The synthesis of NdFeB magnetic activated carbon and its application in degradation of azo dye methyl orange by Fenton-like process

• NdFeB magnetic catalysts had been produced by negative pressure impregnating process.
• NdFeB magnetic catalysts had stable effect and reused feasibility in heterogeneous Fenton-like process.
• Under optimum conditions methyl orange degradation ratio could reach 97.1% after NdFeB magnetic catalysts was reused 5 times.

In this paper, the magnetic NdFeB-activated carbon Fenton catalyst (NdFeB-AC-FC) was synthesized by negative pressure impregnation method. The results of magnetite susceptibility measurement show that the NdFeB-AC-FC had hard magnetic properties. Its saturated magnetization, remanent magnetism and coercive force were 18.11 emu/g, 5.7 emu/g, and 905 Oe, respectively. The surface morphology and elementary composition test results show that the specific area and Fe content of NdFeB-AC-FC have been significantly improved by negative pressure impregnation treatment. The feasibility of the NdFeB-AC-FC as catalyst in heterogeneous Fenton-like process has been studied by degrading the simulated dye wastewater. The results show that the NdFeB-AC-FC not only had splendid catalytic activity, but also had reused feasibility in heterogeneous Fenton-like process. Under the optimum conditions ([methyl orange (MO)]0 = 20 mg/L, temperature = 20 °C, [NdFeB-AC-FC]0 = 10 g/L, [H2O2]0 = 0.6 mmol/L and pH = 3.0), MO degradation ratio also could reach 97.1% after 5 cycles. In addition, the results of kinetics study show that the catalytic degradation process follows the pseudo-first order kinetics model. In a word, the catalyst has a good application prospect and it could provide a new technique to solve organic industrial wastewater pollution.