双极膜电槽与变频不对称脉冲方波技术在电合成高铁酸盐中的应用

Bipolar Membrane Electrolysis Cell and Technology of Dissymmetrical Square Wave with Alternate Frequency for Electro-Generated FeO_4^(2-)

在CS-CMC双极膜电槽中,以多孔圆筒铸铁为阳极,结合变频不对称脉冲方波技术电解制备水处理剂高铁酸盐。IR分析表明,该聚合物膜两极分别含有-N=CHR、-COO-官能团。CS-CMC双极膜的溶胀率较小,能稳定存在于浓酸、浓碱溶液中。在电极上迭加变频不对称脉冲方波可及时去除阳极表面的氧化膜。与平板铸铁阳极电解槽相比,多孔圆筒铸铁阳极电解槽可得到更高的电流效率和更高浓度的高铁酸盐。在14 mol/L的NaOH溶液中,室温以5 mA/cm2的电流密度、脉冲方波频率2 Hz电解6 h,电流效率平均为51.1%,高铁酸盐浓度达37 mmol/L。

This paper focused on the usage of dissymmetrical square wave with alternate frequency for electro-generated FeO4^2-. In order to obtain a better distribution of current efficiency, the cylinder electrolytic bath was constituted by double cathode and porous cylinder cast iron as anode, using CS-CMC bipolar membrane as septum. The mechanical strength and chemical stability of CS-CMC BM is better than that of CS or CMC membranes in the acid and alkali solution. CS-CMC BM contained --N=CRH2^＋and --COO functional groups in the CS-CMC BM was confirmed by FT-IR spectrum. The oxidation layer on the cast iron anode was demolished in time when the dissymmetrical square wave was applied. After 6-hour electrolysis at 2 H2 and 5 mA · cm^2, 37.0 mmol ·L^-1FeO4^2 was generated and the corresponding current efficiency was 51.1%.