Photocatalytic　oxidation　using　UV　irradiation　of　TiO2　has　been　studied　extensively　and　has　many　potential　industrial　applications,　including　the　degradation　of　recalcitrant　contaminants　in　water　and　wastewater　treatment.　A　limiting　factor　in　the　oxidation　process　is　the　recombination　of　conduction　band　electrons　(e　(-)　(cb))　with　electron　holes　(h　(vb)　(+)　)　on　the　irradiated　TiO2　surface;　thus,　in　aqueous　conditions,　the　presence　of　an　effective　electron　scavenger　will　be　beneficial　to　the　efficiency　of　the　oxidation　process.　Ferrate　(FeO　(4)　(2-)　)　has　received　much　recent　attention　as　a　water　treatment　chemical　since　it　behaves　simultaneously　as　an　oxidant　and　coagulant.　The　combination　of　ferrate　[Fe(VI)]　with　UV/TiO2　photocatalysis　offers　an　oxidation　synergism　arising　from　the　Fe(VI)　scavenging　of　e　(-)　(cb)　and　the　corresponding　beneficial　formation　of　Fe(V)　from　the　Fe(VI)　reduction.　This　paper　reviews　recent　studies　concerning　the　photocatalytic　oxidation　of　problematic　pollutants　with　and　without　ferrate.　The　paper　reviews　the　published　results　of　laboratory　experiments　designed　to　follow　the　photocatalytic　degradation　of　selected　contaminants　of　environmental　significance　and　the　influence　of　the　experimental　conditions　(e.g.　pH,　reactant　concentrations　and　dissolved　oxygen).　The　specific　compounds　are　as　follows:　ammonia,　cyanate,　formic　acid,　bisphenol-A,　dibutyl-　and　dimethyl-phthalate　and　microcystin-LR.　The　principal　focus　in　these　studies　has　been　on　the　rates　of　reaction　rather　than　on　reaction　pathways　and　products.　The　presence　of　UV/TiO2　accelerates　the　chemical　reduction　of　ferrate,　and　the　reduction　rate　decreases　with　pH　owing　to　deprotonation　of　ferrate　ion.　For　all　the　selected　contaminant　substances,　the　photocatalytic　oxidation　rate　was　greater　in　the　presence　of　ferrate,　and　this　was　believed　to　be　synergistic　rather　than　additive.　The　presence　of　dissolved　oxygen　in　solution　reduced　the　degradation　rate　of　dimethyl　phthalate　in　the　ferrate/photocatalysis　system.　In　the　study　of　microcystin-LR,　it　was　evident　that　an　optimal　ferrate　concentration　exists,　whereby　higher　Fe(VI)　concentrations　above　the　optimum　leads　to　a　reduction　in　microcystin-LR　degradation.　In　addition,　the　rate　of　microcystin-LR　degradation　was　found　to　be　strongly　dependent　on　pH　and　was　greatest　at　pH　6.　The　initial　rate　of　photocatalytic　reduction　under　different　conditions　was　analysed　using　a　Langmuirian　form.　Decrease　in　rates　in　the　presence　of　dissolved　oxygen　may　be　due　to　competition　between　oxygen　and　ferrate　as　electron　scavengers　and　to　non-productive　radical　species　interactions.　The　reaction　between　ferrate(VI)　and　microcystins-LR　in　the　pH　range　of　6.0-10.0　is　most　likely　controlled　by　the　protonated　Fe(VI)　species,　HFeO　(4)　(-)　.　The　photocatalytic　oxidation　of　selected,　recalcitrant　contaminants　was　found　to　be　significantly　greater　in　the　presence　of　ferrate,　arising　from　the　role　of　ferrate　in　inhibiting　the　h　(vb)　(+)　-e　(-)　(cb)　pair　recombination　on　TiO2　surfaces　and　the　corresponding　generation　of　highly　oxidative　Fe(V)　species.　The　performance　of　the　ferrate/photocatalysis　system　is　strongly　influenced　by　the　reaction　conditions,　particularly　the　pH　and　dissolved　oxygen　concentration,　arising　from　the　complex　nature　of　the　interactions　between　the　catalyst　and　the　solution.　Overall,　the　treatment　performance　of　the　Fe(VI)-TiO2-UV　system　is　generally　superior　to　alternative　chemical　oxidation　methods.　The　formation　of　intermediate　Fe(V)　species　in　the　photocatalytic　reduction　of　ferrate(VI)　requires　confirmation,　and　a　method　involving　electron　paramagnetic　resonance　spectroscopy　could　be　applied　for　this.　The　reactivity　of　Fe(V)　with　the　selected　contaminants　is　required　in　order　to　better　understand　the　role　of　ferrate　in　the　Fe(VI)-TiO2-UV　oxidation　system.　To　increase　the　practical　utility　of　the　system,　it　is　recommended　that　future　studies　involving　the　photocatalytic　oxidation　of　pollutants　in　the　presence　of　ferrate(VI)　should　focus　on　developing　modified　TiO2　surfaces　that　are　photocatalytic　under　visible　light　conditions.