High Selective Separation of Heavy Metals in Wastewater by Shear Induced
Orderly Dissociation Coupling with Ultrafiltra
Abstract
Heavy metals M (Cr (III), Ni (II), Cu (II), Zn (II)) in nickel plating
wastewater were recovered by complexation-ultrafiltration (C-UF) with
the complexant PMA. The important factors pH and PMA/M mass ratio (P/M)
on metals rejections were investigated, and all rejections could reach
to 98% at pH 6.0 and P/M 8. Besides, the shear rate () distribution on
the membrane surface was analyzed by CFD revealed that increased along
the radius.The criticl shear rates (c) of PMA-M complexes were
calculated to judge the shear stability of different complexes,and c of
PMA-Cr, PMA-Ni, PMA-Cu and PMA-Zn complexes were 1.14×105, 1.48×105,
2.07×105 and 1.21×104 s-1 ,respectively. Furthermore, the pairwise
separation coefficients of metals were calculated, and the maximum of
βZn/Cr, βCr/Ni and βNi/Cu are 95.5, 42.0 and 47.3. The high selective
separation of heavy metals and PMA were achieved by shear induced
orderly dissociation coupling with ultrafiltration(SIOD-UF).