Enter tank volume, flow, COD and sludge concentration — get first and maintenance dosing, loading verdicts, nutrient and aeration sizing, and a cultivation timeline in seconds. Five formula groups cover the whole decision chain from first dose to acceptance.
The formulas are standard activated-sludge engineering; the dosing ranges follow our published technical practice. Results are engineering estimates — final dosing must be based on measured site data.
1 · First dose & cell-concentration check
Split the first dose over 3–5 additions within 1–2 weeks. Dry powder added directly revives poorly (<10%); activate first in 30–40 °C water with molasses and urea under aeration for 4–6 h. After stabilisation, 10%–20% of the first dose per month maintains dominance.
2 · Loading check: Nv & F/M
Normal ranges: Nv 0.5–1.5 kgCOD/(m³·d); F/M 0.1–0.3 kgCOD/(kgMLSS·d). A passing Nv with an excessive F/M means "enough tank, not enough sludge" — throttle the inflow or add seed sludge rather than more culture.
3 · Nutrient dosing (BOD:N:P = 100:5:1)
Urea counted at 46% N, potassium dihydrogen phosphate at 22.7% P. Dose continuously with the inflow; dissolve urea and phosphate separately. During low-flow start-up scale nutrients down with the actual flow.
4 · Oxygen demand & blower capacity
Oxygen demand peaks 2–4 days after dosing. Keep DO at 2–4 mg/L; below 1.5, cut the inflow immediately. Fouled diffusers can halve real transfer — verify by measurement, not nameplate.
5 · Cultivation timeline (MLSS growth)
Y = 0.5, Kd = 0.06. For poorly biodegradable wastewater (BOD/COD 0.3–0.4, e.g. cellulosic streams) growth is discounted — take the upper timeline and prioritise extra seed sludge: cultures supply function, they do not replace biomass. Advance loading steps only when SVI < 150 mL/g and SV30 < 35%.
6 · Product selection by duty
| Duty | Recommended product |
|---|---|
| General municipal / organic wastewater (aerobic) | Wastewater Treatment Bacteria Culture JY-MS-01 |
| High-organic food / slaughterhouse / livestock wastewater (aerobic) | Wastewater Treatment Bacteria Culture JY-P001 |
| Anaerobic stage: odour control & biogas yield | Wastewater Treatment Bacteria Culture JY-AO1-01 |
| Anaerobic stage: COD polishing & biogas | Wastewater Treatment Bacteria Culture JY-AO2-02 |
| Anoxic / denitrification & mixed duty | Wastewater Treatment Bacteria Culture JY-C001 |
| Petrochemical / oilfield wastewater & oily sludge | Wastewater Treatment Bacteria Culture JY-MO-01 |
Frequently asked questions
Is more inoculant always better?
No. Overdosing rapidly consumes local dissolved oxygen and can turn the tank anaerobic, suppressing the very culture you added. Dose by load calculation and split the additions, aiming at stable effluent rather than a bigger number.
Can bioaugmentation be combined with disinfectants?
No. Bleaching powder and quaternary ammonium disinfectants kill microorganisms directly. Keep dosing points and timing well separated from any disinfectant, or the culture will not establish.
How soon will water quality improve?
It depends on system size and initial condition. Improvement typically appears progressively within 1–3 weeks of split dosing; dissolved-oxygen and COD monitoring give earlier signals.
Should the dose be increased in cold weather?
Low temperature slows microbial metabolism. A modestly higher dose and a longer acclimation period are prudent, while keeping sufficient dissolved oxygen to avoid a combined cold-low-DO inhibition.
When is a top-up dose needed?
When effluent COD or ammonia trends back up, settleability deteriorates or odour returns, the working population is losing capacity — combine a load-based top-up with follow-up testing.
The calculator is the start, not the answer
Send us your influent COD, ammonia, tank volume and the problem you are facing. Our engineers will return a staged dosing plan — moisture-content checks, activation procedure and a step-loading schedule — based on your water analysis, not a guess.