Ca/Fe-rich　antibiotic　fermentation　residues　(AFRs),　a　type　of　hazardous　waste,　can　be　regarded　as　recyclable　biomass　and　metal　resources.　However,　concurrent　detoxification　and　reutilization　of　biomass　and　metals　resources　from　AFRs　have　never　been　reported　before.　In　this　study,　Ca/Fe-rich　vancomycin　fermentation　residues　were　pyrolyzed　into　biochar　to　adsorb　phosphate　for　the　first　time.　The　residual　vancomycin　and　antibiotic　resistance　genes　were　completely　decomposed　during　pyrolysis.　The　resultant　Ca/Fe-rich　biochar　exhibited　excellent　performance　at　adsorbing　phosphate　without　further　modifications.　The　process　had　rapid　kinetics　and　a　maximum　adsorption　capacity　of　102　mg　P/g.　Ca　and　Fe　were　the　active　sites,　whereas　different　mechanisms　were　observed　under　acidic　and　alkaline　conditions.　Surprisingly,　HCO3−　enhanced　phosphate　adsorption　with　an　increase　of　adsorption　capacity　from　43.9　to　71.0　mg/g　when　HCO3−　concentration　increased　from　1　to　10　mM.　Furthermore,　actual　wastewater　could　be　effectively　treated　by　the　biochar.　The　phosphate-rich　spent　biochar　significantly　promoted　seed　germination　(germination　rate:　96.7　%　vs.　80.0　%　in　control　group,　p　©　2023