硝化和厌氧氨氧化过程亚硝酸盐电化学传感研究

Electrochemical sensing of nitrite in nitrification and anaerobic ammonia oxidation processes

【目的】实时反映硝化和厌氧氨氧化(anaerobic ammonia oxidation,ANAMMOX)过程中亚硝酸盐质量浓度变化及反应动态。【方法】采用循环伏安法(cyclic voltammetry,CV)和计时电流法(chronoamperometry,CA)对模拟废水及反应液中亚硝酸盐的电化学氧化信号及其影响因素进行分析与研究。【结果】模拟废水CV测试的氧化峰电流(I_(p))与亚硝酸盐质量浓度成正比,且pH和电导率(κ)变化对I_(p)影响较小,但因CV测试用时较长,难以实时反映亚硝酸盐质量浓度变化情况;模拟废水CA测试稳态电流(I_(κ))和κ对亚硝酸盐质量浓度变化响应迅速,以I_(κ)和κ作为传感信号,可以较为准确地反映亚硝酸盐质量浓度变化情况。反应液I_(κ)和κ变化与硝化和ANAMMOX过程具有较强相关性,以I_(κ)和κ作为传感信号,可以实时反映硝化和ANAMMOX反应动态进程及亚硝酸盐质量浓度变化情况。【结论】本研究结果可有力促进硝化和厌氧氨氧化的过程控制,助力短程硝化/厌氧氨氧化(partial nitritation/ANAMMOX,PN/A)工艺的推广和应用。

[Objective]The real-time reflection of nitrite mass concentration variation and dynamic processes was executed in the course of nitrification and anaerobic ammonia oxidation(ANAMMOX).[Method]Cyclic voltammetry(CV)and chronoamperometry(CA)were used to analyze and study the electrochemical sensing of nitrite and its influencing factors in simulated wastewater and reaction solution.[Result]The peak current(I_(p))of CV tests in the simulated wastewater is proportional to the nitrite mass concentration,and changes in pH and conductivity(κ)have little influence on I_(p).However,due to the long time needed for CV tests,it is difficult to reflect the nitrite mass concentration variation in real time;the steady-state current(Iκ)of CA tests andκin the simulated wastewater respond rapidly to the nitrite mass concentration variation,and using Iκandκas sensing signals can accurately reflect the nitrite mass concentration variation.The Iκandκvalues of the reaction solution are strongly correlated with the nitrification and ANAMMOX processes.Using Iκandκas sensing signals can reflect the dynamic processes of nitrification and ANAMMOX and related nitrite mass concentration variation in real time.[Conclusion]The results can significantly enhance the process control of nitrification and ANAMMOX,and facilitate the promotion and application of partial nitritation/ANAMMOX(PN/A)process.