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The effect of mixed liquor properties changed by ozonation especially with high dosages on membrane fouling is very complex and remains unclear. In this study, the effect of mixed liquor properties changed by ozonation especially with high dosages on ceramic ultrafiltration (UF) membrane fouling in wastewater treatment and the corresponding mechanism were systematically studied by characterization of the mixed liquor properties, hydraulic performance, the fouling layers and modeling at different ozone dosages (0, 2, 5, 10 mg/L). The membrane filterability of the mixed liquor after pre-ozonation (⩽5 mg/L) was enhanced and the corresponding membrane fouling was mitigated. After pre-ozonation, activated sludge had the better settleability and larger floc size. Meanwhile, there was a remarkable reduction of dissolved organic carbon (DOC), soluble microbial products (SMP) and extractable extra-cellular polymeric substances (EPS) after pre-ozonation and the removed organics were mainly belonged to the high molecular weight (MW) (1–10 kDa) and very high MW (10–200 kDa) substances. Intermediate blocking was the main membrane fouling during the mixed liquor filtration process and the best fouling mitigation performance was achieved for the sample with an intermediate ozone dosage of 5 mg/L (1.7 mg-ozone/g-mixed liquor suspended solids (MLSS)). Meanwhile, the water quality of permeate was even better after pre-ozonation (⩽5 mg/L) with the lower DOC and total nitrogen (TN) concentrations. Severe cell lysis occurred with the significant increase of the released organics in the mixed liquor and the activated sludge had smaller floc size and worse settleability when the pre-ozonation dosage was above 10 mg/L, which in turn resulted in the deteriorated membrane fouling control performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ceramic membrane (CM) market is growing with many full-scale applications. • CM is superior to polymeric membrane–high stability & flux, long life, low fouling. • Physicochemical processes (e.g., ozonation) are effective for fouling control. • Catalytic (nano) CMs can enhance antifouling, and pollutant removal capability. • Cost analysis of CMs, fouling control & cleaning should be evaluated at full-scale. Application of ceramic membrane technology in water and wastewater is rapidly growing. Inherent advantages of ceramic membrane including chemical/thermal stability, low fouling propensity and long lifespan make ceramic membrane technology attractive, and the ceramic membrane market is expected to achieve a compound annual growth rate of 12%. Ceramic membranes could be integrated with advanced oxidation processes such as in-situ ozonation that cannot be applied in the case of polymeric membrane due to their potential degradation during long-term exposure. In addition, the hybrid-ceramic membrane processes such as ceramic membrane bioreactor are superior to polymeric counterparts due to higher flux, higher pollutant removal, lower fouling rate and higher cleaning efficiency. Although ceramic membrane has high capital cost, life-cycle costs of ceramic and polymeric plants are comparable. Notably, full-scale ceramic membrane water/wastewater treatment plants have been installed in many countries such as Japan, USA, Singapore and United Kingdom. Given the attractiveness of this technology, performance of ceramic membrane is critically reviewed with a focus on their applications in water and wastewater treatment under mild conditions. In addition, fouling mechanisms and control strategies are elucidated and are compared with polymeric membranes. Importantly, for the first time, the status of full-scale applications and market prospects of ceramic membranes are critically analysed to show their future potential. Lastly, future research directions such as development of cost-effective ceramic membranes, understanding the biofouling evolution and economic evaluation of physicochemical processes for fouling control are proposed. [ABSTRACT FROM AUTHOR]