Producing　clean　water　and　simultaneously　recovering　valuable　compounds　are　a　big　challenge　in　wastewater　treatment.　Here　we　designed　a　bifunctional　zwitterion　of　(1-(3-aminopropyl)imidazole)　propanesulfonate　(APIS)　for　membrane　modification　and　being　a　draw　solute　as　well　for　water　production　and　protein　enrichment　via　forward　osmosis　(FO).　Immobilized　to　the　membrane　surface　by　a　fast　amidation　reaction,　APIS　endows　the　membrane　with　favorable　properties　benefiting　the　FO　process.　The　APIS-modified　sulfonated　poly(ether　sulfone)　(APIS-sPES)　membrane　produces　a　water　flux　101%　higher　than　that　of　the　nascent　membrane　(from　9.3　to　18.7　LMH)　with　0.5　M　NaCl　as　the　draw　solution.　The　APIS-sPES　membrane　also　exhibits　higher　fouling　resistance　with　a　much　smaller　decline　in　water　permeation　and　stronger　renewability　with　the　flux　restored　to　88%　of　the　original　value　compared　to　a　59%　recovery　rate　of　the　nascent　membrane　after　20-h　experiments　against　a　200　ppm　ovalbumin　solution.　APIS　produces　a　fair　good　water　flux　coupled　with　negligible　reverse　diffusion　when　used　as　a　draw　solute　and　can　be　readily　regenerated　via　pH　regulation.　Unlike　the　conventional　NaCl　draw　solute,　APIS　does　not　contaminate　or　damage　protein　structure.　The　APIS-sPES　membrane　and　APIS　draw　solute　prove　a　perfect　match　in　protein-containing　wastewater　treatment　and　protein　enrichment.　©　2019　American　Chemical　Society.