Design Of Water Chemical Oxygen Demand Detection System

This paper presents an automatic system for water Chemical oxygen demand detection.The system uses modern information technology to measure the degree of water pollution.Chemical oxygen demand is one of the indicators of water pollution,it refers to mass of oxidizing agent consumed in the oxidation of water samples by oxidant under certain conditions.Chemical oxygen demand can indicate the concentration of reducing substances in the water.The reducing substances in water include organic matter and various reducing ions,the degree of water pollution can be known by the concentration of reducing substances.The system is designed for the determination of Chemical Oxygen Demand Permanganate index.The Permanganate index is measured by Spectrophotometry.Measuring the concentration of potassium permanganate can quantify the extent of water pollution.The system can be used to measure the pollution degree of surface water and drinking water.It can improve the detection precision and save manpower.The system is divided into three parts: Detection Terminal,service terminal and user terminal.The detection terminal is composed of MCU,chemical process control,communication and touch screen.The functions of the detection terminal include chemical process control,sample detection,and human-computer interaction through touch screen.Users can view data and configuration parameters through the touch screen.The server is responsible for receiving and storing the data uploaded by the detection terminal and the configuration data uploaded by the user terminal.The user terminal reads the data from the server and uses the graphical interface to process and display the data.The detection terminal can be configured through the user terminal and the configuration data can be uploaded to the server.The system is developed according to the Internet of things architecture,and the online detection is realized.The detection terminal uses Ethernet to connect to the Internet of things.To improve the system reliability and expansibility,the system hardware and software are modularized to improve the system reliability and expansibility.The system is suitable for the determination of the Permanganate index of drinking water,surface water and other lightly polluted water sources.The detection terminal uses 525 nm light source to measure the absorbance of the potassium permanganate solution to get the solution concentration.The absorbance measured by the system is linear with the solution concentration,and the test results show that the system can meet the requirements for the determination of Chemical Oxygen Demand Potassium permanganate by Spectrophotometry.