Membrane Flue Gas Desulfurization Products Of Bipolar Membrane Electrodialysis Regeneration

Experiments were carried out to regenerate NaHSO3 waste water desulfurized by membrane process using bipolar membrane electrodialysis. The regeneration rates are all above 90%. The outcome of membrane property tests were that water content was 45%,anion and cation exchange content were 2.0mol/kg and 2.2mol/kg,limiting current density was 38A/m2.The results of orthogonal experiments indicated that bulk concentration,current density , electrode rinse acidity, compartment flux , electrode rinse concentration and Na2SO4 content all had effect on NaHSO3 regeneration process. The optimum operating parameters were that current density was 40A/m2,bulk concentration was below 0.2mol/L, the acidity of electrode rinse was between 4 and 7, the compartment flux was 70L/h , the concentration of electrode rinse may as well agree with regeneration solution and a little amount of Na2SO4 could improve the regeneration rate.When the current density was increased at the constant of other parameters,the current efficiency was decreased, while the energy consumption was increased.The creepage of circuit in this experiment is less than 0.46%. After using for about 50 hours,the performance of bipolar membrane decreased markedly.Unit voltage and energy consumption increased.