Microcystin　cyanobacterial　hepatotoxins　represent　an　increasingly　severe　global　health　hazard.　This　study　focused　on　enhancing　photocatalytic　degradation　of　microcystin-LR　(MCLR)　following　the　addition　of　ferrate　as　the　indirect　electron　acceptors　to　the　process.　The　degradation　rate　of　MCLR　by　ferrate　or　the　photocatalysis　only　was　54　and　63%,　respectively.　However,　when　relatively　low　ferrate　dose　(0.08　mmol/L)　was　added　to　the　photocatalytic　process,　a　significant　enhancement　in　the　photocatalytic　rate　was　observed　and　the　efficiency　can　be　increased　to　100%.　Compared　the　effect　of　Fe(III)　and　Fe(VI)　on　the　photocatalysis　rate,　the　process　of　Fe(VI)-assisted　photocatalytic　degradation　of　MCLR　apparently　existed　the　synergistic　effect　and　the　photocatalysis　rate　constant　k　of　Fe(VI)/UV/TiO2　process　was　higher　than　Fe(III)/　UV/TiO2　by　2.5　times　and　than　UV/TiO2　by　4.4　times,　but　an　overdose　of　ferrate　will　retard　the　rate　due　to　the　short　circuiting　reactions　between　Fe3+　and　Fe2+　and　the　lower　absorption　of　UV　light.　As　expected,　pH　had　a　remarkable　influence　on　the　reaction　rate　of　detoxification　of　microcystin-LR　and　pH　6　was　beneficial　to　the　photocatalytic　process.　©　2005　Elsevier　B.V.　All　rights　reserved.