چكيده به لاتين
Abstract:
Membrane filtration technologies with different types of membranes show great promise for
heavy metal removal for their high efficiency, easy operation and space saving. Reverse
osmosis is often used for the elimination of heavy metals ion. Although the RO membranes
may be effective in the removal of heavy metal ions, the process has a very small water flux
and also consumes a significant amount of energy. Adsorptive MF or UF membranes have
emerged as an attractive means to remove heavy metal ions.
In this study, the electrospinning of chitosan (Cs) has been investigated. The problem of
chitosan high viscosity, which limits its spin ability. Therefore in this research, the chance of
producing chitosan electrospun nanofiber mats (Cs-ENM) was provided by using polyvinyl
alcohol (PVA) polymer. Electro spinning of different chitosan percentages (3 - 5% w/v) under
variation of Cs/PVA mass ratio (20/80, 40/60, 50/50, 60/40) done to achieved bead free and
uniform Cs-ENM structure.
Formation of bead-free nanofibers were achieved at, 3% w/v of Cs and 50/50 Cs/PVA ratio.
The average nanofiber diameter, porosity and average pore diameter of the optimum CST/PVA
is 105.1 ±35.1 nm, 47.1%, 0.177 µm, respectively. Glutaraldehyde have been used as crosslinker
to eliminate solubility Cs-ENM in water environments. The hot press post treatment
method was applied on nanofibrous membrane for interface stability enhancement between
them.
The effect of ENMs layer including one, three and five layer on pressure normalized water flux
(PNWF) and rejection of Cu (II) during dynamic filtration experiments was observed. It was
realized that five layer ENMs has best results, so that the PNWF and rejection of 237 L.m-2.h1
.bar-1 and 99% were obtained, respectively. Also all membranes have the ability to be used
again in the removal of metal ions; in a way that the rejection percentage of each regenerated
ENAMs only decreases by 1 to 3% and the flux recovery ratio would become more than 77%.
Keywords: chitosan/PVA, electrospun affinity nanobibrous membranes, removal of metal ions
