Wastewater lagoons
Solids had built to near the surface across a nine-foot section, short-circuiting flow through the lagoon and putting a dredging quotation on the table.
solids reduction in the treated section
01The plant
A 238 million gallon lagoon at a large pulp and paper mill, 43.5 per cent full of accumulated solids before treatment.
02Before
Accumulation had reached close to the surface in a nine-foot section, short-circuiting flow across the lagoon and costing treatment capacity. The cause was unsettled solids and high organic load arriving from the secondary clarifier, with poor facultative digestion on the bottom.
03Treatment
A single treatment, diluted in a 55-gallon drum and poured in by pail along the west bank of the affected section — a treated area of about 384,250 square feet. One application, then ninety days.
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
Against the treated area rather than against the whole lagoon — one section of a 238 million gallon impoundment was dosed, not the impoundment. A quantity set for a section is not a rate for a lagoon of any size, so the quantity is not carried here.
05Method
Core samples at four locations, before and ninety days after, analysed by an outside laboratory for blanket depth, total solids and volatile fraction.
06Outcome
A 6:1 return reported against the dredging quotation. This is the strongest record in the library on method — cores at fixed points, both ends, outside laboratory, and the volatile fraction actually stated.
At the start
1,450 dry tons in the measured strata, 43 per cent of it organic, with solids nearly reaching the surface in a nine-foot section.
At the close
160 dry tons remaining in the same strata, the blanket down 8.4 inches, and roughly 9,900 cubic yards of hydraulic space recovered.
07Limits
89 per cent describes the monitored strata, not the whole 238 million gallon lagoon, and the two are easy to confuse. Nothing was left untreated. Four cores is a thin sample for a lagoon this size, and the record does not say how the four locations were chosen.
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.
