ObjectiveAs a pretreatment unit in seawater desalination, ultrafiltration (UF) serves as a critical barrier to ensure the stable operation of the core desalination reverse osmosis membrane. However, under low winter temperatures in northern China, traditional organic UF membranes face significant challenges, including reduced water production capacity and increased membrane filament breakage rates. To address these issues, this study conductes pilot-scale demonstrations of low-temperature seawater desalination pretreatment using domestically developed inorganic ceramic UF membranes, which exhibit high mechanical strength and thermal stability.MethoodsUnder both ambient (from 16.7 to 20.9 ℃) and low-temperature (from 2.2 ℃ to 5.0 ℃) conditions, constant-pressure and constant-flow operational modes were employed to evaluate and compare the permeate flux, transmembrane pressure difference (TMP), and water production variations of ceramic and organic membranes.ResultsUnder constant-pressure operation, ceramic membranes demonstrated significantly higher permeate flux than organic membranes at ambient temperatures. Although the permeate flux of ceramic membranes declined more markedly than that of organic membranes under low-temperature conditions, they still outperformed organic membranes. Under constant-flow operational mode, ceramic membranes could enhance filtration driving force by increasing the TMP, thereby maintaining stable water production. In contrast, low-temperature conditions exerted a more pronounced adverse effect on organic membranes, with their water yield dropping to merely from 37% to 41% of that observed under ambient temperatures.ConclusionThe domestically developed ceramic membranes exhibit superior water production stability compared to organic membranes in low-temperature pilot-scale trials. These findings provide technical references and operational parameter guidelines for the practical application of ceramic membranes in low-temperature seawater desalination pretreatment processes.