Detlef,

I don't know but as you said mechanical action of cascading effluent over media should volatilize dissolved gases.

This is an issue for odour control in WWTP. We try to reduce turbulence to prevent odour release and causing a public nuisance. However under controlled conditions and if you were collecting gas from the top of the column this could be a good idea.

Regards
Seamus.

Dear Colleagues,

I am thinking to try out a kind of "enclosed stripping cascade" after the AD-effluent filter (party-filter) of an ABR and having a permanent -0,5 - 0,8 bar (negative pressure) to recover dissolved methane. All my possible undertakings in this regard have an "Open Source" tag on it. All results and necessary mistakes will be shown to you.

I found little via Internet on "recover dissolved methane" from AD-effluent.
- pubs.acs.org/doi/full/10.1021/es405553j "Dissolved Methane: A Hurdle for Anaerobic Treatment of Municipal Wastewater"

"...some technical approaches for recovery of dissolved methane from treated effluent have been proposed, for example, membrane separation, air stripping etc., their feasibility has not yet been fully evaluated in terms of economic viability and process safety. Without proper technical solutions, dissolved methane would be a technical hurdle for broad application of anaerobic processes for treatment of municipal wastewater that contains only low organic constituents."

- www.researchgate.net/publication/2501765...t_by_Closed_DHS_Unit
"closed DHS reactor"

For the rough worldwide condition, I guess it is better not to go for stripping via membrane. Therefore and for simplicity reasons an "enclosed cascade with negative pressure" might be one option!?

First stage scale 1:10: using of the shelf a 400 mm PE-pipe having exchangeable cascades inside to create an "enclosed stripping reactor" (cheap to make: 200EUR)
Second stage real scale: using as an enclosed reactor off the shelf a modified very small domestic bio-film wwtp "Clearfox nature" made out of PE, see link, which have inside already a cascade made of loos plastic fabrics www.abwasserbehandlungsanlagen.de/Clearf...ure_Grafik_klein.jpg (2.500 EUR)

My question to you is, would it be necessary to have like the DHS a permanent air supply to this enclosed reactor to strip Methane out of the effluent? Could it be already enough, just to "beat" the effluent via cascade and exposing effluent simultaneously to a negative pressure?

Looking forward to your replies

All the Best
Detlef SCHWAGER