface methodology (RSM) through using Box–Behnken design (BBD) is applied. By proper running of the Desirability function option in MINITAB software, the optimum conditions were found as pH 3.2, adsorbent mass (m) 11 mg, contact time of nine minutes (t), and initial dye concentration (Cd) of 30mg L1. Isotherm studies of the adsorption process are carried out where the Langmuir isotherm shows the maximum monolayer capacity (qmax) is 431 mg g1. The kinetic studies including pseudo-first-order, pseudosecond- order and intra-particle diffusion models indicate that the pseudo-second-order kinetic model describes better the adsorption kinetic behavior. This study shows that CoFe2O4 NPs have excellent potential for the removal of CoPc dye from an aqueous solution. Key words | adsorption, Box–Behnken design, cobalt ferrite nanoparticles (NPs), cobalt (II) phthalocyanine dye, response surface methodology (RSM)
