Notice of RetractionSorption Equilibrium and Kinetic Studies of Cu(II) from Wastewater with Modified Sepiolites

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.

The presenting author of this paper has the option to appeal this decision by contacting TPII@ieee.org.

This study focused on the characteristics of the removal of Cu(II)(Cu²⁺) from wastewater with sepiolites, a kind of natural mineral materials. The influences of pH, sorption time and adsorbent dose(the effect of temperature on the removal and sorption capacity is negligible in the test) were investigated in batch experiments, and the removal of Cu²⁺ and sorption capacity with modified sepiolites(MSs) were compared to those with original sepiolites(OSs). With the initial Cu²⁺ concentration 50 mg/L at pH 10, the removal of Cu²⁺ was 93.6% in 5h with 40g/L MSs by 0.8M HCI solution. The equilibrium process was described well by the Langmuir isotherm model with maximum sorption capacities of Cu²⁺ on MSs. Good correlation coefficient was obtained for the pseudo second-order kinetic model. In the end, some tungsten mine wastewater containing low concentration of Cu²⁺ was treated by MSs. It could be proposed that MSs by 0.8M HCI are an effective adsorbent for the removal of Cu²⁺ from wastewater. Meanwhile, Our objective is to search a kind of low-cost adsorbent as a replacement for costly conventional methods of removing heavy metal ions(Cu²⁺) from wastewater with sepiolites, to improve the utilization ratio of sepiolites and to pursue a new approach for environmental protection and recycle treatment of mineral materials. Study on the associative methods for MSs and advanced treatment which should be strengthened will offer the theoret- cal foundation for the practical application.