Recently,　layered　double　hydroxides　(LDH)　have　been　proven　to　be　promising　adsorbents　in　the　field　of　wastewater　treatment　mainly　due　to　their　unique　characteristics.　In　this　study,　a　series　of　MgxAl-LDH　(x　is　the　molar　ratio　of　Mg/Al)　were　synthesized　via　a　supersaturated　co-precipitation　method　and　used　for　the　removal　of　low　concentration　nitrate　(NO3-).　Based　on　the　results,　Mg5Al-LDH　showed　a　significantly　enhanced　adsorption　capacity　of　9.76　mg　g-1,　and　the　removal　efficiency　of　NO3-　(C0　=　1　mg　L-1)　reached　about　80%　after　6　h　at　25　°C　and　neutral　pH.　As　proved　by　various　characterization　studies,　changes　in　the　molar　ratio　of　Mg/Al　would　influence　the　surface　active　groups　and　layer　distance　of　the　synthesized　LDH,　thereby　affecting　the　adsorption　of　NO3-.　In　addition,　the　synthesized　LDH　presented　a　mesoporous　structure,　which　can　reduce　the　obstruction　for　adsorbing　NO3-.　Studies　on　the　reaction　kinetics　indicated　that　the　NO3-　adsorption　behavior　of　Mg5Al-LDH　can　be　well　fitted　by　the　pseudo-second-order　kinetic　and　Langmuir　models,　demonstrating　that　the　resultant　adsorption　is　a　spontaneous,　exothermic　and　entropy　decreasing　process　with　physical　and　chemical　effects　simultaneously.　By　further　clarifying　the　mechanisms　of　NO3-　removal,　the　synthesized　Mg5Al-LDH　could　be　thought　of　as　an　efficient,　environmentally　friendly,　and　low-cost　adsorbent　to　remove　NO3-　from　the　aquatic　environment.　©　The　Royal　Society　of　Chemistry　and　the　Centre　National　de　la　Recherche　Scientifique.