100 KLD Sewage Treatment Plant – SBR Technology
SBR treats sewage in time-sequenced batch cycles. A single SBR tank performs aeration, settling and decant in cycles—saving footprint (no separate clarifier) and offering flexible control for varying loads. This 100 KLD SBR design is indicative; final details after site visit & jar test.
Process Flow (SBR) — Sequence
SBR eliminates separate secondary clarifier. Decant can be gravity-based or via floating decanter; RAS is internal to cycle. Excess sludge pumped to sludge holding for dewatering.
Cycle Timing & Reactor Volume (Example for 20 h/day)
For 20 hours/day operation, we divide treatment into repeated cycles. Example cycle split (configurable):
| Cycle Phase | Time (hrs) | Notes |
|---|---|---|
| Fill | 2 | Influent enters SBR reactor; can be continuous or intermittent filling |
| React (Aeration) | 10 | Aeration with fine bubble diffusers; biological oxidation |
| Settle | 6 | Quiescent period for sludge settling |
| Decant | 2 | Remove supernatant (gravity or floating decanter) |
| Total cycle | 20 hrs | One full cycle per day; repeat according to flow schedule |
Reactor Volume Calculation (digit-by-digit)
SBR reactor must accommodate batch volume equivalent to hourly inflow × (Fill + React + Settle + Decant fractions). Using the example cycle (20 h total), the batch volume equals hourly flow × cycle duration for continuous feed consideration.
Approximate SBR Reactor Volume: We select a practical working volume ≈ 30,000 L (30 m³) — this provides equivalent HRT similar to ASP designs (6 hr effective biological time) while allowing batch sequencing. Use multiple SBR reactors (2 × 15 m³) for operational flexibility if required.
Design Basis & Key Parameters (100 KLD)
| Parameter | Value / Assumption |
|---|---|
| Design daily flow (Qd) | 100,000 L/day (100 KLD) |
| Operating hours | 20 hours/day |
| Design hourly flow (Qh) | 100,000 / 20 = 5,000 L/hr |
| Influent BOD (assumed) | ~300 mg/L |
| Target effluent | BOD < 30 mg/L (after polishing) |
| Typical MLSS (SBR) | 2000–4500 mg/L (site dependent) |
| SVI target | 80–150 mL/g |
Decanter & Decanting
Decant options:
- Floating V-notch decanter (PP/FRP): Preferred for gentle, controlled decant; simple maintenance.
- Static decanter / weir: Simpler but less controllable.
Default chosen: Floating PP decanter with V-notch (as requested).
Aeration, Blower & Power Estimates
Design air ≈ 1,300 m³/day ≈ 65 m³/hr → Recommend blower(s) 70–100 m³/hr (2 units for redundancy).
During react phase, blower runtime concentrated; ensure blowers & piping sized for peak oxygen demand during react hours. For SBR, blowers must be controlled to run during React phase only (PLC timer).
Polishing, Disinfection & UF Option
After decant, clarified supernatant goes to polishing train:
- Pressure Sand Filter (PSF) → Activated Carbon Filter (ACF)
- Online Hypochlorite Dosing (automatic dosing pump)
- Optional UV disinfection for additional pathogen control
- If reclaimed water required for sensitive reuse (RO feed or cooling tower), include UF/RO in polishing train
Expected Performance
| Parameter | Influent (Design) | Expected Treated (After Polishing) |
|---|---|---|
| pH | 6.5 – 7.5 | 6.5 – 7.5 |
| BOD | ~300 mg/L | < 30 mg/L |
| COD | ~900 mg/L | < 200 mg/L (site dependent) |
| TSS | ~150 mg/L | < 30 mg/L |
| Oil & Grease | ~50 mg/L | < 5 mg/L |
Use treated water for gardening, toilet flushing, vehicle wash. For RO feed/cooling towers, include UF/RO & verify with lab.
Operation & Maintenance (Key points)
- Set and monitor SBR cycle times by PLC. Adjust Fill/React/Settle based on load.
- Maintain DO during React (2.0–3.5 mg/L).
- Monitor MLSS & SVI weekly—adjust wasting accordingly.
- Inspect decanter periodically; keep V-notch clean to avoid carryover.
- Schedule blower maintenance & diffuser cleaning.
- Maintain logs for TNPCB/CPCB compliance.
Get Quick Quotation / Technical Proposal
Free site visit & jar test for final design & price. Send photos, sample report and brief.
Sales / Technical: +91 97100 35249 • Service: +91 99623 95875 • Email: rrrenviro@gmail.com