Currently, most of the changes in COD in sewage are monitored in real-time using online detectors, which can quickly detect changes in organic pollutants in the water body, and can be immediately treated in case of problems to prevent worsening of water pollution. However, to provide accurate water quality monitoring data with online COD detectors, attention needs to be paid to many aspects, such as equipment, maintenance, and water inflow. Today, we will talk in detail about the impact of inlet water temperature on the online COD water quality detector.
Influence of Inlet Water Temperature on Online COD Detector
Generally, the COD detection of water samples using the chemical method requires high-temperature digestion and cooling to room temperature before testing, so the impact of small changes in inlet water temperature is not too significant. However, everyone should pay attention to the following situations.1. Chemical reaction rate
COD detection involves oxidation reactions, and the rate of chemical reaction usually increases with increasing temperature. According to the theory of chemical kinetics, when the temperature increases by 1 degree Celsius, the reaction rate may increase by about 10%. Therefore, if the temperature of the water sample increases, the oxidation reaction rate involved in COD detection may accelerate.
2. Unstable reaction conditions
COD detection needs to be carried out under certain reaction conditions, including reaction time, oxidant dosage, reaction pH, etc. Changes in water sample temperature may affect these reaction conditions, leading to unstable reaction conditions. For example, when the water temperature rises, the reaction time may be shortened, the amount of oxidant may need to be reduced accordingly, and the reaction pH may change. These changes may have an impact on the COD detection results, leading to high or low COD values.
3. Decrease in dissolved oxygen content
Increasing the temperature of water samples can lead to a decrease in the content of dissolved oxygen, which is commonly used as an oxygen source for oxidation reactions in COD detection. If the temperature of the water sample is unstable, changes in the dissolved oxygen content may be affected, resulting in insufficient oxidation reactions, leading to low COD detection results.
4. Water condensation occurs inside the equipment
If the difference between the inlet water temperature and the ambient temperature is too large, water vapor will condense inside the equipment, forming water droplets that will accelerate the aging of components inside the equipment, causing problems such as instrument failures.
I hope that these contents can give everyone a clearer understanding of the impact of inlet water temperature on the online cod detector.
