The Research On COD Measurement Technologies Based On Multi-parameter Cross-coupled Analysis

Chemical oxygen demand(COD)is a comprehensive index to evaluate water pollution and an important water quality parameter to measure the degree of organic pollution.The research of COD measurement technology has important theoretical significance and practical value.At present,the measurement method of chemical oxygen demand can not meet the needs of outdoor long-term water quality monitoring.Cod sensor needs frequent manual calibration and maintenance,resulting in a lot of waste of resources.It is found that in the same water environment,the COD value of water has a strong correlation with water quality parameters such as p H,dissolved oxygen,turbidity and redox potential.In this paper,a COD measurement technology based on multi parameter coupling cross analysis method is proposed,which can estimate COD value through other water quality parameters,so as to provide basis for automatic calibration of COD sensor,reduce manual calibration times and use cost.According to the above analysis,this paper mainly focuses on the following aspects:Study on the multi parameter correlation of water quality and design of water quality parameter model.The steps of water quality parameter model design are defined.Through literature research and mechanism analysis of measurement process,the correlation analysis of historical monitoring data is carried out to determine the dominant and auxiliary variables of water quality parameter model.According to the measurement process,the abnormal value determination method is put forward to complete data cleaning and data conversion.Design the model structure,select the appropriate modeling method,establish the water quality parameter model,and use the processed sample data to complete the training and correction of the model.Design and implementation of COD online estimation system.COD online estimation system is the hardware platform of water quality parameter model,including hardware circuit design,lower computer program design and upper computer software design.The lower computer is responsible for collecting and analyzing the water quality parameter information of auxiliary variables,and then upload it to the cloud by 4G communication.After receiving the data,the upper computer estimates the COD value online and displays it by calling the water quality parameter model.System testing and experimental research.In the laboratory environment,the functional modules are verified and tested,and the system joint debugging test is completed.On this basis,the lake experiment is designed and completed,and the experimental situation is summarized and analyzed,and the experimental results are evaluated.