烟气吸收液中亚硝酸铵的电化学氧化处理技术

Electrochemical Oxidation of Ammonium Nitrite in Absorption Solution of Flue Gas

为实现燃煤电厂烟气脱硫、硝和汞一体化工艺中吸收液副产物亚硝酸铵的废物利用,采用电化学氧化处理技术将吸收液中亚硝酸铵转化为硝酸铵.采用极化曲线、循环伏安曲线和恒电流法等多种电化学测试方法评价和选取电极材料,探讨电解液组成的影响,得到优化的电化学氧化工艺参数,并用化学分析法验证了电化学氧化处理效果.

In order to make full uses of ammonium nitrite in absorption solution from flue gas simultaneous desulfurization, denitrification and demercurizafion processes, here the electrochemical oxidation method was used to transform ammonium nitrite into ammonium nitrate. By using polarization curve, cyclic voltammogram and galvanostatic methods, suitable electrode materials were evaluated and chosen. The influence of electrolyte composition was discussed and the appropriate process parameters were obtained. Finally, the effect of electrochemical oxidation was confirmed by chemical analysis method. In 0.05 mol .L-l NaNO2 ＋ 0.05 mol·L^-1 （NH4）2SO4 simulated absorption solution （5 L, pH = 7.0） and by using titanium cathode and carbon fiber brush anode, the transformed efficiency of nitrite ion reached 72% atter 16 h with the oxidation current of 600 mA.