Evaluation of Pervaporation and Nanofiltration Membranes for Water Recovery From Thermo‐Responsive Draw Solution

ABSTRACT Hybrid desalination processes have gained attention for overcoming limitations of conventional membrane desalination. Forward osmosis (FO) systems using thermo‐responsive polymer draw solutions are considered promising. In this work, the feasibility for water recovery from a thermo‐responsive block copolymer solution (PAGB2000) was investigated using pervaporation (PV) and nanofiltration (NF) membranes. Performance was evaluated on the basis of water flux and PAGB2000 retention. Experiments were conducted below and above the lower critical solution temperature of PAGB2000. Higher feed temperatures increased water flux for both PV and NF membranes, whereas PAGB2000 retention ranged from 98.0% to 99.6%. The results demonstrate the potential of both technologies for water recovery in hybrid FO systems.