الفهرس 
Chapter II Review of LiteratureOnly 14 pages are availabe for public view
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Abstract
-All factors which could effect on preparation of PSf membrane by wet
phase inversion were studied by evaluation under VEDCMD unit and
experimental results illustrated that DMF was suitable solvent than
DMAc to synthetize membranes of MD from PSf, increase in
concentration of PSf in casting solution inversely proportion with
MD Flux, 15 % w/v was the best concentration, increase in thickness
of PSf membrane led to reduction in MD flux, increase in solvent
evaporation time before coagulation step decline MD flux, temperature
of coagulation increase led to decrease of MD flux,(25 oC) was
selected as best coagulation temperature and presence different
concentration of solvent in coagulation bath effect slightly on MD flux
also presence of LiCl with different concentration in coagulation bath
led to enhancement of MD flux.
2-Operation parameters which could effect on MD flux were studied by
using membrane of PSf (15% w/v) where experimental results
illustrated the increase of feed temperature increase flux of MD, on
contrary increase of permeate temperature decrease MD flux this
according to thermodynamic effect, also increase in feed flow rate
increase MD flux as reducing of temperature polarization with fast
flow rate, increase in feed concentration decrease slightly MD flux so
MD suitable desalination process for high water salinity, also decrease
of pores pressure in permeate side by vacuum enhance MD flux and
this pressure must be less than membrane LEP. Durability of
membrane was investigated as function with MD flux and permeate
EC where PSf membrane gave good stability and salt reject through
operation time period ,it is found that change of feed salt type effect on
MD flux according to Rout’s law as we found MD flux of NaCl >
MgSO4 >Na2SO4 at same operation conditions.
3-All modified PSf membrane with different nano-materials and different
concentrations were studied where PSf/MWCNTs membranes MD
Conclusion and recommendations
[135]
flux increase with MWCNTs increase until (1%) then flux started in
reduction and this was attributed to tubular nature of MWCNTs , its
hydrophobicity , its effect on morphology of PSf membrane and all
this effect on mass transfer mechanism of PSf membrane .Also we
found that (0.5%) was the best concentration was added to PSf/SiO2
membrane when we used silica mesoporous with different
concentration and (0.75%) was optimal TiO2 concentration was added
to PSf/TiO2 also (0.5 %) was the best ZnO concentration could give
high MD flux all this inorganic nonmaterial effect by significantly on
PSf membrane morphology as illustrated in SEM images and other
characterization analysis. Dispersion sonication time of different nanomaterials
was studied as function with MD flux where sonication time
of MWCNTs in dispersion medium of DMF had clear effect on MD
flux productivity also in case of TiO2 and ZnO sonication increasing
enhanced MD flux of PSf. Moreover, comparison study was done
between neat PSf membrane and optimal modified membranes.