Leading the biotech revolution
in wastewater and biogas


BIOPAQ®UASB is the original Upflow Anaerobic Sludge Blanket for biological wastewater treatment and biogas production.

The Upflow Anaerobic Sludge Blanket process is a frequently applied method in the biological treatment of industrial effluents. For decades, Paques has been its global market leader. Nearly four thousand BIOPAQ® UASB modules are in operation worldwide, treating 1,760,000 m3 of effluent per day.

In the BIOPAQ® UASB bioreactor, organic compounds are converted to biogas by bacteria in the absence of air. In this way, effluent discharge costs are reduced and at the same time green energy is produced.

BIOPAQ® UASB technology is applied to treat a large variety of industrial and municipal effluents from food, beer and beverage to pulp & paper, chemical and municipal sewage.

Anaerobic effluent treatment at low TCO

Modular Upflow Anaerobic Sludge Blanket

Paques has standardized the reactor into a modular system. One module has a capacity equivalent to about 1 tonne COD/day (e.g. 15 - 20 m3/hr). This modular approach allows configuring any specific layout and capacity requirement. The modules are available through a worldwide network of licensees.

Additionally, a retrofit programme is available for existing UASB installations. Many clients using a low-rate UASB reactor are struggling with the daily operation of their reactor. Over the years, Paques rebuilt and improved many reactors with typical shortcomings in materials, 3-phase separation and/or influent distribution.

Paques not only has a lot of experience in updating Paques’ installations, but also in improving products of other suppliers.. By implementing an UASB® Rebuild in BIOPAQ® design, improvements were made to UASB's from Biothane, Biotim, Degremont and Seghers, by enhancing the operational stability and increasing the lifespan of the installation.

Advantages of BIOPAQ®UASB

  • COD removal
  • Production of biogas
  • Modular system
  • Low reactor height
  • Corrosion-free design with 10 year guarantee
  • Closed system: no odor emissions

Typical influent characteristics

Characteristic Influent specification
COD level 1,000 to 20,000 mg COD/l
Loading rate 10 to 15 kg COD/m3/day

NB: BIOPAQ®UASBplus is designed for higher COD rates

Working principle

The success of the BIOPAQ®UASB bioreactor is based on the so-called three-phase separator. It enables the reactor to separate gas, water and sludge mixtures under high turbulence conditions. This allows for compact designs.

The patented BIOPAQ®UASB design has multiple gas hoods for the separation of biogas. As a result the extremely large gas/water interfaces greatly reduce turbulence, making relatively high loading rates of 10 – 15 kg/m3.day possible. Separation in the BIOPAQ®UASB requires only 1.0 meter of height, which prevents flotation effects and, consequently, floating layers.


At Paques, we believe in a cleaner, more sustainable world where innovation in biotechnology plays a crucial role in managing our planet's resources wisely.

If you have any questions or wish to explore what Paques technologies can do for your operations, we encourage you to connect with our team of experts. Our knowledgeable professionals are ready to assist you, offering insights and guidance tailored to your specific needs.

Leading the biotech revolution in wastewater and biogas

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Thank you for reaching out to Paques

Your inquiry is important to us, and we are eager to assist you in exploring our innovative solutions for biological wastewater and gas treatment.

A member of our expert team will be in touch shortly to discuss your specific needs and how Paques can help you achieve your environmental and operational goals.

We look forward to collaborating with you and hope to build a cleaner, more sustainable world together.

Warm regards,
The Paques Team