The　activated　carbon　from　sewage　sludge　was　modified　with　sulphuric　acid.　The　influence　of　modification　time　and　the　concentration　of　sulphuric　acid　on　adsorption　capacity　were　investigated　in　the　test.　In　the　best　condition　of　modified,　the　effects　of　various　experimental　parameters　such　as　agitation　time,　initial　ion　concentration　and　pH　were　also　studied.　The　isothermal　adsorption　characteristics　and　kinetic　dynamics　models　of　original　and　modified　sludge　activated　carbon　adsorbing　Cr6+　were　used　to　analyze　the　dynamic　process.　Results　show　that　the　sludge　activated　carbon　modified　2　hours　with　1:　5　concentration　of　the　sulphuric　acid　has　the　best　adsorption　capacity,　which　reaches　9.44　mg/g,　increased　by　53%　compared　with　the　original　sludge　activated　carbon.　Adsorption　data　agrees　well　with　the　Langmuir　and　pseudo-second　order　kinetic　model.