Effect of cold water temperature on membrane structure and properties

The temperature dependence of intrinsic hollow fiber (HF) membrane structure and properties (lumen dimension, pore size distribution, porosity, permeability, resistance, dextran rejection, and break strength) were investigated at room temperature of 21 +/- 1 degrees C and extreme cold water temperature of 0.3 degrees C in a well-controlled cold room. No significant changes in membrane structures and properties were observed in three months continuous filtration operation at room temperature (21 +/- 1 degrees C). A decrease in membrane lumen diameter and membrane permeability and an increase in the intrinsic hydraulic resistance and dextran rejection were observed for membrane operated at the extreme cold water temperature (0.3 degrees C) in the first few weeks of operation. An increase in operational membrane flux resulted in a more significant changes in membrane structure and properties at 0.3 degrees C. The results suggest that extreme cold water temperature could alter the intrinsic membrane structure and properties in the first few weeks of operation, the changes in membrane structure were largely reversible under tested conditions, although a significant change (11% increase in resistance) remained. A reduction in operational membrane flux in the cold season could minimize changes in membrane structure and properties.