The treatment of simulated cationic red GTL dye wastewater was conducted by coupling technology of catalytic wet air oxidation(CWAO)with membrane filtration

using Mo-Zn-Al-O as catalyst.The filtration mechanism of polyvinylidene fluoride hollow fiber microfiltration(MF)membranes with average pore size 0.1 μm and ultrafiltration(UF)membranes with average pore size 0.022 μm was investigated.It was found that the degradation efficiency of hybrid system was superior to CWAO with single process.Under 0.01 MPa pressure for 120 min the fluxes of MF and UF declined 26.63% and 16.48%

respectively.The reason for flux decline of microfiltration membrane was considered to be the blocking of pores and the formation of cake layer on the membrane surface by deposited catalyst powder

while that of ultrafiltration was dominated by cake layer formation.The experimental results showed that the irreversible resistance in microfiltration was larger than that in ultrafiltration after the same process.Under different operation conditions

a linear relationship could be obtained between the filtration resistance and specific deposit.