화학공학소재연구정보센터
Separation and Purification Technology, Vol.154, 193-203, 2015
Bipolar membrane electrodialysis for treatment of sodium acetate waste residue
Large amounts of solid waste residue containing high salinity and a series of organic impurities are produced during the manufacturing process of dithianon in insecticide factories, posing a severe environmental pollution problem. Here sodium acetate (CH3COONa) waste residue is firstly tested by diffusion dialysis (DD) to investigate the permeability of different commercial ion exchange membranes. Selemion CMV and AMV membranes show low permeability to the organic impurities of the waste residue, and hence are chosen for the following bipolar membrane electrodialysis (BMED) experiments to regenerate acid and base. The BMED firstly uses a BP-A-C-BP configuration to select an optimized current density of similar to 50 mA/cm(2). Afterwards, four membrane stack configurations are compared including BP-A-C-BP, C-BP-A-C, BP-C-BP and BP-A-BP. In consideration of the high current efficiency, low energy consumption, and high concentrations of the produced acid/base, C-BP-A-C is a favorable configuration. Finally, the addition of a strong acid 001 *7 type of cation-exchange resin into acid compartment can substantially decrease the voltage drop across the stack and reduce the energy consumption. The C-BP-A-C configuration at 50 mA/cm(2) can have a high output (0.491 mol/L CH3COOH and 0.556 mol/L NaOH), high current efficiency (87.7% for CH3COOH and 99.0% for NaOH), and a relatively low energy consumption (22.3 kW h/kg CH3COOH and 29.7 kW h/kg NaOH). Overall, this study illustrates the practical significance of BMED process for treating sodium acetate waste residue, including reducing soil and water pollution and producing valuable products in insecticide industries. (C) 2015 Elsevier B.V. All rights reserved.