300 KLD STP - SBR & MBR

Page Summary

This single page contains side-by-side technical & commercial information for both **300 KLD SBR** and **300 KLD MBR**. Default design basis: 20 operating hours/day, assumed influent BOD₅ = 250 mg/L. Final guarantees provided after site survey and raw influent lab report (BOD, COD, TSS, TDS, FOG, pH).

Applications: Apartments, Villas, Commercial complexes, Institutions, Industrial estates (Same as confirmed).

Common Front-End Process (Applies to SBR & MBR)

Bar Screen → Oil & Grease Trap → Grit Chamber → Collection / Equalization Tank (with mixer & level control) → Raw Sewage Pump → (SBR Reactor OR MBR Reactor) → (Secondary Clarifier for SBR) → (Membrane tank for MBR) → Polishing Filters (PSF / ACF / UF) → Disinfection & Treated Water Tank → Reuse / Discharge.

Disinfection method: SBR → Hypo (Sodium Hypochlorite), MBR → UV + Hypo (confirmed).

300 KLD — SBR (Sequencing Batch Reactor) Technical Details

Process Overview

SBR is a fill–react–settle–decant batch system that runs cycles (Fill → React (Aeration) → Settle → Decant → Idle). It gives excellent control over reaction time and settling and is flexible for variable loads.

Design Basis (SBR) — Digit-by-Digit

Q_day = 300 m³/day (300 KLD)
Operating hours = 20 hr/day (default)

Step 1 — Hourly flow
Q_hr = 300 ÷ 20 = 15.000 m³/hr = 15,000 LPH.

Q_hr = 300 ÷ 20 = 15.000 m³/hr → 15,000 LPH

Step 2 — SBR cycle & reactor volume
Typical SBR cycle chosen = 6 hours (Fill 0.5 h, React 3.0 h, Settle 1.5 h, Decant 0.5 h, Idle 0.5 h).
Reactor Volume V = Q_hr × cycle_time = 15.0 × 6 = 90.0 m³ (90,000 L). Include 15% freeboard → physical volume ≈ 103.5 m³.

V_sbr = 15 × 6 = 90.0 m³ → V_physical ≈ 90 × 1.15 = 103.5 m³

Step 3 — MLSS & Biomass
Assume MLSS = 3,000 mg/L (3.0 kg/m³). Biomass mass = 3.0 × 90.0 = 270 kg.

MLSS mass = 3.0 × 90 = 270 kg

Step 4 — BOD load & O₂ requirement
BOD load/day = 300 × 250 ÷ 1000 = 75 kg/day.
O₂ req ≈ 75 × 1.4 = 105 kg O₂/day.
Conservative blower sizing (1.2 kg O₂/kW) → 105 ÷ 1.2 ≈ 87.5 kW → recommend multiple blowers totalling ~90–100 kW with VFD & redundancy.

BOD=75 kg/day → O2≈105 kg/day → blower≈87.5 kW → select ~90–100 kW (split)

Step 5 — Decant balance & cycles
With 6-hour cycle and 20 hr operation → cycles/day ≈ 20 ÷ 6 = 3.33 cycles/day. Decant fraction typically 30–40% of reactor → decant per cycle ~ 90 × 0.33 ≈ 29.7 m³; daily decant ≈ 29.7 × 3.33 ≈ 99 m³ (≈ 300 m³/day with rounding) — consistent with flow.

Cycles/day = 20 ÷ 6 = 3.33 → decant/cycle ≈ 90 × 0.33 ≈ 29.7 m³ → daily ≈ 99 m³ ≈ 300 m³/day

Step 6 — Sludge
Sludge yield ~0.5 kg DS/kg BOD → DS/day ≈ 75 × 0.5 = 37.5 kg DS/day. At 3% cake → wet ~1,250 L/day.

DS/day = 37.5 kg → wet ≈ 37.5 ÷ 0.03 ≈ 1250 L/day

SBR Equipment & Scope

SBR reactor tank(s) with inlet, decant weir or submersible decanter, internal baffles
Fine bubble diffusers & blowers (~90–100 kW distributed)
Raw sewage pumps (duty+standby), decant pumps, RAS pumps
Polishing filters (PSF / ACF / UF) & Hypo dosing skid for disinfection (SBR → Hypo)
PLC panel for SBR cycle control, level sensors, DO sensor
Sludge sump, thickener, dewatering (filter press / centrifuge / drying bed)
Piping, valves, civil foundation & installation

SBR Advantages & Use Cases

Compact, good for variable/intermittent flows, easy to tune cycle times. Ideal for retrofits, apartment complexes and sites needing flexible operation.

300 KLD — MBR (Membrane Bioreactor) Technical Details

Process Overview

MBR couples biological treatment with membrane filtration (submerged membranes commonly). Eliminates need for large clarifiers, gives superior TSS removal and high-quality permeate suitable for reuse (with UV + Hypo). Best where footprint or effluent standards are tight.

Design Basis (MBR) — Digit-by-Digit

Q_day = 300 m³/day
Operating hours = 20 hr/day → Q_hr = 15.000 m³/hr → 15,000 LPH

Step 1 — Flow
Q_hr = 300 ÷ 20 = 15.000 m³/hr (15,000 LPH).

Q_hr = 15,000 LPH

Step 2 — Membrane area (flux method)
Choose conservative design flux = 10 LMH (litres/m²·hr) for submerged membranes. Required membrane area A = 15,000 ÷ 10 = 1,500 m² total membrane area.

A = 15,000 ÷ 10 = 1,500 m²

If modules have 10 m² active area → modules ≈ 150 modules (vendor dependent — final after vendor selection). This is a large area: confirm vendor flux & pilot performance.

Step 3 — Reactor volume & MLSS
Choose HRT = 4 hours → V_bio = Q_hr × HRT = 15.0 × 4 = 60.0 m³ working volume (60,000 L).
MBR MLSS is high — assume MLSS = 8,000 mg/L (8.0 kg/m³). Biomass mass = 8.0 × 60.0 = 480 kg.

V_bio=15×4=60 m³; MLSS=8kg/m³; Biomass=8×60=480 kg

Step 4 — BOD & O₂
BOD load/day = 300 × 250 ÷ 1000 = 75 kg/day.
O₂ req ≈ 75 × 1.4 = 105 kg O₂/day.
Blower sizing with scouring: assume 1.2 kg O₂/kW then add 20% for scouring → blower_kW ≈ (105 ÷ 1.2) × 1.2 ≈ 105 kW practical total (split across multiple blowers, e.g., 4 × 30 kW).

BOD=75 → O2=105 kg/day → blower_kW ≈ 105 kW (with scouring allowance)

Step 5 — Sludge
MBR sludge yield lower (use 0.4 kg DS/kg BOD) → DS/day = 75 × 0.4 = 30 kg DS/day. At 3% cake → wet ≈ 30 ÷ 0.03 = 1,000 L/day.

DS/day=30 kg → wet ≈ 1,000 L/day

MBR Equipment & Scope

Screening, Grit & Oil-Grease trap
Equalization tank & raw pump
MBR tank with submerged membrane modules (total area ~1,500 m² assumed)
Blowers for aeration & membrane scouring (total ~100–110 kW split)
Permeate pumps, permeate headers, CIP connections for membrane cleaning
Post-treatment: UV + Hypo dosing and polishing filters
PLC with membrane control, TMP monitoring, DO control & remote telemetry
Sludge sump & dewatering equipment (filter press / centrifuge)

MBR Advantages & Use Cases

Very high quality effluent (low TSS & turbidity), small footprint compared to clarifier-based systems, ideal for reuse (toilet flushing, cooling) and projects with strict discharge limits.

Tech Comparison Summary — SBR vs MBR (for 300 KLD)

Parameter	SBR (300 KLD)	MBR (300 KLD)
Footprint	Moderate (clarifier included)	Smaller (no large clarifier; membrane area racks)
Effluent TSS	< 30–50 mg/L (with polishing)	< 5–10 mg/L (excellent)
Sludge	~37.5 kg DS/day	~30 kg DS/day
Power (approx.)	~90–100 kW (blowers+pumps)	~100–110 kW (blowers+pumps + scouring)
Capex	Lower	Higher (membranes & CIP)
Opex	Moderate	Higher (membrane maintenance & cleaning chemicals)
Use case	Flexible, good for batch/variable loads	Reuse-critical, strict discharge limits, space constrained

Regulatory Compliance & Documentation

Both SBR and MBR designs will be engineered to meet TNPCB / CPCB discharge standards. Scope includes sampling ports, monitoring points, documentation support for consent & statutory approvals, and assistance with performance test certificates after commissioning.

Operation & Maintenance (Common Notes)

Daily: check screens, pumps, air blowers, DO, pH and cycle logic (SBR) or TMP & flux (MBR).
Weekly: clean screens & grit trap, check diffuser performance and ragging issues.
Monthly: calibrate sensors, blower service, membrane CIP scheduling (MBR) and sludge management.
Periodic: sludge dewatering & disposal, chemical top-ups for dosing & CIP, operator training.
We offer AMC and remote monitoring packages for both SBR and MBR installations.

Item

Indicative Cost (INR)

Mechanical Equipment (pumps, blowers)

₹ xx,xx,xxx

Reactor Tanks & Civil

₹ xx,xx,xxx

Membranes (MBR only)

₹ xx,xx,xxx

Polishing & Disinfection

₹ xx,xx,xxx

Installation & Commissioning

₹ xx,xx,xxx

GST

Extra

FAQ — 300 KLD SBR & MBR

Q1: Which technology is best for limited land?

MBR typically has smaller footprint due to elimination of secondary clarifier; choose MBR when land is constrained and higher effluent quality is required.

Q2: What data do you need to finalise design?

Raw influent lab report: BOD, COD, TSS, TDS, Turbidity, FOG, pH, temperature, and any industrial contaminants. Also site drawings & electrical availability.

Q3: What disinfection do you recommend?

SBR: Sodium Hypochlorite dosing is a reliable choice. MBR: UV + Hypo provides robust barrier — UV for pathogen inactivation + Hypo for residual if needed.

Q4: Do you provide warranty & AMC?

Yes — standard equipment warranty and customizable AMC packages for preventive maintenance, spare parts and operator support.