基于环境管理需求的COD在线监测技术改进建议

COD Online Monitoring in China: Demands,Applications and Usage Suggestions

利用政策与管理需求差距分析、现状调研与实地监测试验的方法,综合分析中国环境管理中对污染源COD在线监测技术的需求转变、常见的重铬酸钾法和UV法在实际应用中的常见问题;通过重铬酸钾法和UV法在线监测及国标手工分析方法的实地试验结果比较,分析如何改进并充分发挥不同在线监测技术的环境管理支撑优势。分析结果显示,我国对COD在线监测技术存在浓度和总量监测的双重需要,但实践中存在准确度不足以支撑执法、监测频率难以捕捉冲击负荷和测算总量、废液污染以及产品质量等问题。污水厂试验显示,UV法与手工分析法一致性较好;UV法监测频率优势突出,可充分反映出水水质连续、突变、短时平衡过程,还可以预警出水水质和分析水质恶化原因,协助污水厂优化运行。可以从技术、应用模式和监管体系等方面进行改进,以发挥不同COD在线监测技术的优势。

The changing demands of environmental management on COD online monitoring and the application problems of UV method and potassium dichromate method in China were researched by analyzing the gaps between the policy and the demand and conducting field experiments. By comparing the results of UV method, potassium dichromate method and manual methods, it was explored how respective method could be better utilized for supporting environmental management. The results showed that COD online monitoring may be used for discharge and total amount control in China, though there are problems of inadequacy in accuracy and frequency, secondary pollution and instrument quality. The UV method and manual method had good correlation. The higher frequency of UV method allowed it to capture the continuous, sudden and delicate change in COD, predict effluent quality and explain degradation, ultimately optimizing the plant operation. Improvement in technology, application mechanism and supervision could further enhance the advantages of different COD monitoring methods.