A　novel,　bifunctional　mesoporous　silica　(Al-SBA-15-G)　capable　of　the　simultaneous　removal　of　cations　and　anions　from　wastewater　was　synthesized　by　the　incorporation　of　aluminum　into　the　framework　of　SBA-15　followed　by　the　immobilization　of　melamine-based　dendrimer　groups　onto　the　surface　of　the　Al-substituted　SBA-15.　This　material　was　characterized　by　XRD,　SEM,　TEM,　NH3-TPD,　FTIR,　and　N2　adsorption/desorption.　The　bifunctional　Al-SBA-15-G　contains　a　large　amount　of　aluminum　hydroxyl　groups　and　amine　groups,　which　were　considered　to　be　responsible　for　the　formation　of　cation　and　anion　complexes,　respectively.　Due　to　the　steric　effects　of　the　melamine-based　dendrimer　groups,　the　aluminum　hydroxyl　and　amine　groups　on　Al-SBA-15-G　keep　an　appropriate　distance　with　a　cooperative　manner　and　avoid　spontaneous　neutralization　reactions.　The　maximum　adsorption　capacities　toward　Cu2+　and　SO42-　of　Al-SBA-15-G　were　0.763　mmol/g　and　0.511　mmol/g,　respectively.　A　mechanism　for　the　simultaneous　adsorption　of　cations　and　anions　by　Al-SBA-15-G　is　proposed.　As　a　bifunctional　adsorbent,　Al-SBA-15-G　can　potentially　be　used　for　the　simultaneous　removal　of　cations　and　anions　from　wastewater.　©　2015　Elsevier　B.V.　All　rights　reserved.