The surface morphology and hydrophilicity of the UF membrane wire during different operation phases

as well as the contamination on it were investigated.Results indicate that

the main pollutants are colloidal silica

colloidal iron and colloidal aluminum

which can easily form fouling layers on surface of the UF membrane.In earlier stage

the contamination mainly composes of massive and loose matters.As the running time increasing

the fouling layers gradually transform into dense gel layers.At this moment

compared to clean membrane wire

the contaminated one has larger contact angle

lower hydrophilicity and higher fouling speed.Therefore

the authors suggest strengthening physical cleaning during the earlier stage of contamination formation

and decreasing the amount of additions such as ferric salt and aluminum salt as low as possible

on the premise of ensuring the effluent of coagulation and clarification system is qualified.