Sizing a Containerized MBR STP for Lyon Projects (2026 Guide)

Why Sizing a Containerized MBR in Lyon Is Different from a Tropical Deployment

A containerized MBR STP is a pre-engineered membrane bioreactor assembled inside a standard 20 ft or 40 ft high-cube (HC) shipping container, integrating biological treatment with submerged ultrafiltration (UF) at a nominal pore size of 0.04 µm. The stock envelope is geography-agnostic: a 20 ft HC unit typically handles up to ~50 m³/day, a 40 ft HC unit covers ~50–200 m³/day, and multiple containers can be paralleled for larger flows (Pure Aqua, S4; WaterAcademia, S5). For Lyon projects, however, the integration envelope — voltage, ambient temperature, and compliance regime — is not geography-agnostic, and a sizing walkthrough written for West Africa does not survive the transfer unchanged.

Three integration mismatches are specific to a Lyon deployment. First, the stock electrical spec is 460V / 3Ph / 60Hz (Pure Aqua, S4), while the French grid is 400V / 3Ph / 50Hz; a step-down transformer or a voltage-matched build must be specified at quotation. Second, the stock operating band is 20–30 °C with a 20 °C design point (Pure Aqua, S4), and Lyon winter ambient falls below that band, so insulation, partial burial, or a low-temperature biological option has to be on the quotation. Third, French small-WWTP discharge is governed by the EU Urban Wastewater Treatment Directive 91/271/EEC together with the French Order of 21 July 2015 (which sets performance levels for small systems handling under 1.2 kg BOD/d), and the local SPANC (Service Public d'Assainissement Non Collectif) must be consulted before specifying effluent polishing. Confirm the receiving environment — sewer, surface watercourse, or irrigation reuse — because the polishing requirement changes with the discharge route.

For camps with 2–5 year horizons, phased housing, or worker accommodations, a containerized MBR remains a strong match for the Lyon area because the unit ships on a standard flatbed, drops on a concrete pad, and needs only power and piped influent to start up; the container can be lifted out and redeployed when the project ends.

Step 1 — Establish the Design Population and Per-Capita Flow

Design population is the primary sizing input and is regularly under-counted. The Thiès camp case study (S4) reminds engineers to include visitors, shift-changeover surges, and phased build-out, and to add 5–10% to the headcount for unaccounted occupancy; the same caution applies in Lyon. Multipliers are not generic: the per-capita flow depends on occupancy type, not on a stock baseline. Pure Aqua's stock baseline is 50 gpd (≈190 L) per capita per day (Pure Aqua, S4), but residential developments in Western Europe typically sit at 130–180 L/c/d when occupants are full-time and fixtures are efficient, while a labour camp with shared showers, kitchen messes, and laundry typically sits at 200–250 L/c/d (S4). Get the occupancy profile right before you commit.

Worked example for a 250-person construction camp east of Lyon with shared canteen and showers: 250 × 220 L = 55,000 L/day ≈ 55 m³/day average. Worked example for a 200-person full-time residential development with efficient fixtures: 200 × 150 L = 30,000 L/day = 30 m³/day average. Validate the per-capita value against an on-site water-use survey or metered data before locking it in, because the figure chosen here drives every downstream decision. A unit conversion reminder: 1 cubic metre = 1,000 litres (IDA Handbook 2019/2020-2021, S2/S3).

Step 2 — Convert Qavg to Qpeak with the Right Peak Factor

A membrane bioreactor's flux is rate-limited, so the unit must be sized for peak hourly flow (Qpeak), not the 24-hour average. The membrane tank's equalization volume is finite, and undersizing the peak causes transmembrane pressure spikes, shorter cleaning intervals, and compliance excursions during peak windows (Pure Aqua, S4). The peak factor (PF) is occupancy-dependent: 2.0–2.5 for camp occupancies and 1.5–1.8 for steady residential developments (Pure Aqua, S4).

Qpeak (m³/h) = Qavg (m³/day) × PF ÷ 24. For the 250-person camp example with Qavg of 55 m³/day and a PF of 2.2: Qpeak = 55 × 2.2 / 24 ≈ 5.0 m³/h. For the 200-person residential example with Qavg of 30 m³/day and a PF of 1.6: Qpeak = 30 × 1.6 / 24 = 2.0 m³/h. Extreme peak profiles — for example, a single morning wash block serving all workers in 90 minutes — should be mitigated with 4–6 hours of external buffer storage, as recommended for high-surge profiles (Pure Aqua, S4). A conservative engineer sizes for the worst observed 4-hour window rather than the 24-hour average.

Step 3 — Match Qpeak to the Container Envelope

Translating Qpeak into a specific container size requires adding 20–30% spare capacity above Qpeak for population growth, seasonal load spikes, and future reuse upgrades (Pure Aqua, S4). The envelope map is: 20 ft HC up to ~50 m³/day, 40 ft HC 50–200 m³/day, with multiple 40 ft units parallelable for larger flows (Pure Aqua, S4; WaterAcademia, S5). The 250-person camp example (Qavg 55 m³/day, Qpeak 5.0 m³/h) sits at the upper edge of a 20 ft HC envelope once spare capacity is added — the conservative call is a 40 ft HC unit, or two 20 ft units with one held as standby, mirroring the 300-person Thiès camp decision. The 200-person residential example (Qavg 30 m³/day, Qpeak 2.0 m³/h) fits a single 20 ft HC unit with 20–30% spare capacity and is the right baseline spec. For phased construction projects, install a 20 ft unit now, plumb the second pad, and add the second 20 ft when occupancy hits ~70% of design; the submerged membrane cassette inside either format can be expanded or replaced without replacing the container.

For a quotation-ready spec, request the containerized MBR membrane bioreactor system datasheet and confirm the submerged cassette geometry against the per-capita and peak values calculated above.

Step 4 — Check the Design Envelope Against Lyon Influent and Ambient

Verifying the unit's design envelope against site-specific influent and ambient conditions prevents the most common Lyon integration issues. The stock influent envelope is BOD 200–400 mg/L, COD 400–800 mg/L, and TSS 200–350 mg/L (Pure Aqua, S4); a 2-weekday + 1-weekend-day influent sampling campaign should be run on the Lyon site before finalizing the design, because French residential and camp sewage can deviate from this band. The stock operating temperature band is 20–30 °C with a 20 °C design point (Pure Aqua, S4); Lyon winter ambient falls below this, so specify insulation, container burial partial, or a low-temperature biological option at quotation, and confirm biological activity is maintained through the cold months. Pre-treatment is a 1.5 mm drum screen built into the stock unit (Pure Aqua, S4); camp greywater carrying sand, hair, and plastics can still overwhelm it if upstream grit removal is skipped. Electrical: the stock is 460V / 3Ph / 60Hz (Pure Aqua, S4) and the French grid is 400V / 3Ph / 50Hz — specify a step-down transformer or a voltage-matched build. Effluent from the MBR stage is near-reuse quality (BOD <5 mg/L, TSS <1 mg/L per Pure Aqua, S4), which supports Lyon-area reuse for toilet flushing or irrigation but may still need a polishing step to meet French small-system discharge limits — confirm with the local SPANC.

For the membrane stage geometry inside the envelope, see the PVDF flat sheet membrane module reference and confirm that submerged modules are individually replaceable so a single failed element does not require a full cassette change.

Step 5 — Lock In Compliance, Power Backup, and Operator Model

Wrapping the engineering calculation into a procurement-ready spec means addressing the four items that always come up in a French project review. First, compliance: confirm the receiving environment — ground irrigation, surface watercourse, or municipal sewer — and the relevant French small-WWTP standard before specifying effluent polishing. The French Order of 21 July 2015 sets performance levels for small systems handling under 1.2 kg BOD/d, and the local SPANC interprets it at the commune level. Second, power backup: a membrane plant without backup power trips on the first sustained outage; size a genset for the camp's expected outage rate, even though French grid reliability is higher than the West African baseline used in the Thiès case. Third, operator model: a fully automatic PLC control system is appropriate for camps with no full-time operator; add remote monitoring if the site is intermittently staffed. Fourth, spare parts: confirm that submerged PVDF flat-sheet membrane modules are individually replaceable so a single failed element does not require a full cassette change. Finally, lead time and rental: containerized MBR units for short-horizon camps (2–5 years) can be rented in many markets; confirm whether the Lyon supplier offers a rental-to-purchase path before committing to a CAPEX purchase, because the rental-versus-purchase decision is what a Lyon buyer on a short-horizon camp project actually weighs. For a parallel read on a central-European deployment with comparable climate and grid constraints, see the central-European containerized MBR sizing guide.

Frequently Asked Questions

What does a containerized MBR for a 200–400 person Lyon project actually cost in 2026?

Pricing for a packaged 20 ft or 40 ft MBR unit is project-specific and depends on the voltage-matched build, winterisation options, effluent polishing, and whether the unit is rented or purchased. The supplied research does not contain a 2026 price quotation for a Lyon-area containerized MBR, so a buyer should request a written quotation that itemises the container, the transformer or voltage-matched build, the winterisation package, the polishing step, delivery to site, and commissioning. Confirm whether the quote is CAPEX purchase, 2–5 year rental, or rental-to-purchase, and request the membrane replacement schedule and cost separately because membrane life drives the lifecycle cost.

How do I choose between a 20 ft and a 40 ft unit, and can I parallel them later?

Use the envelope rule: 20 ft HC for up to ~50 m³/day, 40 ft HC for 50–200 m³/day, with 20–30% spare capacity above Qpeak (Pure Aqua, S4; WaterAcademia, S5). The 250-person camp example in this article (Qavg 55 m³/day, Qpeak 5.0 m³/h) sits at the upper edge of a 20 ft envelope and is the conservative call for a 40 ft HC or 2 × 20 ft with one on standby. The 200-person residential example fits a single 20 ft HC. For phased projects, install a 20 ft now, plumb the pad, and add a second 20 ft when occupancy hits ~70% of design; the submerged cassette can be expanded without replacing the container.

Which French rules apply to a packaged MBR for a 100–400 person project, and how do I confirm them?

French small-WWTP discharge is governed by the EU Urban Wastewater Treatment Directive 91/271/EEC together with the French Order of 21 July 2015, which sets performance levels for systems handling under 1.2 kg BOD/d. The local SPANC interprets the Order at commune level and must be consulted before specifying effluent polishing. Confirm the receiving environment — sewer, surface watercourse, or irrigation reuse — because the polishing requirement changes with the discharge route. Submit the SPANC dossier (population, per-capita flow, peak factor, container envelope, winterisation measures, and effluent quality) as part of the permit application, and request written confirmation of the accepted discharge route before placing the equipment order.

What winterisation measures are required for a Lyon-area containerized MBR, and are they optional?

The stock operating band is 20–30 °C with a 20 °C design point (Pure Aqua, S4), and Lyon winter ambient falls below that band. The research identifies insulation, container burial partial, or a low-temperature biological option as the standard mitigation measures, but it does not specify a temperature threshold at which each measure becomes mandatory. Request from the supplier the minimum ambient temperature the quoted unit is rated for, the insulation R-value, the heat input of any heater option, and the biological activity expected at 5 °C influent. Confirm in writing that biological activity is maintained through the cold months and that membrane performance does not degrade below the quoted minimum ambient, because compliance excursions in winter are a common failure mode for stock units deployed in temperate climates.