Notice of RetractionStudy on Removal of COD in Secondary Effluent by Enhanced Coagulation

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.

With the secondary effluent from a steel and iron industry wastewater treatment as the object of study, the effects of enhanced coagulation on the removal rate of COD in secondary effluent by different flocculants were investigated, the results showed that the removal rate of COD decreased from 128mg/L to 82mg/L when potassium ferrate and calcium hydroxide were used together as flocculants; according to debugging results in the worksite, the optimal concentration of potassium ferrate and calcium hydroxide for wastewater treatment capacity of 700~800m3/d were determined as followings: potassium ferrate 12.5mg/L, calcium hydroxide 4.17mg/L, the remove rate of effluent COD could reach the discharge standard of 100mg/L when the mass concentration of COD in the influent wastewater was 100~150mg/L.