电化学氧化除氨氮过程中羟基自由基及中间产物定量分析

采用高效液相色谱对电化学氧化除氨氮过程,不同电流密度,Cl-浓度及初始pH值的·OH进行定量检测和分析,同时,对不同初始pH值和电流密度下,电化学氧化除氨氮的中间产物进行了定量分析,结果表明:·OH产生量与电流密度成正比,当有Cl-存在,且在碱性条件下会抑制·OH的产生;初始pH值为偏碱性时,NO2-和氯胺的产量均有所增加.建议电化学氧化脱氨氮过程,尽量保持溶液pH值在中性或酸性条件下;电流密度对氨氮电化学氧化过程中各中间产物的量有着较大影响,在电流密度为10mA/cm2时,活性物质产量最高,且有害中间产物产量最低.

The quantitative analysis of hydroxyl radical produced and intermediate products in the process of electrochemical oxidation for ammonia removal

In the process of electrochemical oxidation for ammonia removal, the concentration of hydroxyl radical (·OH) was detected and quantitatively analyzed by high performance liquid chromatography in different current density, chloride ion (Cl-)concentration and initial pH value. The concentration of ·OH produced was direct proportional to current density, and the production of ·OH would be inhibited under the conditions of existence of Cl- and alkaline. Meanwhile, the intermediates were detected and quantitatively analyzed by spectrophotometry and titration in different initial pH and current density. When the initial pH was alkaline, NO2- and chloramine, as noneffective intermediate products, would increase. Therefore, electrochemical oxidation of ammonia should be at neutral or acidic conditions. In addition, the current density had great effect on intermediates of the electrochemical oxidation of ammonia. Higher active substances and lower harmful intermediate products yielded at current density of 10mA/cm2.