Sewage Treatment Plant (STP) Solutions in Bangladesh
Compact biological sewage treatment for factories, commercial buildings and residential developments — including MBR systems sized for sites with no land to spare.
A Sewage Treatment Plant handles domestic wastewater — from toilets, kitchens, canteens and washrooms — rather than industrial process effluent. Because sewage is chemically far more predictable than factory effluent, treatment is overwhelmingly biological, and the design question becomes one of footprint, effluent quality target and how much operator attention the site can realistically provide.
Most industrial sites in Bangladesh need both an ETP and an STP: the production process and the workforce produce different wastewaters with different treatment requirements. WTBL designs both, and where the site is tight or the treated water is to be reused, specifies MBR to get a high-quality effluent out of a small footprint.
How a STP plant works.
- 01
Screening and grit removal
Bar screens and grit chambers remove rags, plastics and sand that would otherwise abrade pumps and settle in tanks. Skimping here is the most common cause of chronic maintenance complaints in a small STP.
- 02
Equalisation and balancing
Sewage flow peaks sharply at shift changes and meal times. Balancing that flow before biological treatment lets the plant be sized for average load rather than peak, which cuts both capital and running cost.
- 03
Biological treatment
Activated sludge, MBBR or MBR converts organic load and nutrients into biomass. MBBR adds carrier media to raise treatment capacity within an existing tank volume; MBR replaces the clarifier with a membrane and produces a far cleaner effluent from a smaller footprint.
- 04
Separation
Conventional plants use a secondary clarifier to separate biomass from treated water. MBR plants filter it through the membrane instead, which removes the clarifier entirely and makes effluent quality independent of sludge settling behaviour.
- 05
Disinfection and reuse
Chlorination or UV disinfects the treated effluent before discharge. Where the water is reused for irrigation, cooling tower make-up, flushing or floor washing, tertiary filtration is added to meet the reuse specification.
Scope of supply.
Technology selection
A recommendation between MBR, MBBR and conventional activated sludge based on available land, the effluent target, whether the water will be reused, and the operating budget — with the trade-offs stated rather than buried.
Underground and packaged plants
Where surface area is unavailable, treatment can be placed below ground or supplied as a packaged unit, which is common on commercial and residential developments.
Membrane supply and replacement
As an authorised DuPont Water Solutions distributor for RO, UF and MBR in Bangladesh, WTBL supplies and replaces MBR membranes for its own plants and for plants built by others.
Operation and maintenance
O&M contracts covering plant operation, membrane cleaning, sludge handling, spare parts and discharge monitoring.
Where STP systems are used.
- Garments and textile factories
- Commercial and office buildings
- Residential developments
- Hospitals and institutions
- Hotels and hospitality
- Economic zones
Talk to an engineer, not a form
Every plant is sized from the client's own effluent or feed water analysis. Send your figures and WTBL will come back with a process route and an indicative scope.
Contact WTBLTechnical documents
STP — Frequently Asked Questions
Straight answers to the questions buyers ask most often before commissioning a STP system.
What is a Sewage Treatment Plant (STP)?
An STP treats domestic sewage — from toilets, kitchens and washrooms — rather than industrial process effluent. Treatment is primarily biological, using processes such as activated sludge, MBBR or MBR to remove organic load and suspended solids before discharge or reuse.
What is the difference between an ETP and an STP?
The difference is the wastewater, not the building. An ETP handles industrial process effluent, which carries dyes, chemicals and variable pH and needs chemical treatment stages. An STP handles domestic sewage, which is chemically predictable and is treated almost entirely biologically. Factories with both worker facilities and a production process often need both.
Which STP technology is right for a garments factory or building?
MBR (Membrane Bio-Reactor) suits sites with limited land or a reuse requirement, because it produces a very high quality effluent in a small footprint. MBBR and conventional activated sludge cost less and suit sites where land is available and the treated water is discharged rather than reused. WTBL selects between them on footprint, effluent target and operating budget.
Can treated sewage be reused?
Yes. STP effluent polished through MBR or tertiary filtration is commonly reused for landscape irrigation, cooling tower make-up, toilet flushing and floor washing. Reuse reduces both freshwater abstraction and discharge volume, which matters most on sites with groundwater restrictions.