20 KLD STP Price in Chennai- ASP
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20 KLD Sewage Treatment Plant — ASP Design
Turnkey: Design • Supply • Installation • Commissioning — Designed for 20 hours/day operation
Quick Overview
20 KLD (20,000 L/day) ASP sewage plant for apartments, hostels, small hotels or institutions. Compact layout with sludge return, PSF+ACF polishing and disinfection. Free site visit & jar test available.
A. Design Basis
Operating hours: 20 hours/day. Design hourly flow = Qd / 20 = 20,000 / 20 = 1,000 L/hr.
| Parameter | Value / Assumption |
|---|---|
| Design daily flow (Qd) | 20,000 L/day (20 KLD) |
| Operating hours | 20 hours/day |
| Design hourly flow (Qh) | 1,000 L/hour |
| Influent pH | 6.5 – 7.5 |
| Influent BOD (design) | 300 mg/L |
| Influent COD | 900 mg/L |
| Influent TSS | 150 mg/L |
| Oil & Grease | 50 mg/L |
| Target effluent | BOD < 30 mg/L, TSS < 30 mg/L (after polishing) |
B. Tank & Unit Sizing (20 h operation)
Hourly flow = 1,000 L/h. Volumes rounded to practical sizes.
| Unit | HRT / Note | Volume (L) | Volume (m³) |
|---|---|---|---|
| Equalization Tank | 6 hours | 1,000 × 6 = 6,000 | 6.0 |
| Grit / O&G Chamber | 0.5–1 hour | ~1,000 | 1.0 |
| Aeration Tank (ASP) | 6 hours (MLSS 2000–3500 mg/L) | 1,000 × 6 = 6,000 | 6.0 |
| Secondary Clarifier | 2 hours | 1,000 × 2 = 2,000 | 2.0 |
| Clarified Water Tank (Buffer) | Buffer / PSF feed | ~600 | 0.6 |
| Polishing Filters (PSF + ACF) | Pressure vessels (sizes per flow) | – | – |
| Final Treated Water Tank | Reuse buffer | ~1,000 | 1.0 |
| Sludge holding / thickener | intermediate | ~1,000 | 1.0 |
| Total (approx) | ~17,600 L | ~17.6 m³ |
Tip: combine EQ + primary in one tank where space limited; use FRP/GRP modular tanks for rooftop installs.
C. Process Flow Diagram (with Sludge Return)
Collection Tank
⬇️
Aeration Tank (Diffused Air System)
⬇️
Secondary Settling Tank (Clarifier)
Sludge Return (RAS) → back to Aeration Tank
⬇️
Clarified Water Tank (Buffer)
⬇️
Pressure Sand Filter (PSF)
⬇️
Activated Carbon Filter (ACF)
⬇️
Hypo Dosing (Chlorination) / UV
⬇️
Final Treated Water Tank (Reuse / Discharge)
Excess sludge → Sludge holding → Filter press / Drying bed → Disposal as per norms.
D. Raw & Treated Sewage Characteristics (Design)
| Raw Sewage | Design Value |
|---|---|
| pH | 6.5 – 7.5 |
| BOD | ~300 mg/L |
| COD | ~900 mg/L |
| TSS | ~150 mg/L |
| Oil & Grease | ~50 mg/L |
| Treated Sewage | Expected Value |
|---|---|
| pH | 6.5 – 7.5 |
| BOD | < 30 mg/L |
| COD | < 100 mg/L (site dependent) |
| TSS | < 30 mg/L |
| Oil & Grease | < 5 mg/L |
E. Equipment & Turnkey Scope
- Bar screen, grit & O&G chamber
- Equalization tank with mixer
- Aeration tank with fine bubble diffusers + blower (approx 20–30 m³/hr recommended)
- Secondary clarifier with RAS & waste sludge pump
- Clarified water buffer, PSF, ACF & disinfection
- Sludge holding, filter press/drying bed
- PLC panel, sensors (DO, levels), alarms
- Commissioning, operator training & AMC options
Operation Notes
- Maintain DO 2.0–3.5 mg/L in aeration
- Weekly MLSS & SVI checks; adjust wasting
- Replace/clean PSF media & ACF as per pressure loss