Experimental Study For Ionic Membrane Electrodialysis Method In The Trona Brine Desalting And Ion Chromatography Analysis

Salt of the trona brine seriously affect the soda ash recycling in theproduction process of soda ash. Salt of the trona brine is not only resultedin low quality of soda ash recycling and wastes a lot of resources.Consequently, the trona brine should be desalted.This paper preliminarily studies the feasibility of ion-exchangemembrane electrodialysis for the trona brine disposal and recycling, andexplores the conditions of the ion exchange membrane electrodialysis fordesalination test. The ion chromatography is used for analysis test results.Firstly, the test selects electrodialysis system which uses thehomogeneous cationic and anion exchange membrane with the bipolarmembrane. As a result, we get this conclusion that the2-cell bipolarmembrane electrodialysis equipment is best accorded with indicator ofdesalination of the trona brine.The paper investigates the effect of the various operating factors onpower consumption, current efficiency and salt rejection. The resultshows that: the medule voltage, flow, temperature and concentrationimpact desalination of the trona brine by the2-cell bipolar membrane electrodialysis. The medule voltage has maximum influence on theperformance of the trona brine. Based on the experiment by orthogonaldesign, the optimal operating conditions were obtained. The optimaloperating conditions are24V operating voltage,20°C temperature,3.5L/hflow,2.5mol/L feed concentration. This experiment's optimal operatingconditions gets97.4%desalination rate,85%current efficiency, and0.3026kWh/kg power consumption.Based on ion chromatography, the content of NaCl in the trona brineis detected. This paper establishes the ion chromatography alanysis ofNaCl in the process of desalination. The result shows that standardcomposition of the sample need change in determination of the tronabrine to avoid the influence of Na2CO3and NaHCO3for Cl-determination of the trona brine. We optimize the chromatographiccondition on the foundation. If we increase the concentration of the eluent,the time is shorted0.934min. If we change the flow speed of the eluent,the time is shorted1.158min. If we add organic reagents acetonitrile, thetime is shorted1.489min. And if the three are used, the time will beshorted3.315min. The Result indicates: it has high efficiency.