What a containerized MBR STP actually delivers
A containerized membrane bioreactor (MBR) is a packaged sewage treatment plant that combines activated-sludge biology with submerged ultrafiltration (UF) inside an ISO steel frame, eliminating the secondary clarifier used in conventional activated-sludge designs. MENA-Water describes the package as a plug-and-play system in which the membrane filtration unit — arranged on stainless steel frames — provides the solids–liquid separation, with continuous coarse-bubble air scouring to keep the membrane surface clean (containerized MBR system). Pure Aqua's MBR-C datasheet specifies the core membrane as a submerged hollow-fibre (HF) UF module in PVDF with a nominal pore size of 0.04 µm; an equivalent Hinada datasheet for the same product family lists 0.05–0.06 µm PVDF HF, so the OEM datasheet must always be checked at quotation stage (S4, S5).
On pathogen and solids performance, MENA-Water states that ultrafiltration in the MBR reduces virus and bacteria by 99.9999% and achieves complete retention of bacterial flocs, suspended solids, small colloids and viruses, which is the property that makes MBR product water a candidate for irrigation reuse under Chilean standard NCh 1333. Pure Aqua specifies a 1.5 mm drum screen upstream of the membrane to protect the fibre surface, fine-bubble diffusers in the aeration tank for biomass growth, and coarse-bubble diffusers at the submerged HF module for continuous air-scour cleaning. The published operating envelope is 24-hour operation, 20 °C design and 20–30 °C operating range, with an electrical supply of 460 V / 3 ph / 60 Hz — a supply that has to be re-specified for Chile's 50 Hz, 380 V grid (S4).
On maintenance, MENA-Water notes that the membranes "don't need regular chemical cleaning except one or two maintenance clearings per year" rather than the routine CIP that a cassette UF system would require. An anoxic zone for denitrification is an available add-on (S4), relevant when the effluent must meet total-nitrogen limits for irrigation reuse.
Converting occupancy in Santiago into m³/day
The first engineering move is to reframe the buyer's question from "which brand" to "what is the actual average daily flow the plant must treat". Pure Aqua's sizing table is built on 50 gpd per capita (approximately 190 Lpcd), which is the only per-capita figure anchored in the scraped research and is a defensible starting point for a residential block or a fully occupied camp (S4). For Santiago residential projects, NCh 1333 and DS 609 design values may give a lower allowance than 190 Lpcd because they reflect fixture counts and reuse assumptions, so confirm the local design standard before locking the per-capita figure. The formula the engineer applies is:
Average daily flow (m³/day) = Population × Per-capita allowance (Lpcd) ÷ 1000
Applied to the three reference occupancies in the table below, the formula yields an average daily flow the OEM can size against; the peaking factor is then applied on top of the average, not embedded in it.
| Occupancy scenario | Per-capita allowance | Average daily flow | Notes |
|---|---|---|---|
| 100 residents, residential block | 190 Lpcd (S4) | ≈ 19 m³/day | Below the practical containerized-MBR range; consider the underground A/O package |
| 500 residents, residential complex | 190 Lpcd (S4) | ≈ 95 m³/day | Comfortably inside the Hinada 80 m³/day envelope; expect single 20 ft or half-length container |
| 1,000 residents, large residential / camp | 190 Lpcd (S4) | ≈ 190 m³/day | Approaches the upper end of small packaged MBR; confirm with vendor |
Apply a peaking factor on top of the average: residential blocks typically peak at 1.3–1.5× average, while mining or construction camps with shift meals, communal showers and laundry routinely peak at ~2.0× average — request this as an explicit input from the OEM and never let it sit inside a "safety factor" the vendor applies invisibly. Camps are also not 24-hour-occupied like a residential block; the package plant must be rated for the simultaneous worst-case shift, not the nominal headcount. The full list of inputs the buyer must hand the vendor before any quotation is defensible is: raw water quality, target effluent standard, hourly peak flow, and influent temperature range.
Matching flow to a 20 ft or 40 ft ISO container
Two published reference points anchor the container-to-flow translation. MENA-Water states that more than 1,200 m³/day can be treated in a single 40 ft ISO container — the upper envelope, with the same ISO shell heavily duty-loaded (S1). Hinada publishes the lower anchor: an 80 m³/day packaged MBR in a 2.3 × 2.5 × 11.5 m (W × H × L) carbon-steel container, which is roughly half the length of a 40 ft ISO shell (S5). The two reference points bracket the residential and camp duty range: a 500-resident Santiago block at ~95 m³/day sits inside the Hinada envelope; a 1,000-resident complex at ~190 m³/day still sits well below the MENA-Water ceiling.
For the Chilean site, the container construction detail that matters is not the steel thickness but the ancillaries: Pure Aqua specifies insulated container walls, zero water leakage, enhanced container structure and seaworthy container, and the same datasheet confirms 40 ft and 20 ft high-cube (HC) options depending on capacity (S4). Electrical supply must be re-specified to 380 V / 3 ph / 50 Hz for the Chilean grid. Footprint on site is dominated by pipework, tanker access and sludge storage rather than the container itself, so the rule of thumb is to plan 1.5–2× the container plan area around it, and to request a GA drawing from the vendor before purchase.
| Reference point | Flow rate | Container envelope | Source |
|---|---|---|---|
| Lower anchor, packaged MBR | 80 m³/day | 2.3 × 2.5 × 11.5 m carbon-steel container (≈ half a 40 ft ISO) | Hinada product datasheet (S5) |
| Upper anchor, containerized MBR | > 1,200 m³/day | Single 40 ft ISO container, stainless internal tanks | MENA-Water product page (S1) |
| Typical residential block, Santiago | ≈ 95 m³/day (500 residents at 190 Lpcd) | Fits Hinada envelope; single 20 ft or short container | Derived from S4, S5 |
| Very small residential, < 20 m³/day | < 20 m³/day | Containerized MBR is over-specified; switch to underground A/O package | Engineering judgement against S4, S5 anchors |
For very small residential blocks under ~20 m³/day, a containerized MBR is over-specified and an underground A/O package such as the WSZ series is the more proportionate choice (S5).
Process train and biological design envelope
The reference packaged-MBR process train published by Hinada is Anaerobic Tank → Aerobic Tank (MBBR) → MBR Tank (membrane) → Control Room, with PLC automatic control and a Siemens PLC with MCGS touch-screen HMI (S5). Pure Aqua's drum-screen pre-treatment is specified at 1.5 mm perforation, ahead of the bioreactor; aeration is split between fine-bubble diffusers in the aeration tank for biomass growth and coarse-bubble diffusers at the submerged HF membrane for continuous air-scour cleaning (S4).
The membrane flux design window published by Hinada is 10–25 L/m²·h on 10 m² PVDF HF elements (model NM-RMBR-1010 / NM-MBR-1010), with the 0.05–0.06 µm pore-size range and a CNP-brand booster pump set (S5). This flux band has to be derated for colder-than-design influent, and it is the OEM's datasheet — not the engineer's first-principles calculation — that fixes the number of membrane modules per skid. Pure Aqua's biological envelope is 20 °C design and 20–30 °C operating range; for Santiago's central zone this is normally met year-round, but for high-altitude camps in the Andean foothills or altiplano edge, where winter influent can sit below 10 °C, the plant must be housed, insulated and the MLSS/HRT reviewed (S4).
| Process train element | Specification | Source |
|---|---|---|
| Pre-treatment | 1.5 mm drum screen | S4 |
| Biological stage | Anaerobic → Aerobic (MBBR) → MBR tank | S5 |
| Aeration, biology | Fine-bubble diffusers in aeration tank | S4 |
| Aeration, membrane scour | Coarse-bubble diffusers at submerged HF module | S4 |
| Membrane element | PVDF hollow fibre, 10 m² per element, 0.05–0.06 µm pore size | S5 |
| Membrane flux design | 10–25 L/m²·h | S5 |
| Design temperature | 20 °C | S4 |
| Operating temperature | 20–30 °C | S4 |
| Denitrification | Anoxic zone add-on for NO₃ removal | S4 |
An anoxic zone is an available add-on (S4) — relevant when the camp discharges to a sensitive receiving water or reuses for irrigation under NCh 1333, and a useful review item on the vendor datasheet. The broader design envelope is treated in the MBR design criteria for sewage engineering guide.
Chilean compliance pathway for Santiago projects
Two compliance routes cover essentially every Santiago residential or camp project: discharge to the sewer network under DS 609/1998 (MINSEGPRES), or reuse for irrigation under NCh 1333. The choice changes the post-treatment train — discharge to sewer requires only that the MBR meet DS 609 pollutant limits, whereas reuse under NCh 1333 typically requires additional disinfection, and the MBR's <1 µm filtration already produces a low-TSS, low-BOD effluent that needs polishing, not additional solids removal (S4). Hinada explicitly lists tourist facilities, camps, refugee camps and remote communities as target applications for the containerized MBR (S5).
For any camp or residential project in the Santiago Metropolitan Region, the local SEREMI de Salud and Aguas Andinas (or the relevant rural APR for sites outside the concession area) must be engaged before the OEM selection is finalised; this article does not constitute legal advice and the project engineer must confirm the current local requirements. For high-altitude Andean camps, add an explicit altitude derating note on blower sizing and pump NPSHa — these are standard supplier checklist items, not optional extras. Where reuse is the target, UV polishing for reuse is the post-treatment step most commonly paired with the MBR effluent.
Containerized MBR vs underground A/O package — when to switch
The buried A/O package handles 1–80 m³/h in a buried footprint, is fully automatic, and requires no permanent operator — relevant for residential estates and small lodges in Santiago where land is at a premium and the unit can sit under landscaping. The containerized MBR is the better fit where the project is mobile, time-limited (camp, construction village, refugee camp — explicitly listed by Hinada, S5), needs reuse-quality effluent, or must be redeployed. The decision line is therefore:
| Duty | Recommended package | Rationale |
|---|---|---|
| Under ~20 m³/day, permanent installation | Underground A/O package (WSZ series) | Containerized MBR is over-specified; buried unit frees up the plan area |
| 20–50 m³/day, permanent residential | Either, depending on land and reuse target | Match the package to the reuse decision first, then to the site |
| Above ~50 m³/day, reuse-quality required | Containerized MBR | MBR effluent meets irrigation reuse limits with disinfection only |
| Temporary or relocatable camp duty | Containerized MBR | Plug-and-play ISO shell, redeployable |
The underground A/O package STP is the proportionate answer for a small residential block, while a containerized MBR is the right answer for a 500-person camp on a high-altitude site that must be redeployed at mine closure. The same logic is applied at higher altitude in the Andean containerized MBR sizing for La Paz guide.
Frequently Asked Questions
What per-capita flow should I use to size a containerized MBR STP for a Santiago residential project?
Use a defensible per-capita allowance and apply it as a formula, not as a fixed catalogue number. Pure Aqua's sizing table is built on 50 gpd per capita, which is approximately 190 Lpcd, and is the only per-capita figure anchored in the scraped research (S4). For Santiago residential projects, the local design standard may give a lower figure because it accounts for fixture counts and reuse assumptions, so confirm the local value before locking the number. Apply a peaking factor of 1.3–1.5× for residential and ~2.0× for camps, and request the vendor to state the factor explicitly rather than absorbing it into a hidden safety margin.
How many ISO containers do I need, and should I specify a 20 ft or 40 ft shell?
Translate the m³/day figure against two published anchors: MENA-Water's statement that more than 1,200 m³/day can be treated in a single 40 ft ISO container (S1), and Hinada's published 80 m³/day package in a 2.3 × 2.5 × 11.5 m carbon-steel container, which is roughly half a 40 ft ISO (S5). Most Santiago residential and camp duties sit between these anchors and will fit a single 20 ft or 40 ft HC container. Plan 1.5–2× the container plan area around it for pipework, tanker access and sludge storage, and request a GA drawing from the vendor before purchase.
What should I have on hand before requesting a vendor quotation?
Hand the vendor four explicit inputs so the quotation is comparable across suppliers: raw water quality, target effluent standard, hourly peak flow, and influent temperature range. Hinada's quotation request form asks exactly for raw water quality report, output water quality standard, and treatment capacity per hour (S5), and the same four inputs let the engineer check the MBR design temperature of 20 °C and the operating range of 20–30 °C (S4) against the actual site. Without these inputs the vendor will quote a default envelope and the engineer will have no basis to compare competing bids.
Do I discharge under DS 609/1998 or reuse under NCh 1333, and how does that change the package?
Discharge to the sewer network in Santiago is governed by DS 609/1998 (MINSEGPRES), and reuse for irrigation is governed by NCh 1333. The two routes change the post-treatment train: DS 609 needs the MBR to meet the sewer discharge limits, while NCh 1333 typically requires additional disinfection, and the MBR's <1 µm filtration already produces a low-TSS, low-BOD effluent (S4). Whichever route applies, engage the local SEREMI de Salud and Aguas Andinas (or the relevant rural APR) before the OEM selection is finalised — confirm the current local requirements with the project engineer, and pair the MBR with UV polishing for reuse where NCh 1333 reuse is the target. Comparable European context is laid out in the containerized MBR sizing for European duty guide.
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