电化学法制备高铁酸盐条件优化的研究

Optimization on the Process of Electrochemical Ferrate( VI) Synthesis

研究了电流密度、电解液浓度、电解液添加剂、电解时间等因素对电化学法制备高铁酸盐产品浓度和电流效率的影响,并从实用性出发,通过对比单位质量高铁酸盐所引入碱量的多少,来确定最佳电解液浓度。研究结果表明,电解时间控制在3 h内,电流密度为17.2 m A/cm^2,NaOH电解液浓度为14 mol/L时,高铁酸钠浓度最大,电流效率最高。而从实用性角度,采用8 mol/L的NaOH电解液生产高铁酸钠时,等量高铁酸钠引入碱量最小,即对受纳水体pH值影响最小。在电解液里添加0.01%~0.1%NaCl,对电流效率有一定的提高作用,生成的高铁酸盐浓度提升了14.90%;而当添加0.01%~0.1%Na_2SiO_3时,电流效率显著提高,高铁酸钠产品浓度提升了40.70%。研究中发现,在低浓度电解液中,添加NaCl或Na_2SiO_3效果更为显著。

Ferrate（Ⅵ） was synthesized by electrochemical method. Factors like electrolysis duration,current density,and electrolyte concentration that influence the ferrate concentration and current efficiency were studied.By comparing the different amount of alkali that was introduced into the received water body per unit mass of ferrate,practicality was evaluated. The results show that if the electrolysis time is controlled within 3h,the anode surface can avoid to be oxidized,and higher ferrate concentration could be gained.The highest current efficiency was obtained at 14mol/L of NaOH electrolyte.However,in water treatment,when 8mol/L of NaOH was used to produce ferrate,with the application of the same amount of ferrate,the alkali had the least effect on the pH of the receiving water.NaCl（ 0.01% ~ 0.1%） as an additive of electrolyte can enhance the current efficiency,which made the ferrate concentration improved by 14.90%.While Na2SiO3（ 0.01% ~0.1%） as an additive has a significant positive effect on the current efficiency,which made the concentration of the product improved by 40.7%.In the lower concentration of electrolyte,the additive has more remarkable effect on current efficiency.