Status: Delivered · Region: Middle East · Ref. D-039
What We Delivered
We delivered a containerised MBR sewage treatment plant for a new residential development in the Middle East serving ~2,000 households, approximately 5,000 population equivalent (PE). No design flow was nominated at the outset, so the design capacity, container count, footprint and power demand were derived from the population served — the derivation set out below. The client is a residential developer; its identity, the site and the contract terms are withheld under our client-confidentiality policy.
The design basis came to 750 m³/day (31.3 m³/h average, 78–94 m³/h hydraulic peak), approximately 610 m³ of biological volume and approximately 1,740 m² of membrane area at 18 LMH. The plant was delivered in containerised format because the site had no civil-works programme. Supplied equipment comprised the MBR process system, membrane modules and racks, and inlet screening.
| Parameter | Value |
|---|---|
| Development size | ~2,000 dwellings |
| Design population | ~5,000 PE |
| Design flow | 750 m³/day |
| Delivery format | Containerised (site had no civil works programme) |
| Process | MBR (client basis: MBR or equivalent advanced biological treatment) |
| Region | Middle East |
Source: client-supplied design basis; design flow from the calculation in Step 1.
Delivery Record
The project ran through nine delivery stages. The table lists what each stage covered on this project and the record it produced.
| Stage | What it covered on this project | Record produced |
|---|---|---|
| 1. Design basis confirmation | The population served (~2,000 households, ~5,000 PE) converted into design flow at 150 L/PE·day with a 2.5–3.0 peaking factor (750 m³/day average, 78–94 m³/h peak) and into organic load at 60 g BOD₅/PE·day (300 kg BOD₅/day); effluent specification fixed against the applicable discharge or reuse requirement. | Design basis sheet |
| 2. Process & mechanical design | Biological volume (approximately 470 m³ aerobic + 140 m³ anoxic at 8,000 mg/L MLSS and F/M 0.08), membrane area (approximately 1,740 m² at 18 LMH), allocation of biology, membrane tanks, equipment room and screening/balancing to 40 ft high-cube containers, and power demand (roughly 750 kWh/day, about 31 kW average). | Process calculation sheet, P&ID, container layout and GA drawings, electrical load list |
| 3. Manufacturing & quality control | Fabrication and fit-out of the process containers and equipment room; membrane modules and racks; rotary mechanical bar screen. | Material and quality-control inspection records |
| 4. Factory acceptance test (FAT) | Pre-dispatch function check of blowers, control panel, CIP and dosing equipment. | FAT record |
| 5. Packing & dispatch | Containers and associated equipment packed and dispatched for shipment to site. | Packing list and dispatch documents |
| 6. Installation (per contract scope) | Placement and interconnection of the containerised units on a site without a civil-works programme. | Installation record |
| 7. Commissioning | Start-up of the biological process, balancing control, membrane operation at the design flux and establishment of the chemical-cleaning (CIP) routine. | Commissioning log |
| 8. Performance verification | Hydraulic throughput checked against the design flow, and effluent quality against the effluent specification fixed for the site. | Performance test record against the design values |
| 9. Training & handover / after-sales | Operator training on running at design flux, the chemical-cleaning regime and membrane replacement planning. After-sales support per contract scope. | O&M manual, training record, handover record |
Delivery records for this project are on file and can be reviewed by qualified buyers under a confidentiality agreement.
Designed For
- A population-based brief — no nominated design flow; capacity derived from PE.
- Region-specific per-capita flow — a 150 L/PE·day design basis (see Step 1).
- Small-catchment peaking — a 2.5–3.0 peaking factor that sizes pipework, pumps and the membrane tank.
- A site without a civil-works programme — full containerisation.
- Membrane life — inlet screening and a conservative 18 LMH design flux.
Step 1 — From Population Equivalent to Design Flow
PE is a load unit, not a flow unit. Converting it requires a per-capita wastewater figure, and that figure is region-specific: arid-climate residential developments typically generate less wastewater per person than temperate ones, because outdoor water use does not reach the sewer.
At a design basis of 150 L/PE·day of sewage, 5,000 PE produces 750 m³/day — an average of 31.3 m³/h. Small residential catchments do not deliver that flow evenly: a peaking factor of 2.5–3.0 is normal at this population, which puts the hydraulic peak at roughly 78–94 m³/h.
This is the number that sizes the pipework, the pumps and the membrane tank — not the daily average. A plant designed only to the 31.3 m³/h average will surcharge every morning.
Source: HydropureWater design calculation. The 150 L/PE·day basis and the 2.5–3.0 peaking factor are standard engineering values for residential catchments of this size.
Step 2 — Organic Load and Biological Volume
The organic load follows directly from PE. At the conventional 60 g BOD₅ per PE per day, 5,000 PE generates 300 kg BOD₅/day.
An MBR carries this at an elevated mixed-liquor concentration. At 8,000 mg/L MLSS and a food-to-microorganism ratio of 0.08 kg BOD/kg MLSS·day:
| Step | Calculation | Result |
|---|---|---|
| Daily BOD load | 5,000 PE × 60 g/PE·d | 300 kg BOD₅/d |
| Required MLSS mass | 300 ÷ 0.08 | 3,750 kg |
| Aerobic volume | 3,750 kg ÷ 8 kg/m³ | ≈ 470 m³ |
| Anoxic volume (denitrification) | ≈ 30% of aerobic | ≈ 140 m³ |
| Total biological volume | — | ≈ 610 m³ |
Source: HydropureWater design calculation using standard MBR design parameters.
Step 3 — Membrane Area
Membrane area is set by continuous throughput, not by peak flow, provided a balancing tank absorbs the diurnal swing. At 750 m³/day treated over 24 hours — 31.3 m³/h — and a conservative design flux of 18 LMH:
31,300 L/h ÷ 18 L/m²·h ≈ 1,740 m² of membrane area.
Design flux is a decisive number in any MBR quotation. A supplier quoting 25–30 LMH will show a smaller, cheaper membrane package — and will spend the plant's operating life fighting fouling and chemical cleaning frequency. We size at 18 LMH deliberately.
Source: HydropureWater design calculation.
Step 4 — Container Count and Footprint
A 40 ft high-cube container offers roughly 67 m³ of gross internal volume, of which about 80% is usable as process volume once walkways, pipework and freeboard are deducted — call it 54 m³ per container.
Container allocation from the sizing calculation
| Function | Volume / duty | 40 ft HC containers |
|---|---|---|
| Anoxic + aerobic biology | ≈ 610 m³ | 11–12 |
| Membrane tanks | ≈ 1,740 m² membrane | 2–3 |
| Blowers, panel, CIP, dosing | Equipment room | 1 |
| Screening + balancing | Peak absorption | 2 |
| Total from the sizing calculation | — | 16–18 |
The ranges above are the sizing method. The as-built container arrangement is recorded in the container layout and GA drawings listed under Delivery Record.
At 5,000 PE the container count is high enough that a hybrid arrangement — containerised equipment and membranes, site-built concrete tanks for the biology — is usually more economical wherever a construction programme can be run. Containerisation earns its premium at small and mid scale, or where a construction programme genuinely cannot be run. This site had no civil-works programme, which is why the plant was delivered fully containerised.
Source: HydropureWater design calculation.
Step 5 — Power Demand
MBR plants consume 0.8–1.5 kWh per m³ treated, with aeration — process air plus membrane scouring — accounting for the majority. At 1.0 kWh/m³, a 750 m³/day plant draws roughly 750 kWh/day, about 31 kW average, with installed capacity higher to cover peak scouring and standby duty.
Source: HydropureWater design calculation using published MBR specific-energy ranges.
Membrane Life and Replacement Planning
Membrane life on municipal-strength sewage is typically 5–8 years when the plant runs at design flux and the cleaning regime is maintained. Two habits shorten it more than anything else: sustained operation above design flux, and deferred chemical cleaning. Both are invisible in year one and expensive in year four.
Equipment Delivered
- MBR integrated wastewater treatment system — biological and membrane process core.
- MBR membrane modules — membrane modules and racks.
- Rotary mechanical bar screen — inlet screening, without which membrane life is not defensible.
The technology trade-off behind this selection is set out in our MBR vs MBBR comparison.
For Similar Projects
- Confirm the per-capita flow and peaking factor used above against local water-consumption records before fixing plant capacity.
- Container count follows the membrane module and tank geometry you select.
- Above about 16 forty-foot containers, compare full containerisation with a hybrid (containerised equipment, site-built biological tanks) on total cost before ordering.
- When comparing MBR bids, compare the design flux before comparing the price.
- Where the grid is unreliable, establish power demand before the plant is ordered so that generator sizing can be settled in parallel.
- Provision a membrane replacement budget from commissioning, rather than raising it as a surprise capital request when the first modules reach end of life.
- Fix the effluent specification against the actual discharge permit or reuse regulation before the process is finalised.
Frequently Asked Questions
How many m³/day is 5,000 PE?
It depends on the per-capita wastewater basis, which is why no supplier should quote from PE alone. At 150 L/PE·day the answer is 750 m³/day; at 200 L/PE·day it is 1,000 m³/day — a third more plant. Always confirm the local figure against actual water-consumption records before fixing capacity.
How many containers does a 5,000 PE MBR need?
Indicatively 16–18 forty-foot high-cube containers once biology, membranes, equipment room and balancing are counted. At that number, hybrid delivery — containerised equipment with site-built concrete biological tanks — is usually more economical than full containerisation wherever a civil-works programme can be run.
What design flux should an MBR be sized at?
We size at 18 LMH for municipal-strength sewage. Quotations built on 25–30 LMH look cheaper because they carry less membrane area, but they buy that saving with higher fouling rates, more frequent chemical cleaning and shorter membrane life. When comparing MBR bids, compare the flux before comparing the price.
How long do MBR membranes last?
Typically 5–8 years on municipal sewage at design flux with a maintained cleaning regime. Running above design flux and deferring chemical cleans are the two habits that shorten it most.
What effluent standard can a containerised MBR meet?
An MBR reliably produces effluent suitable for discharge and, in many cases, for non-potable reuse such as landscape irrigation. The binding standard is whichever the local authority applies, so the effluent specification must be fixed against the actual discharge permit or reuse regulation before the process is finalised — not assumed from a technology datasheet.
