Calcium　(Ca)/Iron　(Fe)-rich　antibiotic　fermentation　residue　(AFR)　is　a　hazardous　waste　in　China　and　is　also　biomass　and　metal　resources.　However,　a　few　studies　have　focused　on　the　concurrent　recycle　of　the　two　resources.　Meanwhile,　information　about　the　application　of　AFR-derived　biochars　is　still　limited.　In　this　study,　the　Ca/Fe-rich　tobramycin　fermentation　residue　was　used　for　the　preparation　of　hydrochars　and　pyrochars　by　hydrothermal　and　pyrolysis　methods,　respectively,　and　the　adsorption　performance　and　mechanism　of　the　hydrochars　and　pyrochars　for　phosphate　were　also　investigated.　The　results　show　that　both　hydrochars　and　pyrochars　contained　high　content　of　Ca　and　Fe.　The　pyrochars　exhibited　higher　affinity　for　phosphate　and　stronger　magnetism　without　further　modifications　than　the　hydrochars.　Among　the　pyrochars,　the　one　prepared　at　600　°C　(denoted　as　PC-600)　had　the　highest　adsorption　capacity　(45.5　mg/g)　for　phosphate,　and　it　was　selected　for　the　batch　adsorption　experiments.　In　the　pH-dependent　experiments,　it　is　found　that　PC-600　exhibited　better　adsorption　performance　for　phosphate　under　the　alkaline　conditions.　When　there　were　anions　in　the　solution,　the　adsorption　capacity　of　PC-600　was　almost　not　affected　by　Cl−　and　NO3−　and　was　inhabited　by　SO42−　and　CO32−.　Interestingly,　HCO3−　itself　showed　little　effect　on　the　adsorption　of　phosphate　and　increased　the　solution　pH.　Therefore,　the　apparent　adsorption　capacity　of　PC-600　for　phosphate　was　significantly　promoted　by　the　presence　of　HCO3−　(P＜0.05).　Furthermore,　PC-600　exhibited　rapid　kinetics　with　an　equilibrium　time　of　420　min.　The　isotherm　data　could　be　fitted　well　by　the　Langmuir　model,　and　the　maximum　adsorption　capacity　(qm)　reached　108　mg/g　at　35　°C.　Characterizations　revealed　that　the　main　adsorption　mechanisms　included　precipitation　and　ligand　exchange.　The　results　showed　pyrolysis　is　a　promising　method　to　treat　Ca/Fe-rich　AFR,　and　the　obtained　Ca/Fe-rich　pyrochars　can　be　used　as　adsorbents　for　phosphate　removal　or　recovery　from　wastewater.　In　summary,　this　study　provides　new　insights　for　the　concurrent　recovery　and　utilization　of　both　biomass　and　metal　resources　from　the　Ca/Fe-rich　AFR　and　for　the　application　of　the　AFR-derived　biochars.　©　2023　Editorial　Board,　Research　of　Environmental　Sciences.　All　rights　reserved.