Aeration basins
Nine months of filamentous growth had taken the settled-volume test above 980 ml/L, so the clarifier could not hold solids and the plant was paying to haul them away.
reported annual saving once settling recovered
01The plant
A dairy processing plant running 1.9 MGD (7,192 m³/day) at about 500 mg/L influent biochemical oxygen demand.
02Before
A change in production pushed fats and grease up and the sludge stopped settling — the settled volume after thirty minutes sat above 980 mL/L for more than nine months. Meeting the suspended-solids permit meant heavy chemical coagulant dosing at the clarifier and constant operator attention. Chlorination had been tried and failed; neutralising influent pH gave only slight improvement.
03Treatment
Once filamentous bulking was identified as the cause rather than a symptom, a programme was run using a grease-targeted formulation.
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.
04Method
Settled volume after thirty minutes, tracked against the nine-month baseline that preceded treatment.
05Outcome
About $40,000 a year saved, and the plant able to take a waste stream it previously could not.
At the start
Settled volume above 980 mL/L for over nine months, coagulant dosed continuously to hold the permit.
At the close
Settling recovered, coagulant, disposal and labour costs down, and enough treatment capacity freed to bring a high-strength waste stream into the plant.
06Limits
The closing settled-volume figure is not published, so the recovery is described rather than quantified. The saving is the plant's own accounting and its basis is not shown. Nothing was left untreated, and a plant emerging from nine bad months would be expected to improve somewhat on its own.
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
SediLogic Liquid is the article in the range that reaches this — a concentrate for systems that take a metered or poured dose rather than a solid one, which is what a basin under continuous flow is. Nothing in the dry range is the right vehicle for mixed liquor: a sinking solid is built to leave the water column, and mixed liquor is the water column.
SediLogic holds a written dose table for wastewater lagoons and for no other duty, so the planner will not size a basin. A quantity for one is settled with a person against your flow and your loading.
—Read next
Aeration basins
Industrial60 days
to clear the foam blanket
A stable foam blanket on the aeration basin, fed by grease in the incoming load and unaffected by the usual mechanical answers.
Aeration basins
IndustrialOne month from a January application
lower effluent BOD within a month of dosing
A million gallons a day of mill effluent, and a BOD figure that climbed every winter as the water cooled and biological activity fell away with it.
Aeration basins
Municipal1 year
reduction in secondary sludge production
A food-processing load arriving at a municipal works, bringing enough grease with it to drive filamentous growth and cost the plant its settling.
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.
