Extensive　studies　have　been　carried　out　on　phosphate　removal　by　zero　valent　iron　(ZVI).　Different　mechanisms　of　phosphate　removal　by　ZVI　such　as　phosphate　adsorption　and　precipitation　of　ferric　phosphate　and　vivianite　(Fe3(PO4)2·8H2O)　have　been　reported.　In　this　study,　attenuated　total　reflectance-Fourier　transform　infrared　spectroscopy　(ATR-FTIR),　X-ray　powder　diffraction　(XRD),　and　X-ray　absorption　near　edge　spectroscopy　(XANES)　were　used　to　elucidate　the　mechanisms　of　phosphate　removal　by　micron-scale　zero-valent　(mZVI).　Time-series　ATR-FTIR　analysis　revealed　that　phosphate　was　removed　by　ZVI　in　two　steps:　a)　adsorption　of　phosphate　in　the　first　3　days,　and　b)　slow　conversion　of　the　adsorbed　phosphate　into　the　precipitated　form　in　6　days.　XRD　and　XANES　analysis　determined　that　iron　oxides,　ferric　ion,　and　ZVI　with　oxide　layer　inhibited　the　formation　of　vivianite,　resulting　in　the　formation　of　phosphate　precipitates,　such　as　H2Fe(II)P2O7.　The　results　suggested　that　phosphate　is　removed　by　ZVI　mainly　through　precipitation　under　aerobic　conditions.　The　knowledge　gained　in　this　study　improves　the　fundamental　understanding　of　the　phosphate　removal　processes　via　ZVI.　©　2023