In　this　work,　a　new　ultrasound-assisted　heterogeneous　activation　of　persulfate　by　nano　zero-valent　iron　(USnZVI/PS)　technique　was　employed　to　regenerate　powder　activated　carbon　(PAC)　that　had　been　saturated　with　chloramphenicol　(CAP).　US-nZVI/PS　process　can　successfully　regenerate　the　CAP-saturated　PAC.　Response　surface　methodology　was　effectively　performed　and　under　the　specific　optimum　regeneration　conditions　the　actual　experimental　regeneration　efficiency　of　PAC　reached　93.96%.　As　evidenced　by　the　results　of　EPR　and　quenching　experiments,　both　SO4　center　dot-　and　center　dot　OH　were　identified　as　the　main　reactive　species　responsible　for　the　regeneration　process.　The　regeneration　process　considerably　promoted　the　generation　of　oxygen-derived　surface　functional　groups.