Fluidized Bed Reactor (FBR)

The Technology

The team at Envirogen has a long history of harnessing the science of microbiology to produce high-performance Fluidized Bed Reactor (FBR) systems engineered to eliminate even the most difficult chemicals, such as selenium, nitrate, perchlorate, BTEX and many other, from aqueous streams, providing high-quality, potentially recyclable water and potable water. In fact, we successfully installed a Fluidized Bed Reactor System to treat perchlorate contaminated wells in Southern California, and obtained regulatory approval to deliver potable water to the local communities. Using non-pathogenic, naturally occurring bacteria, and nutrients to facilitate bacteria growth, the Fluidized Bed Reactor transforms toxic contaminants so they can be safely removed, thus delivering a green solution to address difficult contaminants.

US Patents: 6706521, 5750028, 5788842, 7754159, 7611890, 7572626, 8323496, 6830922

Our Product

For a broad range of influent flow rates and contaminant concentration levels, our Fluidized Bed Reactor (FBR) system is often the most economical treatment choice. With aerobic, anaerobic and anoxic designs available, systems have been successfully operated at ranges from 5 to 6,000 GPM, yielding high performance paired with low capital and operating costs.


Small footprint/Efficient – High concentration of biomass, plug-flow characteristics and tall beds minimize bioreactor footprint. High biomass concentration means long Solid Retention Time (SRT) and short Hydraulic Retention Time (HRT) and a high-quality effluent

Steady-state performance – FBRs run continuously without backwashing or cleaning operations.

Proven design – Envirogen’s Fluidized Bed Reactors have been continually improved and refined based on lessons learned over 30+ years of design and operating experiences.

Robust – Does not plug up or channel. Tolerant of high feed Total Suspended Solids (TSS) and metals. Proven robust performance and ability to quickly recover from upsets such as power outages or loss of chemical feeds. Capable of handling both hydraulic and organic shock loads.

Flexible – Operates effectively over a wide range of feed flow and qualities. Actual treatment technology (“green”), not just a phase transfer treatment for most contaminants.

Cost effective – Envirogen’s Fluidized Bed Reactors are cost effective across a wide range of contaminants treated


Whatever the problem – chemicals, aromatics, alcohols, ketones, chlorinated solvents, Polycyclic aromatic hydrocarbons (PAH), 1,4-Dioxane, chromium hydrocarbons, BTEX (Benzene, Toluene, Ethylbenzene and Xylene), selenium, perchlorates or nitrates – the FBR system handles high flows at low cost with typical treatment efficiencies of 99 percent or higher.

Additionally, this is one of the most efficient denitrification processes available today. Our FBR denitrification process lowers discharge levels of nitrogen in wastewater to less than 0.1 mg/l NO3-N. This simple end-of-pipe solution can use different carbon sources, does not require backwashing, produces minimal biosolids, and does not have filter upsets due to accumulating nitrogen bubbles.

One application where the FBR is well suited is for denitrification of the Flue Gas Desulfurization wastewater produced in coal fired power plants.  Specifically, Envirogen’s FBR can be inserted into existing chemical precipitation processes (as depicted in the image below) to reduce the nitrate load on the downstream biological system, thereby improving selenium compliance. Removing nitrate up-front can also reduce the size and cost of downstream biological treatment.  Read more about our experience in Power Plants.

Envirogen Experience