关键词: Pb²⁺, Zn²⁺, 丙烯酸-马来酸酐共聚物, 超滤, 选择性分离, 竞争络合

Abstract: Polyelectrolyte-enhanced ultrafiltration (PEUF) was investigated to separate Pb²⁺ and Zn²⁺ from aqueous solutions by PMA as a chalenting agent. Effects of pH, concentrations of PMA and the added sault on seperation rate (S_r) was studied. S_r inceased gradually before the PMA concentration reached 200 mg/L, and then it decreased, the best S_r value is 54.47%. At pH between 2 to 6, S_r increased gradually with pH reached a maxium value, and then deceased, It was preferable for the selective separation to control pH=4, and the S_r value is 71.34% at this time. PMA and pH play important roles in competitive complexation between Pb²⁺ and Zn²⁺, the increased concentration of PMA and pH enhanced the competitive complexation, when PH reached to 5, PMA concentration is 200 mg/L, the competitive complexation of Zn²⁺ was lowest. The concentration of the added sault have an important infect on S_r. The experiment was performed at pH=4 and PMA=200 mg/L, controlled the concentration of Sodium sulphate from 0.01 to 0.08 mol/L,When the concentration of sodium sulphate is 0.06 mol/L, S_r reached the best. The addition of Na₂SO₄ weakened the competitive complexation effect of Zn²⁺.

Key words: Pb²⁺, Zn²⁺, PMA, ultrafiltration, selective separation, competitive complexation