Odour Control


Odour Control Treatment

Odours in wastewater treatment systems are commonplace and many odours are actually signs of a larger problem that can be avoided. When odours become strong enough to be easily noticed, it’s almost always a sign that something in the treatment process is not working right, and fixing that issue will naturally result in a drop in odours. Uncovering the reason behind the odour is the first step to wastewater odour control and prevention.

As a wastewater system ages, sludge begins to accumulate on the bottom. This sludge is usually composed of forms of BOD that the bacteria were not easily able to digest due to it being mostly insoluble. Eventually this insoluble BOD sinks to the bottom, where it joins dead bacteria, live bacteria, and small amounts of inorganics to form a sludge layer. This process happens faster during colder months when the bacteria are digesting material at a fraction of the rate they normally do.

As the sludge builds up in thickness, only the upper layer remains oxygenated, leaving the rest anaerobic.  Anaerobic environments are a hub for odours and this is where a significant amount of wastewater odours are generated, then rise up through the sludge and water column into the atmosphere.  The thicker the sludge, the more odours are generated so reducing sludge layers is one of the keys to wastewater odour control and our range of sludge reduction products will do just that.

Another common cause of odour in a waste water treatment system is low dissolved oxygen due to insufficient aeration.  Our wide range of wastewater aeration systems can solve this problem.  

Odours may also be generated by the breakdown of complex organics such as long chain fatty acids in the wastewater process.  This can be commonplace in industrial and food processing wastewater treatment systems where the problem is intensified as these systems are usually imbalanced with one source of BOD e.g proteins (dairy plants), fats (rendering plants), amines (chemical processing), fibres (paper mills) and sugars (beverages).  These complex organics must first be broken down into smaller compounds by bacteria and this process can create odours.  When fatty acids and other forms of BOD are creating odour it’s best to accelerate the breakdown of these forms of BOD by introducing bacteria and nutrients as far upstream in the wastewater treatment system as possible.

While the above mentioned wastewater odour control methods are effective, they can take anywhere between a week to a month to control the odour so if you need a more immediate result then an odour neutralising product may be required.  These are concentrated blends of essential oils that bind to and neutralise odorous compounds; they don’t just mask odours like deodorisers do, they eliminate them.  Unfortunately these wastewater odour neutralisers won’t prevent new odours from forming so they should be followed up with some of the biological water treatment methods described above.  

Odour Control Products

Subscribe to our Newsletter