Controlling odor is one of the most challenging aspects of wastewater treatment.
The first step in wastewater odor control issues is to identify where it’s coming from and then choose the best chemistry and maintenance. Odor can be controlled by one of the following:
- Neutralization of the offending odor
- Masking of the odor
- Switching the oxygen source that contributes to the growth of bacteria
Odor is primarily due to the presences of hydrogen sulfide, but can also include mercaptans and organic acids that lend themselves to growing sulfur reducing bacteria. The bacteria generates hydrogen sulfide (H2S), a colorless gas with a foul, pungent odor similar to rotten eggs.
Odor problems in wastewater can occur anytime but are particularly problematic when combined with higher temperatures experienced in warmer months. Odor can show up in rinse waters, solid waste/sludge, collection systems (municipal and industrial), oil and water holding tanks, evaporators, secondary biological systems, incinerators, food processing and other process chemistries.
Odor Occurrences and Recommended Products
If the rinse waters in your process line are growing bacteria, there may be stagnant solids on the bottom of the tanks or high drag out of process chemistry combining with organics and encouraging bacterial growth. Keep solids to a minimum and use filtration if they build up. Hubbard-Hall’s Aquapure™ Aquapucks can be used to alleviate the odor.
Accumulation of solids at the bottom and sides of a tank can lead to odor from bacterial growth. Sulfate in the water, or a carryover of sulfur from oils, can act as a source for bacteria growth producing a sulfide odor. The best treatment for this is maintenance with Aquapure™ Bio 52L which offers an alternate oxygen source for bacteria and eliminates the source of the problem (bacterial growth).
Oil/Water Mix Odor
Waste oils collected and held in a tank may contain sulfur compounds and cause bacterial growth creating a sulfide odor. We suggest the addition of Aquapure™ Bio 20, a “friendly” bacteria and Aquapure™ Bio 52L, for odor control in flowing water, pipes, collection systems and lift stations.
Evaporator Odor and Foam
Odor can build as the water is driven off and the waste is concentrated. Because most evaporators are enclosed, sulfur reducing bacteria can flourish with low oxygen and high temperatures. Adding Aquapure™ Aquapucksor Aquapure™ Bio 52L will effectively control odor along with Aquapure™ Bubble Breaker to maintain low to no odor and foam in evaporators. Sludge in evaporators can also be a source of odor, we recommend Odor Zap for this type of odor. Odor Zap can be injected before pressing sludge to eliminate odor in sludge.
High TSS Odor
When high total suspended solids occur, Hubbard-Hall offers several products to eliminate the odors. Coupled with best practices, the Aquapure™ Bio line can help maintain a better work environment for you and your workers. These products work to replace the offending bacteria with a population of healthy, friendly bacteria which overpopulates the bad bacteria. The alternate oxygen source and special bacteria/enzymes eliminate the sulfur growing bacteria that is giving off the hydrogen gas (odor).
Best Practices for Removal of TSS and Lowering Odor:
Remove free oil from water before waste treatment and run cleaners through a coalessor if possible. Maintain system by using an Aquapure product as an odor control aid.
- UV lights in rinses can help maintain a bacteria free zone and keep odor down and solids from forming in rinses and re-depositing back on your parts or further contaminating process solutions with sulfur reducing bacteria.
- Use bag filters where necessary to keep solids out of rinses.
Additional Aquapure™ Odor Control Products:
|Aquapure™ Bio 50||Bacterial blend for food processing and treatment plants for FOG with protein, BOD and TSS|
|Aquapure™ Bio 60||FOG Enzymes and bacteria to liquefy FOG in grease traps, scum pits and lift stations|
|Aquapure™ Bio 90||Biological application for dairies or any cold water application|
|Aquapure™ NOX Down||Scrubber treatment for high NOX systems|
|Aquapure™ OE||Used in conjunction with peroxide, this catalyst controls odor by breaking the bonds of the contaminants. VTX based liquid|
|Aquapure™ Aquapucks||Easy to use and no mess. These puck like tablets control odor and break down oil and grease through enzymatic reactions|
|Aquapure™ Odor Out||Can be used in misting over solid sludge like garbage and pressed sludge to keep the odor down or out.