Development of new COD sensor

• Main Author: Luo, Zhengyang.
• Other Authors: Cai Wenjian
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Control and instrumentation
• Online Access: http://hdl.handle.net/10356/17943
• Institution: Nanyang Technological University

The Chemical Oxygen Demand (COD) is the amount of oxygen consumed to completely chemically oxidize organic water components to inorganic end products. Water quality is determined by factors such as physical state, chemical concentrations and biological organisms. COD which reflects the total pollution load in the water samples is a very important parameter in both water treatment and assessment. Drawbacks of existing methods are either time-consuming or cause secondary pollution. A novel COD sensor based on electrochemistry principle with multiple electrodes and O3 as oxidizing agent was proposed. The O3 used can be generated from ambient air. A great benefit of using O3 is that O3 decomposes to O2 in half an hour and thus no pollution is produced. The portable device can be used for online monitoring and provide accurate results over a wide range of COD values. In this project, the COD sensor under development is to be tested as well as sample testing done so as to facilitate future integrations with the ozone generator that will be a part of the sensor. The basic control and monitoring system of the COD sensor is tested and its various features worked on so as to make it more user-friendly and to enhance its performance. In addition to the improvements to the COD sensor, the results obtained from the tests performed on both the sensor and parts of the sensor are discussed. Since there is a growing concern for the purity of water, water specialists dealing in fields such as ecology studies, environment protection and waste treatment need an effective way to determine the water quality. High demands for such a COD sensor on the market thus leads to a high potential to commercialize the product.