Notice of RetractionRemoval of Lead(II) Ion from Waste Water by Composite Modified Maifan Stone

Notice of Retraction

After careful and considered review of the content of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE´s Publication Principles.

We hereby retract the content of this paper. Reasonable effort should be made to remove all past references to this paper.

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Using natural maifan stone as a raw material, a kind of Pb²⁺ adsorption material was prepared by chemical and heat treatment composite modification method. The modified maifan stones were characterized by X-ray fluorescence spectrometer (XRF) and scanning electronic microscope (SEM). Moreover, the relationships between the absorption rates of Pb²⁺ with the maifan stone contents, contact time and the initial pH value of the lead nitrate solution were analyzed. The experiment results show that the composite modified maifan stone, which was prepared with heat treatment modification for 0.8 h at 380°C after the chemical modification for 24 h with 2 mol/L sodium chloride solutions, increased significantly in porosity, contact area and absorption properties of Pb²⁺. And then the adsorption rate of Pb²⁺ of the composite modified maifan stone was the best and up to 94.5%, at the condition of the initial Pb²⁺ concentration=50 mg/L, the pH value of the lead nitrate solution =6.0, the maifan stone content=45 g/L, and the contact time=35 min.