Nothing here is secret, and most of it is not ours.
This page is what the verification record checks. Read them in order: here is what the tool computes and where each method comes from; then, on the next page, here is what happened when we read our own code against the books.
| What | Where it comes from |
|---|---|
| ASM3 kinetics and stoichiometry | IWA Scientific and Technical Report No. 9 |
| Clarifier, screen, filter and anaerobic sizing | Wastewater Engineering: Treatment and Resource Recovery, Metcalf & Eddy, 5th ed., cited by equation number on the block that uses it |
| Solution–diffusion membrane transport | Metcalf & Eddy 5th ed., Eqs. 11-38 and 11-39 |
| Reverse-osmosis array: polarisation, derated flux, spacer pressure drop | Saeed & Alhawaj (2024), Water Practice & Technology 19(7):2681, Eqs. (7), (14), (17) and (18) |
| Clarifier settling curve from SVI | Metcalf & Eddy 5th ed., Eq. (8-86), p. 896 — the Daigger (1995) correlation |
| Ultrafiltration | Hydranautics HYDRAcap MAX technical and pilot manuals |
| Element-by-element march, polarisation factor, temperature correction | Standard membrane projection practice, in every major manufacturer's manual — not textbook material, and the block says so |
| Fenton oxidation | No textbook design method exists. The block's own reference sheet says so. |
ASM3, thirteen components and twelve processes, solved as steady-state continuously stirred reactors.
It is derived at run time from COD, nitrogen and charge conservation, which is why the mass balances close exactly rather than approximately. A model whose balances close because the coefficients were fitted can be quietly wrong in a way one whose balances close by construction cannot.
Vmax and k are derived from Metcalf & Eddy Eq. (8-86), the Daigger (1995) correlation, rather than entered by hand: Vmax = 6.495 m/h, fixed, and k = 1000(0.165 + 0.00159·SVI). The correlation exists so that a flux analysis can be performed from SVI data in place of an extensive settling-test procedure, and SVI is the quantity actually measured at a working plant.
A measured settling-column result may be entered instead and takes precedence. Both values are entered or neither, and the route taken is reported. The derived pair does not reproduce the values the reference quotes under Eq. (8-85); the difference, and its effect on an existing flowsheet, is recorded in the verification.
Item P, third passNot over one reactor, and it counts only solids that actually cross a system boundary — solids going round the return loop have not left the system. The aerobic fraction is reported separately, because nitrifier washout is governed by aerobic sludge age and not by the total. A plant that loses nitrification while its nameplate sludge age appears comfortable is the case that distinction explains.
The entered TKN scales the composition factors on the substrate fractions, so that the organic nitrogen sums to TKN less ammonium. This is not how it worked originally and the story is on the verification page — it is the single most consequential thing the check found.
A design check reports when that scaling has moved substantially from the municipal default. Where it has, the nitrogen analysis and the COD fractionation are describing different water.
What the check foundNot a lumped array with a rejection percentage: each element in the pressure vessel is solved in sequence, with solution–diffusion transport, film-theory concentration polarisation, and the pressure drop through the spacer following the flow through that element rather than a flat allowance.
Sodium, potassium, calcium, magnesium, strontium, barium, chloride, sulfate, bicarbonate, nitrate, fluoride, phosphate, silica and boron — each with its own salt permeability relative to sodium chloride. Divalents are held back far better than monovalents; boron and carbon dioxide slip through. That is why the answer depends on the feed ion analysis, and why an ion analysis carrying a charge imbalance raises a warning rather than returning a silent result.
Each element's A and B are back-calculated from its own published test point, so the numbers stay self-consistent with the datasheet they came from rather than drifting away from it.
With its Langelier index and its scaling potential, because the practical question on a reuse scheme is usually not the permeate.
Standard oxygen transfer rate to actual, at the entered alpha factor, standard oxygen transfer efficiency, diffuser submergence and diffuser fouling factor — the four inputs the aerobic block requires and applies. Dissolved-oxygen saturation follows the Benson–Krause relation, which reproduces the reference appendix's table to ±0.001 mg/L across 0–40 °C — it did not, once, and that is on the verification page.
Two site conditions carry into both. Site elevation fixes the barometric pressure from the ISO 2533 standard atmosphere, and the pressure factor Ω, which is P_b/P_s, multiplies the driving force in Eq. (5-70): at 2,240 m the pressure is 77.15 kPa against 101.325 at sea level, Ω is 0.7615, and the oxygen transfer duty rises by a factor of 1.423 — about 79% more aeration energy. Ambient air temperature sets the density of the air the blowers draw, from Appendix B-3. It is used at the blower inlet and the model adds no blower-house rise, so a designer who wants that allowance enters it in the field.
The blower computes shaft power, pressure ratio, air mass flow and specific power at those conditions, and reports air flow twice, normal and actual at the inlet: a 500 Nm³/h duty is 679 actual m³/h at 2,240 m and 30 °C. It compares its duty against the process air the reactors downstream actually call for. If those two disagree, a check says so. That block ignored its own inputs until the verification found it.
More than fifty, at three levels: errors, meaning the design cannot be correct; warnings, meaning it falls outside a published range; and reported figures, which are neither but warrant attention — a sludge age, a blower duty.
Each check compares the design against a range taken from the references, and each states which range and its source. A check that fires without identifying its comparison basis is an opinion.
Two are recorded here because they were wrong and are now correct. A screenings-volume range measured on municipal sewage fired on every industrial design; it is now scaled to the feed's own solids. A flux-spread check fired on essentially every standard membrane layout, because flux tapers by design. It now fires when the rear of the train has ceased to contribute, which is the useful criterion.
Return activated sludge and internal nitrate recycle are ordinary connections. The solver identifies and tears the loops without configuration.
A flowsheet is solved in the browser tab, never on a server: a solve completes in milliseconds rather than a network round trip. The project itself is stored on KinetiRO's server, under the account, encrypted so that KinetiRO cannot read the design unless the user shares it; the storage section of the product page states what that means.
A stale figure that still appears current is worse than no figure.
Steady state, not dynamic. No cost estimating. No civil, structural or electrical design. Equalization is a pass-through at steady state. Fenton has no book method. Manufacturer element data is indicative and must be confirmed against the current datasheet and the manufacturer's own projection software before a design is issued. The full list, with the reasoning, is on the product page.
An account is required. During the beta every account gets full access, and no card is asked for.
