the influence of temperature on dynamic membrane structure
abstract
this study investigates the influences of cold source-water temperatures and warm
temperature recoveries on the dynamic changes of membrane structure. the morphology of
membrane pores on the membrane surface was firstly compared through sem images. the visual
comparisons of the images show that the shrinkage of membrane pores occurred in the cold-water
(0.3, 5, 10°c) treatments and could then be recovered in the warm-water (room temperature and
35°c) remediation. furthermore, the dynamic changes in membrane pore sizes during cold
temperature and recovery treatments were illustrated by the percentile membrane diameters —
d10, d50 and d90. the membrane pore sizes in cold-water treatment at 0.3°c shrank faster and
were smaller than those of 5 and 10°c. the recovery treatment at 35°c, which fully recovered the
membrane pore sizes to those of virgin membrane, was much more effective than room
temperature treatment. room temperature recovery only restored the membrane pores close but
not exceeding the original sizes under tested conditions. both cold temperature treatments and
warm water recoveries stabilized the membrane pore sizes after around 24 hours. finally,
membrane structure changes over time have been modelled. it implied that warm water cleaning
could retrieve the membrane structure losses affected by cold source water.