COD Electrochemical Detection Development Of A Three Electrode System

COD (Chemical Oxygen Demand, referred to as COD) of water environment monitoring in the most important indicator of organic pollution, which can be used to determine the relative content of organic matter in water, its role in body temperature with a doctor to determine the general health status of people somewhat similar, so it is not a single meaning of the indicators. For the river and industrial wastewater and sewage treatment plants for the effect evaluation is an important parameter they pass too. Chemical oxygen demand is strong oxidant water easily oxidized substances reducing the amount of oxidant consumed, the results converted into the amount of oxygen to mg/L account. It is characterized by reducing substances in water comprehensive index.Effective environmental monitoring of key environmental testing of advanced technology and equipment, as well as accurate and reliable monitoring data, there is no high-tech and environmental monitoring equipment, can not carry out environmental monitoring, environmental protection and control of scientific evidence will be lost. So to the economic development while protecting the environment for human survival, accelerate the research and development of new technologies in environmental monitoring is particularly important with new equipment. This is a sustainable economic development can ensure the high quality of life is closely related with human, and is of great technological and economic significance of the research.Paper introduces the development of electrochemical detection COD status and development trends, and characteristics of detection given the significance of this issue. And through access to technical information on research, summed up the COD electrochemical detection is presented to the advanced methods of detection of COD that studied this issue three-electrode detection in the country has a more advanced level. Secondly, the paper describes electrochemical detection COD measurement principle and hardware system architecture.Paper focuses on the electrochemical COD Detection of three-electrode system development and hardware design COD detection of electrochemical sensors and each unit carried out a detailed analysis of the circuit, especially for control of three-electrode system, a constant potential circuit multi-program design, and by experimental analysis to select the best design. Constant potential circuit design is the key to maintain the working electrode and reference electrode of constant potential between the same, to obtain accurate voltage. Used in the design of electro-chemical sensor is a new material used in boron doped diamond (BDD), a relatively traditional electrode, BDD film electrode has a potential bandwidth, high oxygen evolution potential (up to 2.8V), low background current, chemical and electrical high chemical stability, low organic matter adsorption on the electrode surface, excellent corrosion resistance characteristics of media. Therefore, the electrochemical sensor is the subject of the main part of the experiment. According to the characteristics of three-electrode system, on the topic of the working electrode (WE), reference electrode (RE), auxiliary electrode (CE) made a detailed analysis,and contact the external circuit debugging the final conclusion.