Recovery of metals and complexant in wastewater by shear induced dissociation coupling with ultrafiltration

Abstract

Heavy metals (Pb (II), Hg (II), and Cd (II)) in ore dressing wastewater (ODW) were selectively separated by shear-induced dissociation coupling with ultrafiltration (SID-UF) using polyacrylic acid sodium (PAAS) as complexant. Metals (Pb (II), Hg (II), and Cd (II)) were complexed with PAAS and rejected by ultrafiltration membrane at first. The effects of pH and P/M (mass ratio of polymer to metal ions) on the rejection were investigated and the suitable pH and P/M were obtained, at which the rejection arrived at almost 100%. For the recovery of metals and polymer complexant from the retained, the shear stabilities of PAA-metal (PAA-M) complexes were studied, and the critical shear rates of PAA-Pb, PAA-Hg, and PAA-Cd complexes at pH 7.0 were 2.72 × 10, 5 2.42 × 10 5 and 2.01 × 10 5 s −1 , respectively. According to the difference of the critical shear rates of the PAA-M complexes, SID-UF was used to recover Pb (II), Hg (II), Cd (II) and PAAS.

Synthesis of a Novel Water-Soluble Polymer Complexant Phosphorylated Chitosan for Rare Earth Complexation

“…C–UF has been widely used for the concentration and separation of heavy metal ions, and the used complexants are poly (acrylic acid) sodium (PAAS), copolymer of maleic acid and acrylic acid (PMA), chitosan (CS), etc. [ 13 , 14 ]. However, there are few reports regarding the separation of rare earths by C–UF.…”