For　practical　applications　of　supercritical　water　oxidation　to　wastewater　treatment,　the　deposition　of　inorganic　salts　in　supercritical　phase　must　be　controlled　to　prevent　a　reactor　from　clogging.　This　study　investigated　enhanced　removal　of　sodium　salts　with　titanium　particles,　serving　as　a　salt　trapper　and　a　catalyst　precursor,　and　sodium　recovery　by　sub-critical　water.　When　Na2CO3　was　tested　as　a　model　salt,　sodium　removal　efficiency　was　higher　than　theoretically　maximum　efficiency　defined　by　Na2CO3　solubility.　The　enhanced　sodium　removal　resulted　from　in-situ　synthesis　of　sodium　titanate,　which　could　catalyse　acetic　acid　oxidation.　The　kinetics　of　sodium　removal　was　described　well　by　a　diffusion　mass-transfer　model　combined　with　a　power　law-type　rate　model　of　sodium　titanate　synthesis.　Titanium　particles　showed　positive　effect　on　sodium　removal　in　the　case　of　NaOH,　Na2SO4　and　Na3PO4.　However,　they　had　negligible　effect　for　NaCl　and　negative　effect　for　Na2CrO4,　respectively.　More　than　99%　of　trapped　sodium　was　recovered　by　sub-critical　water　except　for　Na2CrO4.　In　contrast,　sodium　recovery　efficiency　remained　less　than　50%　in　the　case　of　Na2CrO4.　Reused　titanium　particles　showed　the　same　performance　for　enhanced　sodium　removal.　Enhanced　salt　removal　supported　by　in-situ　catalyst　synthesis　has　great　potential　to　enable　both　salt　removal　control　and　catalytic　oxidation.