This　study　investigates　the　behavior　and　fate　of　TiO2　NPs　in　conventional　water　treatment　(coagulation/flocculation/sedimentation)　under　the　influence　of　waterborne　phosphate,　focusing　on　the　phosphate　uptake　rate,　surface　interactions,　and　dispersion　stability　and　removal　efficiency　of　TiO2　NPs.　The　adsorption　of　HPO42-　ions　on　TiO2　NPs　(i.e.,　surface　complexation　in　solution)　causes　displacement　of　carbonate　species.　Moreover,　adsorption　experiments　indicates　that　complexation　of　inorganic　anions　on　the　surfaces　of　TiO2　NPs　can　occur　rapidly,　within　a　5　min　time　frame.　This　study　confirmed　that　phosphate　would　affect　the　surface　charge　of　the　TiO2　NPs;　thus,　the　bridging　effect　during　coagulation　may　also　be　hindered　by　phosphate　becoming　attached　to　TiO2　NP　surfaces.　This　information　will　contribute　to　nanotechnology-related　water　safety　and　water　treatment　technology.　(C)　2019　Elsevier　Ltd.　All　rights　reserved.