Thermal mass flow meters provide accurate gas flow measurement and monitoring of air, oxygen, ozone, and digester gas in various applications at water and wastewater treatment plants.
- Dissolved Oxygen Feedback Loop Control
- Air to Primary Treatment Basin
- Air to Secondary Treatment Basin
- Digester Gas
- Oxygen and Ozone Monitoring
Air to Basins and Dissolved Oxygen (DO)
In wastewater treatment, air is introduced to oxygenate the mixture to facilitate the growth of beneficial aerobic bacteria, which breaks down waste. Older treatment systems manually inject air through drop lines into the basins. Unfortunately, in most instances, no measurement or control, or airflow rate is determined, and there are massive inefficiencies. Current aeration systems use air diffusers where flow meters can be utilized to balance the flow to different sections of the aeration basin.
By measuring the air flow rates with a thermal mass flow meter and outputting the results to dissolved oxygen (DO) feedback control loop, the entire process can be automated which can save substantial energy.
Downstream of the aeration basins, digesters further breakdown waste and release digester gas (typically 65% methane and 35% carbon dioxide). At many plants, digester gas is conditioned for use in internal combustion engines to produce electricity for on-site use. In other situations, the digester gas is sold to an outside company for cogeneration production.
Thermal mass flow meters are used to monitor flow rates to digester gas conditioning, compressor, and fueling stations. If the digester gas not used for power production is flared, flow meters can measure the flow of digester gas to the flare.
Oxygen and Ozone Monitoring
Oxygen/ozone and chlorine may be used in the purification of water. Thermal mass flow meters can measure oxygen and ozone in the systems that do not use chlorine. Additionally, Sage Metering supplies flow metering to ozone-generating manufacturers, and they use the meters in water purification systems.
For more information, visit Wastewater Treatment Plants – An Industry Guide for Thermal Flow Meters for more insight into the applications for wastewater treatment plants.