On the basis of the obtained laboratory results,
existing treatment plants could be upgraded including
the following treatment steps/phases:
• sodium hydroxide addition to raise the pH to
8.5;
• potassium permanganate addition (1.74 mg/L)
and rapid mix at mixing speed of 120 rpm for
2 min;
• slow mix at mixing speed of 30 rpm for 30 min,
addition of Polyelectrolite DF974 (0.5 mg/L)
and settling for 1 h;
• filtration by self cleaning tangential flow rotary
filters equipped with 35 μm membrane;