Notice of RetractionPhosphorous Precipitation/Recovery as Struvite from Wastewaters of Low Phosphorous Concentration

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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Optimizing the process of precipitation/recovery phosphorous as struvite (MgNH₄PO₄·6H₂O, MAP) from wastewaters with low phosphorous concentration and the validity of applying the chemical equilibrium modeling in Visual Minteq for predetermination the reaction products were investigated. Lab batch experiments with synthetic wastewater verified that the extended models in Visual Minteq could predict phosphorous behavior in simulating phosphorous recovery as MAP successfully. Results of the experiments and model simulations indicated that phosphorus recover efficiencies were highly dependent on pH values, dosage of amending ammonium and magnesium, and phosphorus content in wastewaters. The optimum pH for the process was 9. Amorphous bobierrite (Mg₃(PO₄)₂·8H₂O), other than struvite crystallite was prone to form in the process of precipitation or recover phosphorus with magnesium adding into wastewaters with total phosphorous (TP) lower than 60mg/L. Strategy of amending magnesium and ammonium dosage to achieve the initial molar ratio of Mg:N:P=1.5:2.0:1 was suggested to improve struvite recovery efficiency from the low-phosphorous-contained wastewaters.