Advanced biological wastewater treatment systems including MBBR, SBR, MBR, EGSB, and traditional activated sludge reactors for effective organic matter removal and nutrient reduction.
CFD, P&ID, SCADA and commissioning for critical water treatment plants.
Plant layouts, piping isometrics and construction-ready engineering drawings.
Flow, mixing and thermal CFD across treatment and process equipment.
Full mechanical, physico-chemical, biological and sludge equipment range.
Behind the design sits a full modelling toolkit — CFD, process simulation, biokinetic (ASM/ADM), reaction-kinetics, hydraulic, limnological and data-driven digital-twin modelling. We pick, or combine, the disciplines that answer your question and validate them against real data.
Explore Scientific ModellingMicrobial Degradation Process
Biological treatment harnesses the power of microorganisms to break down organic pollutants in wastewater. Different technologies optimise this process for specific applications, flow rates, and treatment requirements.
Screening & grit removal
Microbial degradation
Solids separation
Polishing treatment
Clean water out
Uses biomass carriers for microorganisms to degrade contaminants. Carriers move freely in reactor ensuring effective contact. High efficiency and low operating requirements for industrial and municipal WWTPs.
High surface area
Optimal contact
Protected biomass
Smaller footprint than conventional activated sludge systems
Simpler operation without return activated sludge pumping
Protected biofilm handles variable loading conditions
Can be retrofitted into existing tanks
Sequential advanced biological treatment where all process stages (aeration, settling, decanting) occur in single tank. Automatic control enables nitrification, denitrification, and dephosphatation. Highly resistant to variable flows and loads, ideal for industrial facilities.
Wastewater inlet
60 – 120 min
Aeration + mixing
120 – 240 min
Solids separation
45 – 90 min
Clean water out
30 – 60 min
Standby / waste sludge
15 – 30 min
Combines biological decomposition with membrane filtration. High efficiency enables innovative water recovery for reuse. Compact design with high-quality effluent.
Produces water suitable for reuse with very low TSS and turbidity
Eliminates secondary clarifier; most compact advanced biological treatment
MLSS up to 12 g/L enables smaller reactor volumes
Effluent meets stringent standards for direct reuse applications
High-rate anaerobic treatment using granular sludge in an upflow configuration. EGSB handles very high organic loads (10–30 kg COD/m³·d), produces biogas rich in methane (CH₄ 65–75%, CO₂ 25–35%), and generates minimal excess sludge. Ideal for breweries, distilleries, food processing, and pharmaceutical wastewaters with high COD.
0.3–0.5 m³ biogas per kg CODremoved. Calorific value ~23 MJ/m³. Usable for boiler fuel, CHP, or process heat.
Dense granules (1–4 mm) with high methanogenic activity. Upflow velocity 3–10 m/h. Sludge volume index <30 mL/g.
No aeration energy. Low chemical demand. Sludge production 5–10% of aerobic systems. Positive energy balance possible.
Mesophilic (30–40°C) and thermophilic (50–60°C) operation. Insulated reactors with heat recovery from biogas combustion.
The traditional workhorse of biological wastewater treatment. Suspended-growth aerobic process with primary clarifier, aeration tank, and secondary clarifier. Reliable, well-understood, and efficient for large continuous flows with minimal variation.
Over 100 years of operational history. Extensive design guidelines and operator familiarity worldwide.
Simple tanks and diffusers. No membranes, carriers, or complex control systems. Lowest initial investment.
Ideal for >1,000 m³/d municipal plants. Proven at scales exceeding 1 MLD with minimal operator intervention.
Standard aeration equipment. Sludge volume index (SVI) monitoring. Conventional RAS/WAS pumping.
The Equations Behind Every Aeration Tank
Specific growth rate of heterotrophs scales with the limiting substrate concentration: μ = μmax·S / (KS + S). For municipal wastewater at 20 °C: μmax ≈ 6 d−1, half-saturation constant KS = 20–80 mg COD/L, yield Y = 0.4–0.6 g VSS/g COD, endogenous decay b = 0.05–0.10 d−1. Minimum SRT for stable operation: SRTmin = 1 / (Y·μmax·S/(KS+S) − b) — this is why nitrifying plants need SRT ≥ 8–15 d (nitrifier μmax is only ~0.7 d−1).
Field oxygen transfer rate: OTR = α·F·(SOTR)·[(β·CS20* − CL) / CS20*]·1.024(T−20). Fine-bubble diffusers achieve SOTE = 6–8%/m of submergence in clean water; the α-factor for activated sludge falls to 0.4–0.7. Oxygen demand: 1.0–1.5 kg O2/kg BODremoved for carbonaceous removal, plus 4.57 kg O2/kg N for nitrification. Energy cost is dominated by this term — aeration is 50–70% of plant electricity.
For a CSTR with biomass recycle: SRT = V·X / (Qw·Xw + Qe·Xe). Effluent substrate at steady state: S = KS·(1 + b·SRT) / [SRT·(Y·k − b) − 1]. SRT is the single most important design variable — it sets effluent quality, biomass yield, sludge production, and which microbial guilds (heterotrophs, nitrifiers, anammox) survive in the reactor.
Most biological rates follow the modified Arrhenius form kT = k20·θ(T−20) with θ = 1.04 for BOD removal, 1.08–1.12 for nitrification, 1.10–1.15 for denitrification, and 1.06–1.10 for methanogenesis. Below 10 °C nitrification effectively halts; below 15 °C anaerobic granular reactors lose 30–50% of design capacity unless heated.
Typical specifications for sizing advanced biological treatment equipment
SCADA Integration Available
Our advanced biological treatment systems feature advanced automation capabilities with SCADA integration. Monitor DO levels, control aeration, manage SBR cycles, and track biomass health from a centralised control interface. Double-redundant architecture ensures continuous operation for critical applications.
Select the Right Biological Treatment for Your Wastewater
| Feature | MBBR | SBR | MBR | EGSB | Conventional ASP |
|---|---|---|---|---|---|
| Footprint | Small | Medium | Smallest | Small | Large |
| Energy Use | Low | Medium | Medium-High | Very Low | Medium |
| HRT Range | 4 – 12 h | 8 – 24 h | 6 – 18 h | 4 – 24 h | 12 – 36 h |
| MLSS Range | 3 – 5 g/L | 3 – 5 g/L | 8 – 12 g/L | 15 – 40 g/L | 2 – 4 g/L |
| Organic Loading | 1 – 5 kg COD/m³·d | 0.5 – 2 kg COD/m³·d | 2 – 8 kg COD/m³·d | 10 – 30 kg COD/m³·d | 0.3 – 1 kg COD/m³·d |
| Nutrient Removal N / P | ~ Partial | ✓✓✓ Full | ✓✓ Good | ✗ None | ~ Partial |
| Water Reuse Quality | ✗ No | ~ Polishing needed | ✓✓✓ Direct reuse | ✗ No | ✗ No |
| Biogas Production | ✗ No | ✗ No | ✗ No | ✓✓✓ High yield | ✗ No |
| Shock Load Resistance | ✓✓✓ Excellent | ✓✓ Good | ✓ Moderate | ✓✓ Good | ✗ Poor |
| Temp. Range | 10 – 35°C | 10 – 35°C | 10 – 35°C | 25 – 40°C | 10 – 35°C |
| pH Range | 6.5 – 8.5 | 6.5 – 8.5 | 6.5 – 8.5 | 6.5 – 7.5 | 6.5 – 8.5 |
Match your wastewater characteristics and operational constraints to the optimal advanced biological treatment
| Industry / Application | Wastewater Profile | Recommended Technology | Key Rationale |
|---|---|---|---|
| Food & Beverage High COD, variable load | COD 2,000–15,000 mg/L, FOG, seasonal | MBBR or EGSB | MBBR resists shock loads; EGSB recovers biogas from high COD |
| Brewery / Distillery Very high COD, warm | COD 5,000–50,000 mg/L, warm (>25°C) | EGSB | Anaerobic pre-treatment removes 70–90% COD + biogas output. See brewery case study → |
| Pharmaceutical Strict effluent, reuse | Variable, trace APIs, tight N/P limits | MBR | Superior effluent for reuse or tight discharge. Complete solids retention. |
| Municipal WWTP Nutrient removal required | COD 300–600 mg/L, TN/TP limits | SBR or Conventional | SBR enables N/DN/DP in single tank. Conventional for >5 MLD. |
| Chemical / Industrial Toxic shocks, intermittent | Variable pH, inhibitors, batch discharges | MBBR | Protected biofilm resists toxic shocks. No sludge washout risk. |
| Meat / Poultry High protein, blood, fat | COD 3,000–10,000 mg/L, high TKN | MBBR + SBR | MBBR for COD; SBR for nitrification/denitrification of high TKN. |
| Dairy High fat, lactose | COD 1,000–5,000 mg/L, FOG | MBBR | Compact footprint. Handles FOG with DAF pre-treatment. |
Meeting Discharge Standards
Systems designed to meet BOD, COD, TSS, nitrogen, and phosphorus discharge limits per local regulations. Pilot testing validates effluent quality before full-scale commitment.
Reduce organic pollution load to receiving waters; recover energy through anaerobic processes
Low energy consumption, minimal chemical requirements, and reduced sludge disposal requirements through efficient dewatering.
Modular designs and containerised configurations allow easy capacity expansion and rapid deployment.
Complete Your Treatment System
Pre-treatment flotation for solids and oil removal before biological stages.
Explore Physico-ChemicalClarification for biological sludge separation and effluent polishing.
View Lamella ClarifierMulti-disc presses, belt presses, and centrifuges for biological sludge volume reduction.
View Sludge ManagementEqualization and buffer tanks for flow balancing and emergency storage in biological systems.
Storage TanksAeration tanks, contact tanks, and equalization vessels for advanced biological treatment processes.
Process TanksEngineering parameters for biological process design and equipment selection.
| Parameter | MBBR | SBR | MBR | EGSB | CAS |
|---|---|---|---|---|---|
| Design HRT (h) | 4–12 | 8–24 | 6–15 | 0.5–3 | 4–8 |
| OLR (kg BOD/m3·d) | 2–8 | 0.5–2.5 | 2–6 | 10–25 | 0.3–1.0 |
| MLSS (g/L) | 3–5 (film) | 2.5–4.0 | 8–12 | 15–40 (granules) | 2–4 |
| F/M ratio (kg BOD/kg MLSS·d) | 0.5–2.0 | 0.05–0.15 | 0.15–0.4 | — | 0.2–0.5 |
| SRT (d) | 10–30 | 10–30 | 15–40 | 30–100 | 3–15 |
| SOUR (mg O2/g MLVSS·h) | 15–40 | 10–30 | 10–25 | — | 15–40 |
| Specific energy (kWh/m3) | 0.15–0.35 | 0.20–0.45 | 0.50–1.20 | 0.05–0.15 | 0.25–0.50 |
| Sludge yield (kg DS/kg BODrem) | 0.50–0.75 | 0.60–0.90 | 0.70–1.00 | 0.05–0.15 | 0.60–0.90 |
| Typical effluent BOD (mg/L) | 10–25 | 10–20 | <5 | 50–200 | 15–30 |
These ranges are indicative at 20°C. Temperature correction (θ = 1.03–1.08) applies for cold-climate design. Reynolds & Bauhm calibrates design parameters against pilot data or plant benchmarking for each project.
Aeration accounts for 50–70% of total biological treatment energy. Fine-bubble diffusers achieve 4–6 kg O2/kWh vs 1.5–2.5 for coarse bubble. DO control with VFD blowers and automated valves typically reduces aeration energy 15–30%.
MBR membrane air scouring consumes 0.15–0.30 kWh/m3. Cyclic aeration, relaxation modes, and energy-efficient flat-sheet configurations reduce this by 20–40% compared to legacy hollow-fibre systems.
EGSB and UASB biogas yield 0.25–0.35 Nm3 CH4/kg CODrem. CHP conversion produces 1.5–2.5 kWh electricity per m3 biogas, often making anaerobic plants net energy positive.
Carbon intensity (kg CO2e/m3 treated): CAS 0.35–0.60; MBBR 0.25–0.45; MBR 0.50–0.90; EGSB −0.10 to +0.15 (net negative when biogas recovered). Scope 3 sludge transport adds 0.05–0.15 kg CO2e/m3.
The observed sludge yield Yobs decreases with increasing SRT due to endogenous respiration. At 20°C:
Px = Yobs × Q × (S0 − S)
Where Px = waste sludge production (kg TSS/d); Q = flow (m3/d); S0−S = BOD removed (kg/m3).
Reynolds & Bauhm designs sludge management as an integrated part of the biological treatment train, not an afterthought.
Aeration is the largest single energy consumer in biological treatment — choose the right type, sizing and control to optimise Operating expenditure.
Oxygen transfer rate, KLa, Henry’s Law and the alpha/beta/theta correction factors.
Read MoreFine-bubble vs coarse-bubble for activated sludge, MBBR and MBR — the energy-efficient default.
Read MoreMechanical paddle-wheel, brush, vertical-shaft turbine and floating aerators for oxidation ditches and lagoons.
Read MorePartial-mix and complete-mix lagoons for high-BOD industrial effluent.
Read MoreOur process engineers can run treatability studies, jar testing, and bench-scale trials to validate technology selection for your specific wastewater. Download our Biological Treatment Selection Guide or request a pilot study to generate design data with confidence.
Our expertise spans multiple industries with sector-specific water treatment solutions.