Based　on　the　concept　of　waste　control　by　waste,　agroforestry　waste　oil-tea　cake　was　used　to　remove　azo　dye　Reactive　Red　15　(RR15)　via　biosorption　from　aqueous　solution.　To　optimize　the　biosorption　condition,　a　Box-Behnken　Design　with　a　response　surface　methodology　was　carried　out.　Three　independent　variables-pH,　initial　RR15　concentration　and　biosorption　temperature-were　studied,　and　biosorption　capacity　and　removal　efficiency　were　set　as　the　response　values.　Statistical　analysis　showed　that　pH　was　highly　significant　for　both　biosorption　capacity　and　removal　efficiency　(P0gained　from　Langmuir　isotherm　model　at　20　was　74.63　mg/g.　The　kinetic　study　showed　that　the　experimental　data　were　well　fitted　by　the　pseudo-second-order　model　(R2＞0.9997),　which　indicated　that　the　dominant　biosorption　belonged　to　the　chemisorptive　nature.　Both　intra-particle　diffusion　and　boundary　layer　diffusion　might　affect　the　biosorption　rate.　Thermodynamic　study　demonstrated　that　the　biosorption　was　a　spontaneous　and　exothermic　process.　To　understand　the　mechanical　behavior　of　RR15　biosorption　process,　SEM,　EDS　and　FTIR　were　employed　to　characterize　the　oil-tea　cake　pre-and　post-biosorption.　The　FTIR　analysis　indicated　that　functional　groups　(e.g.,　amine,　hydroxyl)　on　the　oil-tea　cake　biosorbent　were　the　active　binding　sites　for　the　RR15　biosorption.　These　results　showed　that　oil-tea　cake　is　a　promising　biosorbent,　which　could　effectively　remove　RR15　from　dye　wastewater.　©　2015,　Editorial　Department　of　Molecular　Catalysis.　All　right　reserved.