An osmotically driven membrane process was proposed for seawater pretreatment in a multi-stage flashing (MSF) thermal plant. Brine reject from the MSF plant draw solution (DS) forward osmosis (FO) order to reduce chemical use. The purpose of FO is removal divalent ions prior desalination. In this study, at 80 g/L and 45 concentrations were used as brine seawater, respectively. temperature 40 °C...