Wastewater lagoons
Sludge occupying eight to ten feet of an eleven-foot lagoon, leaving nine per cent of the design capacity available for treatment, against a $600,000 dredging quotation.
reduction in sludge depth in the treated area
01The plant
A 2.5 hectare (6 acre) municipal lagoon, 3.4 m (11 ft) deep, aerated by two floating mixers at the front end.
02Before
Years of accumulation had left 2.4 to 3.0 m (8 to 10 ft) of material through the lagoon, leaving very little working depth. A dredging quotation stood at $600,000.
03Treatment
A dense sinking solid applied to an area of the lagoon carrying significant accumulation, over six months.
Every result in this library was measured at an operating plant treating with one of the formulations SediLogic supplies, over the window stated above. It is a field result published as reported, not a controlled trial we ran.
04Sizing
Applied to a defined treated area rather than across the whole lagoon, which is what made the comparison below possible.
05Method
Accumulation measured monthly for six months in the treated area and in an untreated area of the same lagoon, and compared.
06Comparison
An untreated control area was held in the same lagoon and measured on the same schedule. Same water, same weather, same loading — which removes the seasonal question that hangs over most records here, and is why a 28 per cent result is worth more than several larger ones.
07Outcome
The dredging project was postponed with no reported effect on effluent quality.
At the start
8 to 10 ft of accumulation, treatment capacity down to about 9 per cent in the treated area.
At the close
28 per cent less accumulation in the treated area, and capacity there up from 9 to 35 per cent.
08Limits
The control area is described but its own readings are not published, so the comparison has to be taken on trust. Neither area's volatile fraction is given. Postponed is not avoided — the inert fraction is still there.
Only the volatile organic fraction of a sludge responds to any of this. Grit, sand, silt, mineral precipitates and plastics remain at any dose, here and everywhere else.
—What we would supply
This is the duty SediLogic supplies and sizes. Which article depends on where the material sits: Sedivore Spike is the denser solid and carries down through depth to an established blanket, Sedivore Puck is a smaller unit that spreads a calculated dose across the bed, and SediLogic Maintain is a soluble pouch for load carried in the water column — with Sedivore Polar for that same duty where the water runs cold enough to stall a standard blend.
A quantity for your own lagoon comes from the dosing planner, sized against your dimensions and loading from the manufacturer's written dose method. It does not come from the figure on this page, which was set for a lagoon that is not yours.
—Read next
Wastewater lagoons
Municipal24 weeks
of accumulated solids digested
Just over five feet of accumulated solids in the primary aerated lagoon, assessed at 2,365 dry tons. The plant wanted a route that did not involve dredging.
Wastewater lagoons
MunicipalFive months, May to October
reduction in solids volume overall
Accumulated solids across two lagoon cells, against a specification calling for a 50 per cent reduction. The treatment window was bounded by water temperature, which has to stay above roughly 55°F for the organisms to work at all.
Wastewater lagoons
Municipal3 months
of organic solids digested
Decades of loading had taken the lagoon to a measured 20.5 per cent solids, with a dredging quotation in hand and no budget line to meet it.
Your lagoon next
A different plant, a different loading and a different sludge. What decides your result is how much of your own accumulation is organic and treatable, and whether the dose is sized against the lagoon in front of us rather than read off this page. Tell us the dimensions and we will size it.
