paper

 Desalination 205 (2007) 53–61                                                

Separation of monovalent, divalent and trivalent ions from wastewater at various operating conditions using electrodialysis

Mohtada Sadrzadeh, Amir Razmi, Toraj Mohammadi*

Research Laboratory for Separation Processes, Department of Chemical Engineering,
Iran University of Science and Technology, Narmak, Tehran, Iran
Tel. +98 (21) 7724 0496; Fax: +98 (21) 7724 0495; email: torajmohammadi@iust.ac.i

Abstract

 The effect of influential factors on separation of monovalent (Na⁺), divalent (Cu²⁺, Zn²⁺, Pb²⁺) and trivalent (Cr³⁺) ions from wastewater was investigated using AMV and CMV ion-exchange membranes. Taguchi experimental design was used to plan a minimum number of experiments. A L9 orthogonal array (four factors in three levels) was employed to evaluate effect of concentration (100, 500, 1000 ppm), temperature (25, 40, 60°C), flow rate (0.07, 0.7,

1.2 mL/s) and voltage (10, 20, 30 V) on separation percent of the individual ions in the solution. The results show that increasing concentration, voltage and temperature improves cell performance; however, the separation percent decreases with increasing flow rate. At concentrations of more than 500 ppm, dependence of separation percent on concentration diminishes.