Removal of Phosphate from Aqueous Solution With Fe-Mn Oxide Formed in Situ by KMnO4-Fe(II) Process

The removal of phosphate by KMnO4-Fe(II) process was investigated under different experimental conditions. The results showed that mix speeds and settling time had no significant effect on phosphate removal. The removal of phosphate was gradually increased with the increase of Fe dosages and decreased with the increase of pH. When the pH increased from 4 to 9, the removal of phosphate decreased from 97.1% to 41.6%. Compared with ferric sulfate, the KMnO4-Fe(II) process was more efficient for phosphate removal. The presence of turbidity had limited effect on phosphate removal at lower pH and resulted in a significant increase in phosphate removal at higher pH. The temperature had little effect on phosphate removal in KMnO4-Fe(II) process. With the presence of calcium, the removal of phosphate had a significantly increase. Silicate had negative effect on phosphate removal in KMnO4-Fe(II) process.