Modeling water coagulation processes with K₂FeO₄ using central composite design

This study analyzes the efficiency of water coagulation using potassium ferrate (VI) (K 2 FeO 4 ) and iron (III) chloride (FeCl₃). Water from the Biała-Nida river (Swietokrzyskie voivodeship) did not meet regulatory standards for color and oxidisability. A vessel test method was used with 16 different doses of each coagulant, evaluating COD, color, and UVA(254). The best treatment effects were obtained at a dose of potassium ferrate (VI) equal to 8.17 mg L −1 and pH = 5.4, after 17 minutes of water coagulation using K 2 FeO 4 it was possible to reduce the color from the initial value of 50 mgPt L −1 to 5 mgPt L −1 . This means that 90 % of the solution color was removed in the process. The highest efficiency (almost 63 %) in terms of removing UVA(254)-absorbing substances from the water was also achieved for this trial. The best COD elimination results are 65 %. A mathematical model was developed using DOE in Statistica 12, streamlining the process. Findings confirm potassium ferrate (VI) as a promising alternative to traditional oxidants, potentially improving water treatment methods.