Evaluation of polyvinylpyrrolidone as draw solute for desalination forward osmosis systems

In this study, polyvinylpyrrolidone (PVP) was evaluated as a potential draw solute for desalination forward osmosis (FO) systems. The effect of various draw solute and draw solution parameters on the efficiency of FO operation was investigated, including PVP molecular weight, PVP concentration in solution, and the salinity of feed solution. Experiment results showed that at draw solution initial concentration of 200 g/L and feed solution initial salinity up to 15 g/L, the PVP-based draw solution can offer water flux up to 14.23 LMH in FO mode with raw material cost only at 0.61 USD/m3. PVP K17 was proven to be an effective draw solute for FO systems, providing good water flux and low reverse draw solute flux; while also being relatively non-toxic, non-corrosive, cheap and widely available compared to other types of novel draw solutes.