Permeate flux recovery of ceramic membrane using TiO2 with catalytic ozonation

In the present study, ozonation and catalytic ozonation were applied in ceramic membrane ultrafiltration to investigate their effects on membrane fouling. The humic acid solution and titanium dioxide (TiO2) were used as tested water and catalyst, respectively. Controlled operating parameters include ozone gas flow rate, catalyst dosage and ozone dosage. The results reveal that the permeate flux of membrane could be recovered up to 98% of the initial permeate flux when ozone gas was injected into the membrane module at the time of permeate flux decreased to 60% of the initial permeate flux. Two monitored water quality parameters, dissolved organic carbon (DOC) and UV absorbance at 254 nm (UV254) were both removed up to 97% under tested experimental conditions. When TiO2 was used as the catalyst in catalytic ozonation, the permeate flux of membrane was only recovered up to 93% of the initial permeate flux when catalysts and ozone gas were introduced into the membrane module at the time of permeate flux decreased to 60% of the initial permeate flux. However, the decrease of DOC and UV254 achieved up to 97% and 100%, respectively. This indicates that the application of catalytic ozonation in the ceramic membrane ultrafiltration system could obtain higher permeate water quality than using ozonation alone. Both ozonation and catalytic ozonation could effectively reduce membrane fouling and maintain stable permeate flux of the tested ceramic membrane system.