The　oxidative　degradation　of　chlorinated　ethylenes　with　a　metal-oxo　reagent,　potassium　ferrate　(K2FeO4),　is　investigated　in　this　paper.　The　encapsulated　K2FeO4　was　prepared　by　a　molten　suspension　and　cooling　method,　with　paraffin　wax　and　K2FeO4　solid　as　the　encapsulating　wall　and　encapsulated　core,　respectively.　The　effects　of　three　main　factors,　stirring　time,　ultrasonic　time　and　temperature　of　the　water　bath,　on　the　preparation　of　encapsulated　ferrate　were　studied.　The　IR　and　XRD　spectra　showed　that　ferrate　was　stable　after　encapsulation.　Experiments　also　showed　that　the　release　process　of　K2FeO4　from　the　encapsulated　particles　includes　two　phases:　(1)　the　uncoated　ferrate　was　immediately　dissolved　(＜lmin);　(2)　the　encapsulated　ferrate　was　sustained　to　release　in　108　h.　The　release　kinetics　were　in　good　agreement　with　the　Q　=　ktn　model.　A　well-defined　change　in　the　surface　morphology　before　and　after　release　reaction　was　observed　by　SEM.　A　higher　amount　of　stable　ferrate　was　recovered　from　the　encapsulated　paraffin　when　compared　to　pure　ferrate　itself.　A　primary　research　showed　that　trichloroethylene　(TCE)　degradation　could　be　more　effective　in　acidic　medium　since　above　90%　of　the　TCE　was　degraded　after　a　reaction　time　of　60　mins　in　solutions　with　pH　=　4.0　-　6.0,　compared　to　only　60%　TCE　degradation　after　150　mins　in　solutions　with　pH　=　10.　©　2008　American　Chemical　Society.