Electrophoresis Separation Of Charged Species Featuring Vertical Electric Field

Arising from more and more severe environmental pollutions, fresh water resources suffering from being lack of supply, becomes a problem. Exploration of new technologies is of importance to effectively solve this situation, in particular those for desalination of seawater. The electrophoresis apparatus of vertical electric field was applied to investigate the desalinating synthetic seawater, providing a new method for desalination. In addition, this electrophoresis technology can also be applied to separate the organic charged particles, that is separation of the organic pollutants in TNT (Trinitrotoluene) red water. It also provides theoretical evidence for the TNT red water treatment.In this manuscript, a home-made electrophoresis apparatus of vertical electric field, was applied to investigate the desalinating synthetic seawater, on basis of chlorine anion. Effect of initial concentration of chlorine anion, retention time and applied voltage on the desalination ratio, energy efficiency (mass of collected chlorine anion at positive electrode region per electric power) and distribution ratio was investigated.The electrophoresis apparatus has four outlet regions of positive region, negative region, central region, and adjacent region between two electrodes, of which central region represents target collection region for desalinating synthetic seawater. It showed that with an increase in initial concentration of chloride anion at inlet, the desalination ratio at central region reduced and the energy efficiency gradually increased, and the distribution ratio at positive region decreased, but that at the rest three regions increased. When retention time increased, the desalination ratio at central region apparently increased up to 69.5%, the energy efficiency gradually reduced, the distribution ratio at central region and negative region decreased, but that of positive region and adjacent region between two electrodes increased. If the applied voltage increased, the desalination ratio at central region gradually increased up to 13.9%, the energy efficiency slowly reduced, the distribution ratio at positive region increased, that at negative region and adjacent region between two electrodes slightly decreased, and that at central region increased and decreased afterward.In order to study the treatment effect of TNT red water by the electrophoresis apparatus, the simulation experiment of pure subst ances 2,4-diaminotoluene under different pH was investigated. Then the optimal conditions of iron-reduced TNT red water were investigated. Under the optimal reduction conditions of TNT red water, macroporous resin was used to separate the organic pollutants and inorganic salt and obtained the organic pollutants by elution of sodium hydroxide. The eluate was fed into the electrophoresis apparatus to investigate the distribution of aniline and COD.The simulation experiment results showed that, organic pure substance 2,4-diaminotoluene at different pH showed that when the pH reduced at inlet, positive charge of 2,4-diaminotoluene gradually increased and the mass of collected 2,4-diaminotoluene at negative region increased. The optimal conditions of reduction reaction were that pH was 1, iron mass was 15 g and reaction time was 4 h at shaker’s temperature of 25 ℃. TNT red water was reducted by iron at the optimal reduction conditions, and by adsorption desorption to obtain the eluent, and then diluted the eluent 3 folds with deionized water. The pH of eluent diluted is 1.9, the concentration of aniline compound and COD are 8.8 mg/L and 137.9 mg/L, respectively.Electrophoresis apparatus for treating TNT red water showed that the concentration of aniline at negative region was less than 1.0 mg/L (except B4 oulet), COD values were lower than 13.8 mg/L.The concentration of aniline and COD were lower than initial values at adjacent region between two electrodes, but that of positive region significantly higher than the initial concentration. And central region was similar with initial concentration. It proved that under the above experimental conditions, organic pollutants in TNT red water migrated to the positive region. And aniline compounds, COD and color effectively wass removed at negative region.