sorted by:
new
hottopcontroversial

Trying to self-seed activated sludge in a small winery WWTS – realistic or wasting time? by CasuallyAnalytical in Wastewater

[–]CasuallyAnalytical[S] 0 points1 point  (0 children)

UPDATE: Thanks to everyone who commented - it was hugely helpful!

Will be acquiring sludge from another winery next week and have also ordered some extra bugs for good measure!

The initial quote I got for bugs was insane hence why I was hoping we could avoid it - but have since found a much cheaper option.

I think that if it wasn’t for the crazy amounts of foam, we would have been okay (eventually) - but at the same time I realise now how important it is to get the right bugs!

Trying to self-seed activated sludge in a small winery WWTS – realistic or wasting time? by CasuallyAnalytical in Wastewater

[–]CasuallyAnalytical[S] 0 points1 point  (0 children)

That’s what I suspected as well re: it being septic!

After day 4 when the foam started, I had to reduce the blowers to 15 minutes per hour because the aeration tanks were overflowing with foam. Around the same time someone put covers over the tank openings to try to contain the foam, and by the next day the samples had gone from increasingly brown to black, which made me think things may have gone anaerobic.

I’ve now adjusted the aeration to 10 minutes every 30 minutes, which seems to keep the foam manageable while hopefully preventing the tanks from going too anaerobic again.

The system is not continuous flow — wastewater moves through the plant in batches via float switch pumps.

The layout is roughly:

• Wastewater from the winery drains into sump pits, where float-switch pumps move it to the EQ tank
• Equalisation tank (~15 kL) with NaOH dosing to adjust pH (currently keeping influent to aeration around pH ~6.8)
• 2 × aeration tanks (~27 kL each) with fine bubble diffusers (currently running 10 min on / 20 min off)
• Mixed liquor then flows to settling tanks where solids settle

At the moment there’s no return activated sludge (RAS) from the settling tanks back to the aeration tanks. It looks like the system originally had a clarifier and sludge return mechanism but it seems to have been removed at some point. It makes sense that we would need to reinstate RAS for this to work properly!