Fig. 4: Simulations performed by PHQREEC software for real solution.

Simulated saturation index (SI) versus concentration factor (CF) for real wastewater at 31 °C (A, D), 44 °C (B, E) and 49 °C (C, F), before (A–C) and after (D–F) the basic treatment of the feed solution. The vertical lines show the concentration factor at the endpoint of the MAC tests. The shaded areas highlight the negative SI region. For simplicity, curves with SI < −1 are not shown.