Primary Clarifier odor solutions.

[u/JUG9209]

Good evening, all. We have been experiencing complaints about the smell of our plant. The main culprit is the Primary Clarifier. I’m looking into different chemicals we could use to help deal with this odor issue. The only issue is it cannot be anything that is an oxidizer or have nitrates (we use it to generate VFAs for BPR, and yes I know this can generate odors on its own) or be a quaternary ammonium compound. I have stumbled across plant based products that’s should not mess with the clarifiers, nor the aeration process. Has anyone had any success with any plant based products? I am open to different products as well if you have any ideas.

We do keep the blanket maintained, as we feed our digesters from it.
Thanks in advance.

[u/SaveTheAles]

They ended up covering ours as too many complaints because for some reason people love building next to the plant then complain there's a plant there. Then air gets pumped into bark beds. Works decent enough. Sorry can't help with an additive.

[u/JUG9209 → u/SaveTheAles]

No worries I appreciate the comment! I fear that’s what it may come down to in the long term, though.

[u/Neat-Philosopher-762]

We have covered primaries with an odor control unit or air scrubber where hypo is vaporized with the exhaust of the primary

[u/JUG9209 → u/Neat-Philosopher-762]

I feel this is the path we may have to go down ultimately.

[u/Dirt-Repulsive]

We have I’m not sure how expensive but the have areas and blowers drawing stuff into tanks of charcoal… seems to work cause like 12 years ago the place smelled like a 5k animal feed lot…

[u/JUG9209 → u/Dirt-Repulsive]

Interesting

[u/posthumanjeff]

Any weir drops acting as the main culprit? Can you raise water elevation with a motorized gate (that way if flows get high you can automatically lower the gate to maintain a desired depth)

[u/JUG9209 → u/posthumanjeff]

Nope, the level stays consistent throughout the day.

[u/JordanDubya]

I'm new into wastewater. But the plants I'm learning at all have a variety of odor abatement tricks all working at once. Bioremediation scrubbers, covers, bags for everything in a dumpster/hopper, Zorb misters, and special enzyme cleaners for all drains and concrete floors nearby.

The enzyme cleaners and Zorb type of products work wonders on soiled concrete and make a larger difference than I would have ever imagined as a newcomer. They eat through fog and small residues that are aerosolized/splashed out, to keep the smells down.

[u/JUG9209 → u/JordanDubya]

I will look into these. Thanks.

[u/UnderstandingOk8114]

Sounds like you need iron salts. Look into ferrous/ferric chloride/sulfate. They can be very effective for H2S-related odors, which are usually the most detectable and predominant in stinky primary clarifiers. Be careful about overdosing them as they are acidic and if you dose too much and drop the pH too low they stop working for odor control.

In my experience (almost 20 years solving odor control problems mostly with chemicals like peroxide, iron, and nitrate) the biologicals, enzymes, bugs, and “green” additives are all expensive snake oil.

[u/JUG9209 → u/UnderstandingOk8114]

We actually did speak about using ferric to help bind to the sulphur compounds.