RRR
200 KLD Sewage Treatment Plant – SBR Technology
Sequencing Batch Reactor (Fill → React → Settle → Decant) — flexible, compact and ideal for variable loads. Designed for 20 hours/day operation.
Overview
The Sequencing Batch Reactor (SBR) treats sewage in time-sequenced batch cycles inside the same reactor — performing fill, react (aeration), settle and decant in cycles. SBR is excellent where footprint control, variable loading and operational flexibility are needed. This 200 KLD design is indicative and will be finalized after site visit & jar test.
Where Sewage is Generated (Typical Applications)
- Residential Apartments & Gated Communities
- Commercial Complexes & IT Parks
- Schools, Colleges & Hostels
- Hospitals & Healthcare Facilities
- Hotels, Restaurants & Food Courts
- Small to medium industrial estates (non-heavy industrial streams)
Process Flow (SBR) — Sequence
Toilets & Wastewater → Bar Screen → Oil & Grit Trap → Collection / Equalization Tank (disc diffusers) → Raw Sewage Transfer Pump → SBR Reactor (Batch cycles: Fill → React → Settle → Decant) → Polishing: PSF → ACF → Hypo / UV → Final Treated Water Tank → Reuse (gardening, flushing, vehicle wash).
SBR replaces separate clarifier; decant is by floating decanter (V-notch) or controlled weir. Excess sludge is wasted to sludge holding and dewatered.
Cycle Timing & Reactor Volume (Example for 20 hrs/day)
Design daily flow = 200,000 L/day (200 KLD). Operating hours = 20 hrs/day. Hourly flow (Qh) = 200,000 / 20 = 10,000 L/hr.
| Cycle Phase | Time (hrs) | Notes |
|---|---|---|
| Fill | 2 | Influent enters reactor (intermittent or continuous fill) |
| React (Aeration) | 10 | Biological oxidation phase |
| Settle | 6 | Quiescent settling period |
| Decant | 2 | Supernatant removal via floating decanter |
| Total per cycle | 20 hrs | One full cycle per 20 hours; cycles repeat based on operation schedule |
Reactor Volume (Indicative)
For continuous-equivalent sizing we choose a **working reactor volume ≈ 60,000 L (60 m³)** — this gives a biological HRT comparable to ASP designs and handles the batch flow for one cycle. Optionally use 2 × 30 m³ reactors for operational flexibility (one on duty, one on standby / maintenance).
Design Basis & Calculations — step-by-step
Given / Assumed:
Daily flow Qd = 200,000 L/day • Operating hours = 20 hr/day • Qh = 10,000 L/hr
Influent BOD (assumed) = 300 mg/L • Target removal ≈ 80% (polished <30 mg/L).
Daily flow Qd = 200,000 L/day • Operating hours = 20 hr/day • Qh = 10,000 L/hr
Influent BOD (assumed) = 300 mg/L • Target removal ≈ 80% (polished <30 mg/L).
1) BOD mass/day
Influent BOD = 300 mg/L = 0.300 g/L.
BOD mass/day = 200,000 L × 300 mg/L = 60,000,000 mg = 60,000 g = 60.000 kg/day.
2) BOD removed (80%)
Removed BOD = 60.000 kg/day × 0.80 = 48.000 kg/day.
3) Oxygen demand (1.5 kg O₂ per kg BOD removed)
O₂ required = 48.000 kg/day × 1.5 = 72.000 kg O₂/day.
4) Air required (0.278 kg O₂ per m³ air at 100% and 10% transfer used)
Effective O₂ per m³ with 10% transfer = 0.278 × 0.10 = 0.0278 kg O₂/m³.
Air (m³/day) = 72.000 / 0.0278 ≈ 2,590.65 m³/day.
Air (m³/hr) = 2,590.65 / 20 = 129.53 m³/hr.
Recommendation: Provide blowers totalling ~ 150–200 m³/hr (2 units duty + standby) to allow margin for aeration, any media mixing (if hybrid), and head losses.
Influent BOD = 300 mg/L = 0.300 g/L.
BOD mass/day = 200,000 L × 300 mg/L = 60,000,000 mg = 60,000 g = 60.000 kg/day.
2) BOD removed (80%)
Removed BOD = 60.000 kg/day × 0.80 = 48.000 kg/day.
3) Oxygen demand (1.5 kg O₂ per kg BOD removed)
O₂ required = 48.000 kg/day × 1.5 = 72.000 kg O₂/day.
4) Air required (0.278 kg O₂ per m³ air at 100% and 10% transfer used)
Effective O₂ per m³ with 10% transfer = 0.278 × 0.10 = 0.0278 kg O₂/m³.
Air (m³/day) = 72.000 / 0.0278 ≈ 2,590.65 m³/day.
Air (m³/hr) = 2,590.65 / 20 = 129.53 m³/hr.
Recommendation: Provide blowers totalling ~ 150–200 m³/hr (2 units duty + standby) to allow margin for aeration, any media mixing (if hybrid), and head losses.
Tank Sizing (Indicative)
| Unit | HRT / Note | Calculated Volume (L) | Rounded (m³) |
|---|---|---|---|
| Collection / Equalization Tank | 6 hours | 10,000 × 6 = 60,000 L | 60 m³ |
| Bar screen & O&G | 0.5 – 1 hr | ~10,000 L | 10 m³ |
| SBR Reactor (working volume) | Batch reactor (one cycle) | ~60,000 L | 60 m³ |
| Polishing / Clarified Buffer | Buffer | ~3,000 – 5,000 L | 3 – 5 m³ |
| Final Treated Water Tank | Reuse buffer | ~10,000 L | 10 m³ |
| Sludge holding | Intermediate | ~2,000 – 4,000 L | 2 – 4 m³ |
Using 2 reactors of 30 m³ each is a common approach for redundancy and easier maintenance. Reactor sizing and number depends on site operation preferences.
Aeration, Blower & Decanter
Blower: Blowers sized for peak oxygen demand during React phase; recommended combined capacity ~ 150–200 m³/hr split across two units (duty + standby).
Decanter: Floating PP V-notch decanter recommended for controlled decant. Alternative: fixed weir with submersible decant pump. Floating decanter provides smoother decant and less carryover risk.
Decanter: Floating PP V-notch decanter recommended for controlled decant. Alternative: fixed weir with submersible decant pump. Floating decanter provides smoother decant and less carryover risk.
Polishing, Disinfection & Add-ons
- Pressure Sand Filter (PSF) → Activated Carbon Filter (ACF) for turbidity & organics removal.
- Online hypochlorite dosing for disinfection; optional UV for additional pathogen control.
- Optional UF / RO for high-grade reuse (RO feed / cooling towers) — recommended when reuse demands are strict.
- PLC timer controls all SBR cycle phases; alarms & DO control recommended.
Expected Performance & Reuse
| 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 |
Typical reuse: gardening, toilet flushing, car wash and pavement cleaning. For RO feed or critical reuse include UF/RO and conduct lab validation.
Operation & Maintenance (Key points)
- Program SBR cycles on PLC; adjust Fill/React/Settle times based on load and performance.
- Maintain DO during React: 2.0 – 3.5 mg/L. Use online DO controller if possible.
- Monitor MLSS & SVI weekly; manage sludge wasting and dewatering schedule.
- Inspect decanter & V-notch regularly to prevent solids carryover.
- Blower and diffuser maintenance; periodic cleaning and spare parts on hand.
- Keep logbook for TNPCB/CPCB compliance and operation records.
Get Quick Quotation / Technical Proposal
Free site visit & jar test for final design & price. Send site photos, sample report (if available) and project brief.
Contact
Sales / Technical: +91 97100 35249 • Service: +91 99623 95875 • Email: rrrenviro@gmail.com
Sales / Technical: +91 97100 35249 • Service: +91 99623 95875 • Email: rrrenviro@gmail.com