Study on three-step cleaning of ceramic membrane and analysis of its effects

Ultrafiltration membrane was used to treat oilfield produced water.According to the analysis of the composition of inorganic scales on ceramic membrane and basket strainer and the SEM photos of the ceramic membrane′s cross section,the variation of parameters such as: reagent and ion concentration,transmembrane pressure and so on during the course of cermic membrane cleaning were studied;meanwhile,the variation of transmembrane pressure and water production during the membrane operation were also investigated.The alkali-complexing agent-oxidizer three-step washing was finally determined to be the proper process for fouled ZrO2 ceramic membrane cleaning at a temperature of 40 ℃.The results of the pilot scale test showed that,after the cleaning,the recovery rates of membrane flux at high and low pressure terminals were 97.1% and 116.8% respectively,the maximum operation time reached 68 h.The said process had a good repeatability,moreover,the advantages of it on aspects of cost control,operating condition,cleaning effect and so on were also obvious.