The　aim　of　this　study　was　to　determine　the　feasibility　of　the　use　of　inactive　aerobic　granules　as　a　biosorbent　for　removing　Acid　Red　14　(AR　14),　an　anionic　azo　dye,　from　aqueous　solution.　The　effects　of　pH,　biosorbent　dosage,　initial　AR　14　concentration,　NaCl　concentration　and　temperature　on　the　biosorption　were　investigated.　The　results　show　that　initial　pH　would　be　the　most　important　parameter　affecting　AR　14　biosorption　and　the　optimal　pH　was　2.0.　The　biosorption　capacity　increased　with　an　increase　in　initial　dye　concentration,　but　decreased　with　an　increase　in　biosorbent　dosage　and　NaCl　concentration.　The　Langmuir　and　Redlich-Peterson　isotherms　fitted　better　to　the　equilibrium　data　than　the　Freundlich　isotherm.　Pseudo-first-order,　pseudo-second-order　and　intraparticle　diffusion　models　were　applied　to　fit　the　experimental　data,　and　the　results　show　that　the　biosorption　of　AR　14　followed　the　pseudo-second-order　kinetic　model.　The　thermodynamic　analysis　indicates　that　the　biosorption　process　was　endothermic　in　nature　and　could　occur　spontaneously.　The　FTIR　analysis　revealed　that　chemical　functional　groups　(e.g.,　amine,　carboxyl,　hydroxyl　and　either)　on　aerobic　granules　would　be　the　active　binding　sites　for　biosorption　of　AR　14.　These　results　show　that　inactive　aerobic　granules　could　be　employed　as　a　low-cost　and　alternative　biosorbent　in　the　wastewater　treatment　for　the　removal　of　anionic　azo　dye　AR　14.