The demand to recover value-added resource is intensified due to the accelerating growth of resource waste with wastewater discharge. Here we design pH-responsive sodium salts of an imidazole-based ionic solid (im-IS), im-IS-Na and im-IS-2Na, as draw solutes for forward osmosis (FO) to achieve resource recovery. im-IS-Na and im-IS-2Na both have an expanded structure and contain multiple ionic moieties. These attributes make them generate a sufficient driving force for FO separation and negligible solute losses. Consequently, im-IS-Na and im-IS-2Na at 1.0 M produce pure water fluxes of 27.5 LMH and 32.0 LMH, respectively, increased up to 128 % relative to those of conventional draw solutes. im-IS-Na can concentrate the glycine-containing solution efficiently with a water flux of 17.6 LMH, 183 % and 25 % higher than those of NaCl and NH4HCO3, separately. Particularly, im-IS-Na preserves the glycine product intact, whereas NaCl and NH4HCO3 either denature or contaminate it resulting from their severe reverse diffusion. im-IS-Na and im-IS-2Na are conveniently regenerated by pH regulation involving no organic solvent and external pressure which are commonly used in recycling other draw solutes. im-IS-Na and im-IS-2Na thus demonstrate their superiority as FO draw solutes to recover value-added resources.