Continuous Dissolved Oxygen Sensor Monitor in Surface Water

Dissolved oxygen is oxygen that exists in molecular form dissolved in water. Dissolved oxygen is an important indicator for measuring the water quality of surface water, including rivers, lakes, reservoirs, fish ponds and other water bodies. The dissolved oxygen in clean surface water is generally close to saturation, but if the water body is polluted by organic and inorganic reducing substances, the dissolved oxygen in the water will be consumed. When the rate of oxygen consumption is greater than the rate of oxygen replenishment in the atmosphere, the dissolved oxygen gradually decrease and approaches zero. At this time, anaerobic bacteria multiply and the water quality deteriorates, causing fish and shrimp to suffocate and die. Generally speaking, as the temperature increases, the dissolved oxygen saturation decreases; as the pressure increases, the saturation increases; as the salinitity increases, the saturation decreases. How to continuously monitor the dissolved oxygen value of surface water? We usually use an Online Dissolved Oxygen Sensor. Daruifuno OPD790 is a digital sensor that can continuously measure the dissolved oxygen value of water quality. It uses optical fluorescence method and does not require reagents or oxygen consumption. It is plug and play. When monitoring surface water, you can use the MCC200 series multi-parameter water quality analysis controller to simultaneously monitor the dissolved oxygen, pH, turbidity and conductivity values of surface water.

Dissolved oxygen monitoring of surface water is very necessary. According to actual monitoring experience, the vast of majority of surface water data are lower than saturation. The quality of surface water can even be roughly judged from the DO value detected by the Dissolved Oxygen Sensor. Clean surface water has higher dissolved oxygen. If the dissolved oxygen is lower than 2mg/L, it can basically be judged that the water quality has been seriously polluted.

Specification

The saturation of gas in water means that the gas dissolved in water has reached the maximum value under a certain temperature and pressure. This value is a fixed value under certain conditions and is related to the partial pressure of oxygen in the air, atmospheric pressure, temperature and salt content.
For example, under standard atmospheric pressure and 25°C, the saturation of dissolved oxygen in pure water is 8.25 mg/L. If under this condition, the dissolved oxygen content in the water is >8.25mg/L, this phenomenon is called supersaturation of dissolved oxygen.
Although the phenomenon of supersaturation in surface water monitoring is not a common phenomenon, it occurs from time to time in actual monitoring work. According to experience and relevant data, the supersaturation phenomenon of dissolved oxygen in monitoring generally occurs under higher temperature, sunny and sunny weather conditions and in water bodies with obvious eutrophication. The content of phosphorus and nitrogen in water bodies is, to a certain extent, a controlling factor in the number of plankton. The increase in nutrients in the water and the eutrophication of the water body will promote the vigorous growth of autotrophic organisms. The number of individuals of certain algae will increase rapidly, while the types of algae will gradually decrease. There is sufficient light on the surface of the water body, and certain algae will grow and reproduce in large quantities under appropriate conditions. The growth and reproduction of algae require photosynthesis. A large amount of growth and reproduction will produce a large amount of oxygen, making the surface layer of the water supersaturated with dissolved oxygen. In addition, supersaturation of dissolved oxygen will also occur in turbulent areas of the river, especially in sections with large drops. This is caused by the rapid mixing and replenishment of oxygen from the air into the water during the violent movement of the water body.

If you are interested in dissolved oxygen monitoring of surface water, please contact us for more information on dissolved oxygen sensors. Delfino company focuses on the R&D and production of water quality analysis instruments. Our measurement parameters include pH, ORP, conductivity, TDS, salinity, dissolved oxygen, COD, ammonia nitrogen, turbidity, chlorophyll, blue-green algae, residual chlorine, and chlorine dioxide. wait. In addition to ORP sensors, our main products include Ph Orp Analyzer, Conductivity Analyzer, Turbidity Analyzer, Cod Analyzer, Dissolved Oxygen Analyzer, ammonium analyzer, chlorine analyzer, etc.