ROI Calculator · Wastewater

Aeration is the bill.
Is our oxygen actually cheaper?

Most vendor calculators take your aeration spend and apply a transfer-efficiency gain to it. That answers the wrong question. This one costs both sides in kilowatt-hours per kilogram of oxygen actually transferred — your blowers after alpha, fouling, temperature and dissolved-oxygen deficit, against our concentrators plus the circulation pump that carries the oxygen into the basin. Sometimes the answer is that your aeration is already efficient and we cannot beat it. The page says so.

Live — nothing to submit Both sides costed per kg O₂ Will return a negative answer Indicative pricing
01

The plant and its load

Oxygen demand is what sizes everything here, and oxygen demand comes from the load, not from the flow. On a nitrifying plant the nitrogen term is often larger than the carbonaceous one, which surprises people who size on BOD alone.

MGD
°C
mg/L
mg/L
mg/L
mg/L
of nitrified
$/yr
BOD removed
Nitrogen nitrified
Carbonaceous oxygen demand
Nitrogenous oxygen demand
Denitrification credit
Total oxygen demand
02

What you spend today

Every benefit on this page is a cost you already carry, reduced. Nothing here is sold, so there is no revenue line and no margin to credit against — which is why the reality check at the bottom is stated against your own operating budget instead.

kg TSS/kg BOD
%
$/wet t
$/yr
$/yr
lb/d
$/lb
lb/d
$/lb
Sludge hauled
Annual haulage cost
Annual surcharge exposure
03

How efficient is your aeration now?

This is the panel the whole page turns on. A diffuser grid is rated in clean water at 20 °C with zero dissolved oxygen; a working basin is none of those things. Applying the nameplate figure to real process water overstates the incumbent by a factor of three or more — which would make our comparison look far better than it deserves.

mg/L
kg/kg
×
Clean-water saturation at your temperature
Your aeration, standard rating
Your aeration, field derated
Your cost per kg O₂ delivered
Our cost per kg O₂ delivered
Difference
04

The oxygen system, and what it costs

The side stream is derived, never entered: water carries only so much dissolved oxygen per pass, so the flow follows from the oxygen duty and the transfer per pass. This is also where the energy case is won or lost — at 40 mg/L added you move 25 m³ of water per kilogram of oxygen delivered; at 20 mg/L you move fifty, and the pump doubles.

%
mg/L
psi
m
$/kWh
Oxygen supplied
Side-stream flow
Injector
Oxygen plant
Plant draw
Circulation pump
$
$
% of equipment

Equipment
Installation
Indicative installed cost
Service & consumables
Annual operating cost
05

Value levers

Every lever except the energy one is scaled by the share of oxygen demand we actually supply — you cannot claim an effect on water you never treated. The energy lever has no slider on purpose: a slider there would let you assume the very thing this page exists to test.

Gross annual benefit
Service
Net annual benefit
06

Sensitivity

What actually moves the answer, and by how much. Each assumption is swung across its evidence band, not the full slider range.

years
%
% of steady state

What moves the answer

Payback across supplied share and power price

What has to be true
07

Take it with you

A one-page analysis you can print, save as PDF, or put in front of a works manager, a finance committee or a board — with the assumptions, the oxygen basis, the provenance of every figure and the pricing caveat attached.

Generate the report

The numbers on this page are already yours — no gate on those. This just puts them into a document and lets us follow up with a real quotation if you want one.

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