The　increasing　number　of　bacteria-related　problems　and　presence　of　trace　amounts　of　phosphate　in　treated　wastewater　effluents　have　become　a　growing　concern　in　environmental　research.　The　use　of　antibacterial　agents　and　phosphate　adsorbents　for　the　treatment　of　wastewater　effluents　is　of　great　importance.　In　this　study,　the　potential　applications　of　a　synthesized　polyaniline　(PANI)–zirconium　dioxide　(ZrO2)　composite　as　an　antibacterial,　phosphate　adsorbent　and　anti-corrosion　material　were　systematically　investigated.　The　results　of　an　antibacterial　test　reveal　an　effective　area　of　inhibition　of　14　and　18　mm　for　the　Escherichia　coli　and　Staphylococcus　aureus　bacterial　strains,　respectively.　The　antibacterial　efficiency　of　the　PANI–ZrO2　composite　is　twice　that　of　commercial　ZrO2.　In　particular,　the　introduction　of　PANI　increased　the　specific　surface　area　and　roughness　of　the　composite　material,　which　was　beneficial　to　increase　the　contact　area　with　bacterial　and　phosphate.　The　experimental　results　demonstrated　that　phosphate　adsorption　studies　using　200　mg　P/L　phosphate　solution　showed　a　significant　phosphate　removal　efficiency　of　64.4%,　and　the　maximum　adsorption　capacity　of　phosphate　on　the　solid　surface　of　PANI–ZrO2　is　32.4　mg　P/g.　Furthermore,　PANI–ZrO2　coated　on　iron　substrate　was　tested　for　anti-corrosion　studies　by　a　natural　salt　spray　test　(7.5%　NaCl),　which　resulted　in　the　formation　of　no　rust.　To　the　best　of　our　knowledge,　no　works　have　been　reported　on　the　synergistic　effects　of　the　PANI–ZrO2　composite　as　an　antibacterial,　anti-corrosion,　and　phosphate　adsorbent　material.　PANI–ZrO2　composite　is　expected　to　be　a　promising　comprehensive　treatment　method　for　water　filters　in　the　aquaculture　industry　and　for　use　in　water　purification　applications.　©　2017,　©　2017　Informa　UK　Limited,　trading　as　Taylor　&　Francis　Group.