Many sites in the UAE treat their own wastewater instead of sending all of it to a public network. Some have no connection, some must meet limits before discharge, and many want to reuse the treated water for irrigation or cooling. For these sites a packaged wastewater treatment plant is often the practical choice: a factory-built unit that arrives ready to connect. One of the most common biological processes in these packages is the moving bed biofilm reactor, or MBBR. This article explains how it works and what you need to specify one.
What a packaged wastewater treatment plant is
A packaged plant combines the treatment stages in one or a few prefabricated tanks or skids. They are manufactured, assembled and tested in the factory, then delivered to site, where the work is mostly foundations, connections and commissioning. Compared with a plant built entirely on site, this shortens installation and keeps quality under factory control. It also suits buildings and industrial sites where space is tight.
Packaged plants cover domestic sewage from buildings and developments as well as industrial effluent. They are not a replacement for large municipal sewage works, which are designed and built as civil projects in their own right.
How the MBBR process works
In an MBBR, the aeration tank is partly filled with small plastic carriers. Air from diffusers keeps them moving and supplies oxygen. Bacteria grow as a biofilm on the protected surfaces of the carriers and break down the dissolved organic load in the wastewater. A screen keeps the carriers inside the tank while the treated water flows on.
Because the bacteria live on the carriers rather than floating freely, a lot of biology fits in a small tank, and the process copes well with changes in load from day to night or between production shifts. Capacity can be extended by adding carriers or tanks when the load grows.
The stages of a typical plant
- Screening to remove rags, plastics and grit that would damage pumps or block the plant.
- Equalisation, a buffer tank that evens out peaks in flow and load.
- The MBBR stage, sometimes in two steps, for the biological treatment.
- Clarification or filtration to separate the sludge from the treated water.
- Disinfection, for example with UV or chlorine, before discharge or reuse.
- Sludge handling, so excess biomass can be removed and taken away.
Industrial effluent may need extra physical or chemical steps before the biology, such as oil separation, pH correction or coagulation. Where the treated water is reused, further polishing with sand and carbon filtration is common.
Where packaged MBBR plants fit in the UAE
Typical applications include buildings and developments without a sewer connection, labour accommodation and remote sites, hotels and resorts that want to reuse treated water for landscaping, and factories that must treat process wastewater before discharge. In each case the reason is the same: a compact, factory-built plant that can be installed quickly and run with limited operator attention.
Where only shower, basin and laundry water is collected separately, a simpler greywater recycling system may be enough. Our article on greywater and wastewater reuse in UAE buildings compares the two routes.
What you need to specify a plant
- The source: domestic sewage, industrial process water or a mix.
- The flow: the daily volume, peak flows and how they vary over the day or week.
- The composition: lab results for parameters such as COD, BOD, suspended solids, nitrogen, oils and pH, ideally from several samples.
- The target: the discharge limits that apply, or the reuse quality required and what the water will be used for.
- The site: available space, whether the plant can be above or below ground, power supply and access for sludge removal.
For new buildings, the design flow is usually estimated from the planned occupancy and use. For existing sites and factories, measured flows and real samples are far more reliable than estimates, because industrial wastewater varies widely between plants.
Operation and maintenance
A well-designed MBBR plant needs regular but simple attention: checking the blowers and pumps, keeping screens clean, removing sludge at the intervals the design sets, and maintaining the disinfection stage. Automation and alarms help keep it running with little attention. Sampling the treated water at agreed intervals shows that the plant still meets its discharge or reuse target.
How AFG can help
AFG manufactures wastewater treatment plants for industrial and domestic wastewater, including packaged MBBR systems, with engineering and manufacturing in Antalya and project support from AFG Dubai. Send the flow, the type of wastewater and any lab results through the quote form, and tell us whether you plan to discharge or reuse the treated water.