The Study Of Amino Acid Waste Water Treatment By The Bipolar Membrane Electrodialysis

Electrodialsis is a membrane separation technology by which wastewater can be treated and used to many special chemical processes. With the development of ion exchange membrane material, the bipolar membrane electrodialysis technology has already turned into a new research field. The bipolar membrane electrodialysis can be constructed by the combination of the bipolar membranes and conventional homopolar cation- and anion-exchange membranes.In the paper, the separation and recovery of the dilute and saturated amino acid wastewater (0.002mol/l and 0.05 mol/1) was studied in the laboratory. The experimental results as follows:(1) By the bipolar membrane electrodialysis ,the treatment of amino acid waster water is economical and efficient, meanwhile, the discharge of amino acid waster water and the recovery of valuable amino acid solution can be resolved.(2) The effectiveness of applied voltage, flow rate, temperature and loading concentration ratio on the bipolar membrane electrodialysis performance was investigated, in which applied voltage has a decisive influence on the treatment prosess. The conditions of one way processoperation were optimized in a pair of bipolar membrane. The best condition is as follows: temperature 26C, flow rate 2.51/h, loading concentration ratio 5.5:1 and applied voltage 8 V. Under the conditions of this process, the results showed that removal rate of amino acid, current efficiency and power consumption are 58.4%, 84.7%, 0.333kwh/m3 respectively. In comparison of a pair of conventional ion exchange membrane electrodialysis , the difference of removal effect is very little.(3)Under the conditions of applied voltage 25V, flow rate 51/h in five pairs of bipolar membranes circulation process, the results showed that removal rate of dilute amino acid, power consumption are88.1%,0.87kwh/m3 respectively after processing 60 min. For saturated amino acid wastewater, after processing 215 min, the results showed that removal rate of amino acid, current efficiency and power consumption are 79.7%, 87.2%, 6.09kwh/m respectively.(4)When applied voltage, flow rate, temperature was 17.5 V,5 1/h,26C respectively, the removal rate of saturated amino acid wastewater and power consumption were about 78.9%,3.675 kwh/m3 after processing 3 h. This method can reduce the costs of the membrane.Finally, the empirical model of mass transfer is as follows:. It was established to describe the character of electrodialysis when thewastewater of amino acid was separated.