NRB stands for Nitrite Reducing Bacteria, which is a test that detects ammonia formed when nitrite is reduced

 NRB stands for Nitrite Reducing Bacteria, which is a test that detects ammonia formed when nitrite is reduced. The test is based on the biochemical pathway that forms ammonia (NH3) from the reduction of NO2. 

Here are some other things to know about cooling towers: 

Types

Cooling towers are categorized as either natural draft or mechanical draft. Natural draft towers use large concrete chimneys to introduce air, while mechanical draft towers use fans to force or suck air through the water. 

Size

Cooling towers can range in size from small rooftop units to very large structures that can be over 200 meters tall and 100 meters in diameter. 

Emissions

Cooling towers are often thought to emit smoke or harmful fumes, but in reality, they mostly emit water vapor. 

Scaling

Scaling can be prevented by monitoring the conductivity of the cooling water, ensuring that the levels of certain salts and chemicals don't exceed solubility limits, and implementing a regular blowdown treatment schedule.