What’s That Smell? Wastewater Edition

Sewage is not known for its pleasant aroma, but what exactly is that smell, and what causes it? The municipal wastewater treatment process can release odors in the collection and treatment process. Wastewater is mostly water, but it also contains organic and inorganic matter, bacteria, and other microorganisms. These all contribute to processes that release gases into the air that are unpleasant and easy to smell, even at low concentrations. The common culprits are mainly sulfides, mercaptans, amines, other volatile organic compounds (VOCs). For example, hydrogen sulfide has a “rotten egg” smell and is detectable to the human nose at only 0.00047 ppm (parts per million). That’s less than less than 0.00000005%, so if even a tiny amount makes it to your nose, you are going to know it.

So, what can we do about it? A common solution is to pass this odorous air through activated carbon to capture these compounds like a sponge. Activated carbon is helpful because its readily available and works pretty well at capturing a wide range of these gases. It does have some weaknesses. Granular activated carbon doesn’t have a uniform shape or size, and this can cause problems for airflow. It prefers to absorb moisture from the air instead of some of these odors, and wastewater treatment environments are pretty humid, so odors can still get released into the air. Also, activated carbon wasn’t made specifically for this job, so it doesn’t work great against all of these gases. This is why Purafil has created “engineered media” meaning it was created specifically to solve all of these problems. It is designed to capture these specific odors better than anything else on the market, it has very uniform size and shape to prevent airflow blockage, and it works great even in humid environments. Also, it converts these odors into a harmless salt so that they don’t accidentally get released back into the air and you can test it to learn when it needs to be replaced instead of waiting for odor complaints.

Do you have a persistent odor problem? Would you like to find out when you need to replace your filter media? Contact the air quality experts at Purafil today.

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