Wastewater Stream Foam Removal

I'm reasonably new in the industry also, but the first step is usually to understand exactly what the foaming material is.

I'd be very reluctant to just throw other chemicals at it without that first understanding. you could end up with a coctail that needs other processes before being suitable for discharge.

If its teh saem GE that I've dealt with in the past, they are expensive, but good value. Whatever they suggest, get them to explain the chemistry involved, the control mechanisms that will be used and how they respond to different contamination levels in the inflow material. Learn and understand the process with them.

Also, if it's a single point source, maybe feedback to them will help them reduce their use of the foaming agent (reduce costs) and at teh same time reduce your treatment challenge.

My thoughts though tend towards something that will cause the foam to modify to an oil/fat type of consistency that would float and then use a "grease arrester" arrangement to capture that material. [Grease arrester is a large tank where the water cools to a lower ambient condition and has low flow velocity, allowing the fats and such to collect at the surface while the general water can flow away from a sub-surface point.]

How much volume are you treating? (Peak flow rate and volume per day.) This will give you some means to describe the device you need. Resturuants and large cooking shops would already be familiar with this set-up.

Try using a misting spray. It won't use a lot of water or energy, but a constant rain of little drops will probably break the foam bubbles.

Now whatever was in the foam will be on top of your effluent. Don't agitate it, or you will get more bubbles.

Since foam floats you can also skim it off the surface.

*Just pass the water thro' inner well arrangement having higher wall height above the clarifier top level. Now what will happen is all the foam will get arrested and stay at the inner well surface and all the falling foam will rise and stay confined into the inner well, which can be periodically cleaned like once in a week.

* The option is to reduce your mixer RPM levels to minimize foam

* Silicon based Defoamer dosing as a diluted solution along with infeed water should de foam on a contonuous basis.

Another simplest thing is to tie fabric filter bag thro the mouth of the water delivery pipe above the water surface so the all foam will be cracked away.

Pass thw water thro' pebbles or sand layer by trickling , a no cost cheap alternate mechanical defoamer.

Problems and solutions just co exist, just think on the causes and solve with simple improvisations

Await your feed back

Phosphates in soaps had been replaced with NTA (nitrilotriacetic acid) so I would think phosphates are not the problem but unless you analyse the sewage waste don't rule phosphates out. One method of removing P from the water is to use iron salts to precipitate the P. Sometimes you can see a lot of foaming below a small waterfall in the autumn. This natural foaming is caused by the release of phosphorous in leaves. I have investigated many such false pollution allegations.

When NTA is present the iron may chelate with the iron and prevent precipitation. One way of controlling such problems is to increase the sludge retention times. If your volumes are excessive then you may need to add sludge retention or increase sludge retention times. I am not a specialist in sewage treatment but am aware of them in water treatment. Sample the water for NTA and methyl blue activated substances (MBAS).