Abstract:Two combination processes, including ozonation-ceramic membrane-biological activated carbon (BAC) (processⅠ) and ceramic membrane-BAC (processⅡ), were tested to treat polluted raw water. The performance was evaluated with the removal efficiencies of turbidity, ammonium and organic matters in a scale of 3L/d.The effects of ozone on membrane flux and BAC were also considered. More than 96% of turbidity was removed by both combination processes either with or without ozone addition. The ammonium that can be removed by both processes was limited to 1.0~2.0mg/L. Increasing the dissolved oxygen to 30.0mg/L can lead to a complete removal of ammonium with the concentration as high as 5.5mg/L. The average removal efficiencies of the total organic carbon (TOC) and ultraviolet absorbance at 254nm were 48.3% and 51.8% for processⅠwithout ozone addition, 51.1% and 48.2% for processⅡwhen ozone dosage was 2.0mg/L. Ozonation had no effect on turbidity removal, while it resulted in the changes of organic molecular structure at an ozone dosage of 2.0mg/L and this helped alleviate the membrane fouling. Membrane flux in processⅠincreased by 25%~30% compared with that in processⅡ with no ozone addition. However, residual ozone may affect the microbial activities in the BAC, which impacted the removals of organic matter and ammonia negatively.