Rs. Juang et Mn. Chen, REMOVAL OF COPPER(II) CHELATES OF EDTA AND NTA FROM DILATE AQUEOUS-SOLUTIONS BY MEMBRANE FILTRATION, Industrial & engineering chemistry research, 36(1), 1997, pp. 179-186
The removal of Cu(II) chelates of ethylenediaminetetraacetic acid (EDT
A) and nitrilotriacetic acid (NTA) from aqueous solutions was studied
by batch ultrafiltration (UF) with the help of poly(ethylenimine) (PEI
). The Amicon regenerated cellulose YM10 and YM30 were used as ultrafi
lters. Experiments were performed as a function of aqueous pH, the con
centration ratios of chelating agent to Cu(II) ions (alpha) and of PEI
to Cu(II) ions (beta), and the applied pressure (Delta P). In general
, the removal of Cu-EDTA chelates was more effective compared to that
of Cu-NTA chelates. Under the conditions tested (pH 4, Delta P = 2.04
atm, [Cu2+] < 4 mM), the removal efficiency was higher than 97% for Cu
-EDTA chelates when alpha > 0.5 and beta > 10 and higher than 96% for
Cu-NTA chelates when alpha > 0.5 and beta > 20. The effect of the pres
ence of inorganic salts on the removal was also investigated. Finally,
the membrane fouling during UF was analyzed by modified fouling index
, and the regeneration of PEI was examined.